diff --git a/test/client/accounts/accounts-manager-test.vala b/test/client/accounts/accounts-manager-test.vala
index 5a883957..0495133f 100644
--- a/test/client/accounts/accounts-manager-test.vala
+++ b/test/client/accounts/accounts-manager-test.vala
@@ -82,7 +82,7 @@ class Accounts.ManagerTest : TestCase {
 
         this.test.create_account.begin(
             account, new GLib.Cancellable(),
-             (obj, res) => { async_complete(res); }
+             this.async_completion
         );
         this.test.create_account.end(async_result());
 
@@ -95,7 +95,7 @@ class Accounts.ManagerTest : TestCase {
     public void create_orphan_account() throws GLib.Error {
         this.test.new_orphan_account.begin(
             Geary.ServiceProvider.OTHER, this.primary_mailbox, null,
-            (obj, res) => { async_complete(res); }
+            this.async_completion
         );
         Geary.AccountInformation account1 =
             this.test.new_orphan_account.end(async_result());
@@ -103,13 +103,13 @@ class Accounts.ManagerTest : TestCase {
 
         this.test.create_account.begin(
             account1, new GLib.Cancellable(),
-            (obj, res) => { async_complete(res); }
+            this.async_completion
         );
         this.test.create_account.end(async_result());
 
         this.test.new_orphan_account.begin(
             Geary.ServiceProvider.OTHER, this.primary_mailbox, null,
-            (obj, res) => { async_complete(res); }
+            this.async_completion
         );
         Geary.AccountInformation account2 =
             this.test.new_orphan_account.end(async_result());
@@ -119,13 +119,13 @@ class Accounts.ManagerTest : TestCase {
     public void create_orphan_account_with_legacy() throws GLib.Error {
         this.test.create_account.begin(
             account, new GLib.Cancellable(),
-            (obj, res) => { async_complete(res); }
+            this.async_completion
         );
         this.test.create_account.end(async_result());
 
         this.test.new_orphan_account.begin(
             Geary.ServiceProvider.OTHER, this.primary_mailbox, null,
-            (obj, res) => { async_complete(res); }
+            this.async_completion
         );
         Geary.AccountInformation account1 =
             this.test.new_orphan_account.end(async_result());
@@ -133,13 +133,13 @@ class Accounts.ManagerTest : TestCase {
 
         this.test.create_account.begin(
             account1, new GLib.Cancellable(),
-            (obj, res) => { async_complete(res); }
+            this.async_completion
         );
         this.test.create_account.end(async_result());
 
         this.test.new_orphan_account.begin(
             Geary.ServiceProvider.OTHER, this.primary_mailbox, null,
-            (obj, res) => { async_complete(res); }
+            this.async_completion
         );
         Geary.AccountInformation account2 =
             this.test.new_orphan_account.end(async_result());
@@ -154,7 +154,7 @@ class Accounts.ManagerTest : TestCase {
 
         this.test.new_orphan_account.begin(
             Geary.ServiceProvider.OTHER, this.primary_mailbox, null,
-            (obj, res) => { async_complete(res); }
+            this.async_completion
         );
         Geary.AccountInformation account =
             this.test.new_orphan_account.end(async_result());
diff --git a/test/client/components/client-web-view-test-case.vala b/test/client/components/client-web-view-test-case.vala
index d1212afb..a1abab26 100644
--- a/test/client/components/client-web-view-test-case.vala
+++ b/test/client/components/client-web-view-test-case.vala
@@ -43,10 +43,7 @@ public abstract class ClientWebViewTestCase<V> : TestCase {
 
     protected WebKit.JavascriptResult run_javascript(string command) throws Error {
         ClientWebView view = (ClientWebView) this.test_view;
-        view.run_javascript.begin(
-            command, null, (obj, res) => { async_complete(res); }
-        );
-
+        view.run_javascript.begin(command, null, this.async_completion);
         return view.run_javascript.end(async_result());
     }
 
diff --git a/test/client/composer/composer-web-view-test.vala b/test/client/composer/composer-web-view-test.vala
index bac7e7f0..2d2f25a0 100644
--- a/test/client/composer/composer-web-view-test.vala
+++ b/test/client/composer/composer-web-view-test.vala
@@ -54,7 +54,7 @@ public class Composer.WebViewTest : ClientWebViewTestCase<Composer.WebView> {
     public void get_html() throws GLib.Error {
         string BODY = "<p>para</p>";
         load_body_fixture(BODY);
-        this.test_view.get_html.begin((obj, ret) => { async_complete(ret); });
+        this.test_view.get_html.begin(this.async_completion);
         string html = this.test_view.get_html.end(async_result());
         assert_string(PageStateTest.CLEAN_BODY_TEMPLATE.printf(BODY), html);
     }
@@ -62,14 +62,14 @@ public class Composer.WebViewTest : ClientWebViewTestCase<Composer.WebView> {
     public void get_html_for_draft() throws GLib.Error {
         string BODY = "<p>para</p>";
         load_body_fixture(BODY);
-        this.test_view.get_html_for_draft.begin((obj, ret) => { async_complete(ret); });
+        this.test_view.get_html_for_draft.begin(this.async_completion);
         string html = this.test_view.get_html.end(async_result());
         assert_string(PageStateTest.COMPLETE_BODY_TEMPLATE.printf(BODY), html);
     }
 
     public void get_text() throws Error {
         load_body_fixture("<p>para</p>");
-        this.test_view.get_text.begin((obj, ret) => { async_complete(ret); });
+        this.test_view.get_text.begin(this.async_completion);
         try {
             assert(this.test_view.get_text.end(async_result()) == "para\n\n\n\n\n");
         } catch (Error err) {
@@ -80,7 +80,7 @@ public class Composer.WebViewTest : ClientWebViewTestCase<Composer.WebView> {
 
     public void get_text_with_quote() throws Error {
         load_body_fixture("<p>pre</p> <blockquote><p>quote</p></blockquote> <p>post</p>");
-        this.test_view.get_text.begin((obj, ret) => { async_complete(ret); });
+        this.test_view.get_text.begin(this.async_completion);
         try {
             assert(this.test_view.get_text.end(async_result()) ==
                    "pre\n\n> quote\n> \npost\n\n\n\n\n");
@@ -92,7 +92,7 @@ public class Composer.WebViewTest : ClientWebViewTestCase<Composer.WebView> {
 
     public void get_text_with_nested_quote() throws Error {
         load_body_fixture("<p>pre</p> <blockquote><p>quote1</p> <blockquote><p>quote2</p></blockquote></blockquote> <p>post</p>");
-        this.test_view.get_text.begin((obj, ret) => { async_complete(ret); });
+        this.test_view.get_text.begin(this.async_completion);
         try {
             assert(this.test_view.get_text.end(async_result()) ==
                    "pre\n\n> quote1\n> \n>> quote2\n>> \npost\n\n\n\n\n");
@@ -107,7 +107,7 @@ public class Composer.WebViewTest : ClientWebViewTestCase<Composer.WebView> {
 <p>A long, long, long, long, long, long para. Well, longer than MAX_BREAKABLE_LEN
 at least. Really long, long, long, long, long long, long long, long long, long.</p>
 """);
-        this.test_view.get_text.begin((obj, ret) => { async_complete(ret); });
+        this.test_view.get_text.begin(this.async_completion);
         try {
             assert(this.test_view.get_text.end(async_result()) ==
 """A long, long, long, long, long, long para. Well, longer than 
@@ -130,7 +130,7 @@ long long, long long, long.
 
 <p>A long, long, long, long, long, long para. Well, longer than MAX_BREAKABLE_LEN
 at least. Really long, long, long, long, long long, long long, long long, long.</p>""");
-        this.test_view.get_text.begin((obj, ret) => { async_complete(ret); });
+        this.test_view.get_text.begin(this.async_completion);
         try {
             assert(this.test_view.get_text.end(async_result()) ==
 """> A long, long, long, long, long, long line. Well, longer than 
@@ -157,7 +157,7 @@ long long, long long, long.
 </div>
 
 """);
-        this.test_view.get_text.begin((obj, ret) => { async_complete(ret); });
+        this.test_view.get_text.begin(this.async_completion);
         try {
             assert(this.test_view.get_text.end(async_result()) ==
 """On Sun, Jan 1, 2017 at 9:55 PM, Michael Gratton <mike@vee.net> wrote:
@@ -185,7 +185,7 @@ long, long, long, long, long, long, long, long, long, long,
 
     public void get_text_with_named_link() throws Error {
         load_body_fixture("Check out <a href=\"https://wiki.gnome.org/Apps/Geary\">Geary</a>!");
-        this.test_view.get_text.begin((obj, ret) => { async_complete(ret); });
+        this.test_view.get_text.begin(this.async_completion);
         try {
             assert(this.test_view.get_text.end(async_result()) ==
                    "Check out Geary <https://wiki.gnome.org/Apps/Geary>!\n\n\n\n");
@@ -197,7 +197,7 @@ long, long, long, long, long, long, long, long, long, long,
 
     public void get_text_with_url_link() throws Error {
         load_body_fixture("Check out <a href=\"https://wiki.gnome.org/Apps/Geary\">https://wiki.gnome.org/Apps/Geary</a>!");
-        this.test_view.get_text.begin((obj, ret) => { async_complete(ret); });
+        this.test_view.get_text.begin(this.async_completion);
         try {
             assert(this.test_view.get_text.end(async_result()) ==
                    "Check out <https://wiki.gnome.org/Apps/Geary>!\n\n\n\n");
@@ -209,7 +209,7 @@ long, long, long, long, long, long, long, long, long, long,
 
     public void get_text_with_surrounding_nbsps() throws Error {
         load_body_fixture("&nbsp;&nbsp;I like my space&nbsp;&nbsp;");
-        this.test_view.get_text.begin((obj, ret) => { async_complete(ret); });
+        this.test_view.get_text.begin(this.async_completion);
         try {
             assert(this.test_view.get_text.end(async_result()) ==
                    "  I like my space\n\n\n\n");
@@ -226,21 +226,21 @@ long, long, long, long, long, long, long, long, long, long,
 
         const string SIG1 = "signature text 1";
         this.test_view.update_signature(SIG1);
-        this.test_view.get_html.begin((obj, ret) => { async_complete(ret); });
+        this.test_view.get_html.begin(this.async_completion);
         html = this.test_view.get_html.end(async_result());
         assert_true(BODY in html, "Body not present");
         assert_true(SIG1 in html, "Signature 1 not present");
 
         const string SIG2 = "signature text 2";
         this.test_view.update_signature(SIG2);
-        this.test_view.get_html.begin((obj, ret) => { async_complete(ret); });
+        this.test_view.get_html.begin(this.async_completion);
         html = this.test_view.get_html.end(async_result());
         assert_true(BODY in html, "Body not present");
         assert_false(SIG1 in html, "Signature 1 still present");
         assert_true(SIG2 in html, "Signature 2 not present");
 
         this.test_view.update_signature("");
-        this.test_view.get_html.begin((obj, ret) => { async_complete(ret); });
+        this.test_view.get_html.begin(this.async_completion);
         html = this.test_view.get_html.end(async_result());
         assert_true(BODY in html, "Body not present");
         assert_false(SIG1 in html, "Signature 1 still present");
diff --git a/test/engine/api/geary-attachment-test.vala b/test/engine/api/geary-attachment-test.vala
index 814ca7b7..6db441cf 100644
--- a/test/engine/api/geary-attachment-test.vala
+++ b/test/engine/api/geary-attachment-test.vala
@@ -83,9 +83,7 @@ class Geary.AttachmentTest : TestCase {
             this.file
         );
 
-        test.get_safe_file_name.begin(null, (obj, ret) => {
-                async_complete(ret);
-            });
+        test.get_safe_file_name.begin(null, this.async_completion);
 
         assert(test.get_safe_file_name.end(async_result()) == TEST_FILENAME);
     }
@@ -102,9 +100,7 @@ class Geary.AttachmentTest : TestCase {
             this.file
         );
 
-        test.get_safe_file_name.begin(null, (obj, ret) => {
-                async_complete(ret);
-            });
+        test.get_safe_file_name.begin(null, this.async_completion);
 
         assert(test.get_safe_file_name.end(async_result()) == RESULT_FILENAME);
     }
@@ -121,9 +117,7 @@ class Geary.AttachmentTest : TestCase {
             this.file
         );
 
-        test.get_safe_file_name.begin(null, (obj, ret) => {
-                async_complete(ret);
-            });
+        test.get_safe_file_name.begin(null, this.async_completion);
 
         assert(test.get_safe_file_name.end(async_result()) == RESULT_FILENAME);
     }
@@ -139,9 +133,7 @@ class Geary.AttachmentTest : TestCase {
             this.file
         );
 
-        test.get_safe_file_name.begin(null, (obj, ret) => {
-                async_complete(ret);
-            });
+        test.get_safe_file_name.begin(null, this.async_completion);
 
         assert(test.get_safe_file_name.end(async_result()) == RESULT_FILENAME);
     }
@@ -157,9 +149,7 @@ class Geary.AttachmentTest : TestCase {
             this.file
         );
 
-        test.get_safe_file_name.begin(null, (obj, ret) => {
-                async_complete(ret);
-            });
+        test.get_safe_file_name.begin(null, this.async_completion);
 
         assert(test.get_safe_file_name.end(async_result()) == RESULT_FILENAME);
     }
@@ -176,9 +166,7 @@ class Geary.AttachmentTest : TestCase {
             this.file
         );
 
-        test.get_safe_file_name.begin(ALT_TEXT, (obj, ret) => {
-                async_complete(ret);
-            });
+        test.get_safe_file_name.begin(ALT_TEXT, this.async_completion);
 
         assert(test.get_safe_file_name.end(async_result()) == RESULT_FILENAME);
     }
@@ -194,9 +182,7 @@ class Geary.AttachmentTest : TestCase {
             this.file
         );
 
-        test.get_safe_file_name.begin(null, (obj, ret) => {
-                async_complete(ret);
-            });
+        test.get_safe_file_name.begin(null, this.async_completion);
 
         assert(test.get_safe_file_name.end(async_result()) == TEST_FILENAME);
     }
@@ -214,9 +200,7 @@ class Geary.AttachmentTest : TestCase {
             this.file
         );
 
-        test.get_safe_file_name.begin(null, (obj, ret) => {
-                async_complete(ret);
-            });
+        test.get_safe_file_name.begin(null, this.async_completion);
 
         assert(test.get_safe_file_name.end(async_result()) == RESULT_FILENAME);
     }
@@ -233,9 +217,7 @@ class Geary.AttachmentTest : TestCase {
             File.new_for_path(TEST_FILENAME)
         );
 
-        test.get_safe_file_name.begin(null, (obj, ret) => {
-                async_complete(ret);
-            });
+        test.get_safe_file_name.begin(null, this.async_completion);
 
         assert_string(TEST_FILENAME, test.get_safe_file_name.end(async_result()));
     }
diff --git a/test/engine/app/app-conversation-monitor-test.vala b/test/engine/app/app-conversation-monitor-test.vala
index 81043dca..3bec1de7 100644
--- a/test/engine/app/app-conversation-monitor-test.vala
+++ b/test/engine/app/app-conversation-monitor-test.vala
@@ -78,7 +78,7 @@ class Geary.App.ConversationMonitorTest : TestCase {
         this.base_folder.expect_call("close_async");
 
         monitor.start_monitoring.begin(
-            NONE, test_cancellable, (obj, res) => { async_complete(res); }
+            NONE, test_cancellable, this.async_completion
         );
         monitor.start_monitoring.end(async_result());
 
@@ -88,7 +88,7 @@ class Geary.App.ConversationMonitorTest : TestCase {
         }
 
         monitor.stop_monitoring.begin(
-            test_cancellable, (obj, res) => { async_complete(res); }
+            test_cancellable, this.async_completion
         );
         monitor.stop_monitoring.end(async_result());
 
@@ -108,7 +108,7 @@ class Geary.App.ConversationMonitorTest : TestCase {
             .throws(new EngineError.SERVER_UNAVAILABLE("Mock error"));
 
         monitor.start_monitoring.begin(
-            NONE, null, (obj, res) => { async_complete(res); }
+            NONE, null, this.async_completion
         );
         try {
             monitor.start_monitoring.end(async_result());
@@ -246,7 +246,7 @@ class Geary.App.ConversationMonitorTest : TestCase {
         // error out during later tests
         this.base_folder.expect_call("close_async");
         monitor.stop_monitoring.begin(
-            null, (obj, res) => { async_complete(res); }
+            null, this.async_completion
         );
         monitor.stop_monitoring.end(async_result());
     }
@@ -477,7 +477,7 @@ class Geary.App.ConversationMonitorTest : TestCase {
         }
 
         monitor.start_monitoring.begin(
-            NONE, test_cancellable, (obj, res) => { async_complete(res); }
+            NONE, test_cancellable, this.async_completion
         );
         monitor.start_monitoring.end(async_result());
 
diff --git a/test/engine/common/common-contact-harvester-test.vala b/test/engine/common/common-contact-harvester-test.vala
index fcb7bf2a..fb5efbf7 100644
--- a/test/engine/common/common-contact-harvester-test.vala
+++ b/test/engine/common/common-contact-harvester-test.vala
@@ -64,9 +64,7 @@ class Geary.ContactHarvesterImplTest : TestCase {
         );
 
         whitelisted.harvest_from_email.begin(
-            Collection.single(this.email), null,
-            (obj, ret) => { async_complete(ret); }
-        );
+            Collection.single(this.email), null, this.async_completion);
         whitelisted.harvest_from_email.end(async_result());
 
         this.store.assert_expectations();
@@ -92,9 +90,7 @@ class Geary.ContactHarvesterImplTest : TestCase {
         );
 
         whitelisted.harvest_from_email.begin(
-            Collection.single(this.email), null,
-            (obj, ret) => { async_complete(ret); }
-        );
+            Collection.single(this.email), null, this.async_completion);
         whitelisted.harvest_from_email.end(async_result());
 
         this.store.assert_expectations();
@@ -113,9 +109,7 @@ class Geary.ContactHarvesterImplTest : TestCase {
         );
 
         whitelisted.harvest_from_email.begin(
-            Collection.single(this.email), null,
-            (obj, ret) => { async_complete(ret); }
-        );
+            Collection.single(this.email), null, this.async_completion);
         whitelisted.harvest_from_email.end(async_result());
 
         this.store.assert_expectations();
@@ -142,9 +136,7 @@ class Geary.ContactHarvesterImplTest : TestCase {
         );
 
         whitelisted.harvest_from_email.begin(
-            Collection.single(this.email), null,
-            (obj, ret) => { async_complete(ret); }
-        );
+            Collection.single(this.email), null, this.async_completion);
         whitelisted.harvest_from_email.end(async_result());
 
         this.store.assert_expectations();
@@ -171,9 +163,7 @@ class Geary.ContactHarvesterImplTest : TestCase {
         );
 
         whitelisted.harvest_from_email.begin(
-            Collection.single(this.email), null,
-            (obj, ret) => { async_complete(ret); }
-        );
+            Collection.single(this.email), null, this.async_completion);
         whitelisted.harvest_from_email.end(async_result());
 
         this.store.assert_expectations();
diff --git a/test/engine/common/common-contact-store-impl-test.vala b/test/engine/common/common-contact-store-impl-test.vala
index 2bc50dea..2e65e776 100644
--- a/test/engine/common/common-contact-store-impl-test.vala
+++ b/test/engine/common/common-contact-store-impl-test.vala
@@ -42,7 +42,7 @@ class Geary.ContactStoreImplTest : TestCase {
         );
         this.db.open.begin(
             Geary.Db.DatabaseFlags.CREATE_FILE, null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         this.db.open.end(async_result());
 
@@ -79,7 +79,7 @@ class Geary.ContactStoreImplTest : TestCase {
         test_article.get_by_rfc822.begin(
             new RFC822.MailboxAddress(null, "Test@example.com"),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         Contact? existing = test_article.get_by_rfc822.end(async_result());
         assert_non_null(existing, "Existing contact");
@@ -92,7 +92,7 @@ class Geary.ContactStoreImplTest : TestCase {
         test_article.get_by_rfc822.begin(
             new RFC822.MailboxAddress(null, "test@example.com"),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         Contact? missing = test_article.get_by_rfc822.end(async_result());
         assert_null(missing, "Missing contact");
@@ -104,7 +104,7 @@ class Geary.ContactStoreImplTest : TestCase {
             0,
             10,
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         Gee.Collection<Contact> results = test_article.search.end(
             async_result()
@@ -118,7 +118,7 @@ class Geary.ContactStoreImplTest : TestCase {
             0,
             10,
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         Gee.Collection<Contact> results = test_article.search.end(
             async_result()
@@ -139,7 +139,7 @@ class Geary.ContactStoreImplTest : TestCase {
             0,
             10,
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         Gee.Collection<Contact> results = test_article.search.end(
             async_result()
@@ -173,7 +173,7 @@ class Geary.ContactStoreImplTest : TestCase {
             0,
             10,
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         Gee.Collection<Contact> results = test_article.search.end(
             async_result()
@@ -204,7 +204,7 @@ class Geary.ContactStoreImplTest : TestCase {
             0,
             10,
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         Gee.Collection<Contact> results = test_article.search.end(
             async_result()
@@ -226,14 +226,14 @@ class Geary.ContactStoreImplTest : TestCase {
         test_article.update_contacts.begin(
             Collection.single(not_persisted),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         test_article.update_contacts.end(async_result());
 
         test_article.get_by_rfc822.begin(
             new RFC822.MailboxAddress(null, "New@example.com"),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         Contact? persisted = test_article.get_by_rfc822.end(async_result());
         assert_non_null(persisted, "persisted");
@@ -255,13 +255,13 @@ class Geary.ContactStoreImplTest : TestCase {
         test_article.update_contacts.begin(
             Collection.single(not_updated),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         test_article.update_contacts.end(async_result());
         test_article.get_by_rfc822.begin(
             new RFC822.MailboxAddress(null, "Test@example.com"),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         Contact? updated = test_article.get_by_rfc822.end(async_result());
         assert_non_null(updated, "updated");
@@ -276,13 +276,13 @@ class Geary.ContactStoreImplTest : TestCase {
         test_article.update_contacts.begin(
             Collection.single(not_updated),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         test_article.update_contacts.end(async_result());
         test_article.get_by_rfc822.begin(
             new RFC822.MailboxAddress(null, "Test@example.com"),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         Contact? updated_again = test_article.get_by_rfc822.end(async_result());
         assert_false(updated_again.flags.always_load_remote_images(), "Removed flags");
diff --git a/test/engine/db/db-database-test.vala b/test/engine/db/db-database-test.vala
index c8e746bd..2a72bccd 100644
--- a/test/engine/db/db-database-test.vala
+++ b/test/engine/db/db-database-test.vala
@@ -21,10 +21,7 @@ class Geary.Db.DatabaseTest : TestCase {
 
     public void transient_open() throws Error {
         Database db = new Geary.Db.Database.transient();
-        db.open.begin(
-            Geary.Db.DatabaseFlags.NONE, null,
-            (obj, ret) => { async_complete(ret); }
-        );
+        db.open.begin(Geary.Db.DatabaseFlags.NONE, null, this.async_completion);
         db.open.end(async_result());
 
         // Need to get a connection since the database doesn't
@@ -39,10 +36,7 @@ class Geary.Db.DatabaseTest : TestCase {
         );
 
         Database db = new Geary.Db.Database.persistent(tmp_file);
-        db.open.begin(
-            Geary.Db.DatabaseFlags.NONE, null,
-            (obj, ret) => { async_complete(ret); }
-        );
+        db.open.begin(Geary.Db.DatabaseFlags.NONE, null, this.async_completion);
         db.open.end(async_result());
 
         // Need to get a connection since the database doesn't
@@ -61,8 +55,7 @@ class Geary.Db.DatabaseTest : TestCase {
             tmp_dir.get_child("test.db")
         );
         db.open.begin(
-            Geary.Db.DatabaseFlags.CREATE_FILE, null,
-            (obj, ret) => { async_complete(ret); }
+            Geary.Db.DatabaseFlags.CREATE_FILE, null, this.async_completion
         );
         db.open.end(async_result());
 
@@ -86,7 +79,7 @@ class Geary.Db.DatabaseTest : TestCase {
             Geary.Db.DatabaseFlags.CREATE_DIRECTORY |
             Geary.Db.DatabaseFlags.CREATE_FILE,
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         db.open.end(async_result());
 
@@ -111,7 +104,7 @@ class Geary.Db.DatabaseTest : TestCase {
             Geary.Db.DatabaseFlags.CREATE_DIRECTORY |
             Geary.Db.DatabaseFlags.CREATE_FILE,
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         db.open.end(async_result());
 
@@ -135,7 +128,7 @@ class Geary.Db.DatabaseTest : TestCase {
             Geary.Db.DatabaseFlags.CREATE_FILE |
             Geary.Db.DatabaseFlags.CHECK_CORRUPTION,
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         db.open.end(async_result());
 
@@ -160,7 +153,7 @@ class Geary.Db.DatabaseTest : TestCase {
             Geary.Db.DatabaseFlags.CREATE_FILE |
             Geary.Db.DatabaseFlags.CHECK_CORRUPTION,
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         db.open.end(async_result());
 
diff --git a/test/engine/db/db-versioned-database-test.vala b/test/engine/db/db-versioned-database-test.vala
index 4e12962f..53ac49ee 100644
--- a/test/engine/db/db-versioned-database-test.vala
+++ b/test/engine/db/db-versioned-database-test.vala
@@ -34,8 +34,7 @@ class Geary.Db.VersionedDatabaseTest : TestCase {
         );
 
         db.open.begin(
-            Geary.Db.DatabaseFlags.CREATE_FILE, null,
-            (obj, ret) => { async_complete(ret); }
+            Geary.Db.DatabaseFlags.CREATE_FILE, null, this.async_completion
         );
         db.open.end(async_result());
 
diff --git a/test/engine/imap-db/imap-db-account-test.vala b/test/engine/imap-db/imap-db-account-test.vala
index 61b62506..c526372d 100644
--- a/test/engine/imap-db/imap-db-account-test.vala
+++ b/test/engine/imap-db/imap-db-account-test.vala
@@ -48,7 +48,7 @@ class Geary.ImapDB.AccountTest : TestCase {
         );
         this.account.open_async.begin(
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         this.account.open_async.end(async_result());
 
@@ -59,7 +59,7 @@ class Geary.ImapDB.AccountTest : TestCase {
         this.root = null;
         this.account.close_async.begin(
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         this.account.close_async.end(async_result());
         this.account = null;
@@ -91,7 +91,7 @@ class Geary.ImapDB.AccountTest : TestCase {
         this.account.clone_folder_async.begin(
             folder,
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         this.account.clone_folder_async.end(async_result());
 
@@ -130,7 +130,7 @@ class Geary.ImapDB.AccountTest : TestCase {
         this.account.clone_folder_async.begin(
             folder,
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         this.account.clone_folder_async.end(async_result());
 
@@ -155,7 +155,7 @@ class Geary.ImapDB.AccountTest : TestCase {
         this.account.list_folders_async.begin(
             this.account.imap_folder_root,
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         Gee.Collection<Geary.ImapDB.Folder> result =
             this.account.list_folders_async.end(async_result());
@@ -167,7 +167,7 @@ class Geary.ImapDB.AccountTest : TestCase {
         this.account.list_folders_async.begin(
             test1.get_path(),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         result = this.account.list_folders_async.end(async_result());
 
@@ -178,7 +178,7 @@ class Geary.ImapDB.AccountTest : TestCase {
         this.account.list_folders_async.begin(
             test2.get_path(),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         result = this.account.list_folders_async.end(async_result());
 
@@ -198,14 +198,14 @@ class Geary.ImapDB.AccountTest : TestCase {
         this.account.delete_folder_async.begin(
             this.root.get_child("test1").get_child("test2"),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         this.account.delete_folder_async.end(async_result());
 
         this.account.delete_folder_async.begin(
             this.root.get_child("test1"),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         this.account.delete_folder_async.end(async_result());
     }
@@ -221,7 +221,7 @@ class Geary.ImapDB.AccountTest : TestCase {
         this.account.delete_folder_async.begin(
             this.root.get_child("test1"),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         try {
             this.account.delete_folder_async.end(async_result());
@@ -242,7 +242,7 @@ class Geary.ImapDB.AccountTest : TestCase {
         this.account.delete_folder_async.begin(
             this.root.get_child("test3"),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         try {
             this.account.delete_folder_async.end(async_result());
@@ -263,7 +263,7 @@ class Geary.ImapDB.AccountTest : TestCase {
         this.account.fetch_folder_async.begin(
             this.root.get_child("test1"),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
 
         Folder? result = this.account.fetch_folder_async.end(async_result());
@@ -282,7 +282,7 @@ class Geary.ImapDB.AccountTest : TestCase {
         this.account.fetch_folder_async.begin(
             this.root.get_child("test1").get_child("test2"),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
 
         Folder? result = this.account.fetch_folder_async.end(async_result());
@@ -301,7 +301,7 @@ class Geary.ImapDB.AccountTest : TestCase {
         this.account.fetch_folder_async.begin(
             this.root.get_child("test3"),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         try {
             this.account.fetch_folder_async.end(async_result());
@@ -330,7 +330,7 @@ class Geary.ImapDB.AccountTest : TestCase {
                 }).to_linked_list(),
             Email.Field.RECEIVERS,
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         Gee.List<Email> result = this.account.list_email.end(
             async_result()
@@ -344,7 +344,7 @@ class Geary.ImapDB.AccountTest : TestCase {
             Collection.single(new EmailIdentifier(3, null)),
             Email.Field.RECEIVERS,
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         try {
             this.account.list_email.end(async_result());
@@ -357,7 +357,7 @@ class Geary.ImapDB.AccountTest : TestCase {
             Collection.single(new EmailIdentifier(1, null)),
             Email.Field.BODY,
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         try {
             this.account.list_email.end(async_result());
diff --git a/test/engine/imap-db/imap-db-attachment-test.vala b/test/engine/imap-db/imap-db-attachment-test.vala
index bf201b70..e8e2f260 100644
--- a/test/engine/imap-db/imap-db-attachment-test.vala
+++ b/test/engine/imap-db/imap-db-attachment-test.vala
@@ -119,7 +119,7 @@ class Geary.ImapDB.AttachmentIoTest : TestCase {
         this.db = new Geary.Db.Database.transient();
         this.db.open.begin(
             Geary.Db.DatabaseFlags.NONE, null,
-            (obj, res) => { async_complete(res); }
+            this.async_completion
         );
         this.db.open.end(async_result());
         this.db.exec("""
@@ -150,7 +150,7 @@ CREATE TABLE MessageAttachmentTable (
 
         Files.recursive_delete_async.begin(
             this.tmp_dir, GLib.Priority.DEFAULT, null,
-            (obj, res) => { async_complete(res); }
+            this.async_completion
         );
         Files.recursive_delete_async.end(async_result());
         this.tmp_dir = null;
diff --git a/test/engine/imap-db/imap-db-database-test.vala b/test/engine/imap-db/imap-db-database-test.vala
index 1341f2d8..1fb73683 100644
--- a/test/engine/imap-db/imap-db-database-test.vala
+++ b/test/engine/imap-db/imap-db-database-test.vala
@@ -42,7 +42,7 @@ class Geary.ImapDB.DatabaseTest : TestCase {
 
         db.open.begin(
             Geary.Db.DatabaseFlags.CREATE_FILE, null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         db.open.end(async_result());
 
@@ -102,7 +102,7 @@ class Geary.ImapDB.DatabaseTest : TestCase {
 
         db.open.begin(
             Geary.Db.DatabaseFlags.CREATE_FILE, null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         db.open.end(async_result());
 
@@ -136,7 +136,7 @@ class Geary.ImapDB.DatabaseTest : TestCase {
 
         db.open.begin(
             Geary.Db.DatabaseFlags.CREATE_FILE, null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         db.open.end(async_result());
 
diff --git a/test/engine/imap-db/imap-db-folder-test.vala b/test/engine/imap-db/imap-db-folder-test.vala
index 496afd10..17baabdc 100644
--- a/test/engine/imap-db/imap-db-folder-test.vala
+++ b/test/engine/imap-db/imap-db-folder-test.vala
@@ -47,7 +47,7 @@ class Geary.ImapDB.FolderTest : TestCase {
         );
         this.account.open_async.begin(
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         this.account.open_async.end(async_result());
 
@@ -58,7 +58,7 @@ class Geary.ImapDB.FolderTest : TestCase {
         this.account.list_folders_async.begin(
             this.account.imap_folder_root,
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         this.folder = traverse<Folder>(
             this.account.list_folders_async.end(async_result())
@@ -69,7 +69,7 @@ class Geary.ImapDB.FolderTest : TestCase {
         this.folder = null;
         this.account.close_async.begin(
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         this.account.close_async.end(async_result());
         this.account = null;
@@ -87,7 +87,7 @@ class Geary.ImapDB.FolderTest : TestCase {
             true,
             new MockContactHarvester(),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         Gee.Map<Email,bool> results =
             this.folder.create_or_merge_email_async.end(async_result());
@@ -107,7 +107,7 @@ class Geary.ImapDB.FolderTest : TestCase {
             true,
             new MockContactHarvester(),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         Gee.Map<Email,bool> results =
             this.folder.create_or_merge_email_async.end(async_result());
@@ -127,7 +127,7 @@ class Geary.ImapDB.FolderTest : TestCase {
             false,
             new MockContactHarvester(),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         Gee.Map<Email,bool> results =
             this.folder.create_or_merge_email_async.end(async_result());
@@ -157,7 +157,7 @@ class Geary.ImapDB.FolderTest : TestCase {
             true,
             new MockContactHarvester(),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         Gee.Map<Email,bool> results =
             this.folder.create_or_merge_email_async.end(async_result());
@@ -172,7 +172,7 @@ class Geary.ImapDB.FolderTest : TestCase {
             fixture_fields | mock.fields,
             Folder.ListFlags.NONE,
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         Email? merged = null;
         try {
@@ -208,7 +208,7 @@ class Geary.ImapDB.FolderTest : TestCase {
             true,
             new MockContactHarvester(),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         Gee.Map<Email,bool> results =
             this.folder.create_or_merge_email_async.end(async_result());
@@ -242,7 +242,7 @@ class Geary.ImapDB.FolderTest : TestCase {
             true,
             new MockContactHarvester(),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         Gee.Map<Email,bool> results =
             this.folder.create_or_merge_email_async.end(async_result());
@@ -280,7 +280,7 @@ class Geary.ImapDB.FolderTest : TestCase {
         this.folder.set_email_flags_async.begin(
             Collection.single_map(test, test_flags),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         this.folder.set_email_flags_async.end(async_result());
 
@@ -316,7 +316,7 @@ class Geary.ImapDB.FolderTest : TestCase {
         this.folder.set_email_flags_async.begin(
             Collection.single_map(test, test_flags),
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         this.folder.set_email_flags_async.end(async_result());
 
@@ -347,7 +347,7 @@ class Geary.ImapDB.FolderTest : TestCase {
             Email.Field.FLAGS,
             Folder.ListFlags.INCLUDE_MARKED_FOR_REMOVE,
             null,
-            (obj, ret) => { async_complete(ret); }
+            this.async_completion
         );
         Email? merged = null;
         try {
diff --git a/test/engine/imap-engine/imap-engine-generic-account-test.vala b/test/engine/imap-engine/imap-engine-generic-account-test.vala
index b22af954..6225970f 100644
--- a/test/engine/imap-engine/imap-engine-generic-account-test.vala
+++ b/test/engine/imap-engine/imap-engine-generic-account-test.vala
@@ -57,18 +57,12 @@ public class Geary.ImapEngine.GenericAccountTest : TestCase {
             this.tmp_dir,
             GLib.File.new_for_path(_SOURCE_ROOT_DIR).get_child("sql")
         );
-        this.local_account.open_async.begin(
-            null,
-            (obj, ret) => { async_complete(ret); }
-        );
+        this.local_account.open_async.begin(null, this.async_completion);
         this.local_account.open_async.end(async_result());
     }
 
     public override void tear_down() throws GLib.Error {
-        this.local_account.close_async.begin(
-            null,
-            (obj, ret) => { async_complete(ret); }
-        );
+        this.local_account.close_async.begin(null, this.async_completion);
         this.local_account.close_async.end(async_result());
         this.local_account = null;
         this.config = null;
diff --git a/test/engine/imap/transport/imap-client-connection-test.vala b/test/engine/imap/transport/imap-client-connection-test.vala
index c98f0dc5..cbbf9a78 100644
--- a/test/engine/imap/transport/imap-client-connection-test.vala
+++ b/test/engine/imap/transport/imap-client-connection-test.vala
@@ -40,13 +40,13 @@ class Geary.Imap.ClientConnectionTest : TestCase {
     public void connect_disconnect() throws GLib.Error {
         var test_article = new ClientConnection(new_endpoint());
 
-        test_article.connect_async.begin(null, this.async_complete_full);
+        test_article.connect_async.begin(null, this.async_completion);
         test_article.connect_async.end(async_result());
 
         assert_non_null(test_article.get_remote_address());
         assert_non_null(test_article.get_local_address());
 
-        test_article.disconnect_async.begin(null, this.async_complete_full);
+        test_article.disconnect_async.begin(null, this.async_completion);
         test_article.disconnect_async.end(async_result());
 
         assert_null(test_article.get_remote_address());
@@ -71,7 +71,7 @@ class Geary.Imap.ClientConnectionTest : TestCase {
         var test_article = new ClientConnection(
             new_endpoint(), COMMAND_TIMEOUT, IDLE_TIMEOUT
         );
-        test_article.connect_async.begin(null, this.async_complete_full);
+        test_article.connect_async.begin(null, this.async_completion);
         test_article.connect_async.end(async_result());
 
         assert_false(test_article.is_in_idle(), "Initial idle state");
@@ -98,12 +98,12 @@ class Geary.Imap.ClientConnectionTest : TestCase {
 
         var command = new TestCommand();
         test_article.send_command(command);
-        command.wait_until_complete.begin(null, this.async_complete_full);
+        command.wait_until_complete.begin(null, this.async_completion);
         command.wait_until_complete.end(async_result());
 
         assert_false(test_article.is_in_idle(), "Post test command");
 
-        test_article.disconnect_async.begin(null, this.async_complete_full);
+        test_article.disconnect_async.begin(null, this.async_completion);
         test_article.disconnect_async.end(async_result());
 
         TestServer.Result result = this.server.wait_for_script(this.main_loop);
@@ -126,7 +126,7 @@ class Geary.Imap.ClientConnectionTest : TestCase {
         var test_article = new ClientConnection(new_endpoint(), TIMEOUT);
         test_article.sent_command.connect(() => { sent = true; });
         test_article.receive_failure.connect(() => { recv_fail = true; });
-        test_article.connect_async.begin(null, this.async_complete_full);
+        test_article.connect_async.begin(null, this.async_completion);
         test_article.connect_async.end(async_result());
 
         var command = new TestCommand();
@@ -140,7 +140,7 @@ class Geary.Imap.ClientConnectionTest : TestCase {
             this.main_loop.iteration(false);
         }
 
-        test_article.disconnect_async.begin(null, this.async_complete_full);
+        test_article.disconnect_async.begin(null, this.async_completion);
         test_article.disconnect_async.end(async_result());
 
         assert_true(sent, "connection.sent_command");
diff --git a/test/engine/imap/transport/imap-client-session-test.vala b/test/engine/imap/transport/imap-client-session-test.vala
index 7ff91357..8e2195a8 100644
--- a/test/engine/imap/transport/imap-client-session-test.vala
+++ b/test/engine/imap/transport/imap-client-session-test.vala
@@ -47,12 +47,12 @@ class Geary.Imap.ClientSessionTest : TestCase {
         assert_true(test_article.get_protocol_state() == NOT_CONNECTED);
 
         test_article.connect_async.begin(
-            CONNECT_TIMEOUT, null, this.async_complete_full
+            CONNECT_TIMEOUT, null, this.async_completion
         );
         test_article.connect_async.end(async_result());
         assert_true(test_article.get_protocol_state() == UNAUTHORIZED);
 
-        test_article.disconnect_async.begin(null, this.async_complete_full);
+        test_article.disconnect_async.begin(null, this.async_completion);
         test_article.disconnect_async.end(async_result());
         assert_true(test_article.get_protocol_state() == NOT_CONNECTED);
 
@@ -71,13 +71,13 @@ class Geary.Imap.ClientSessionTest : TestCase {
 
         var test_article = new ClientSession(new_endpoint());
         test_article.connect_async.begin(
-            CONNECT_TIMEOUT, null, this.async_complete_full
+            CONNECT_TIMEOUT, null, this.async_completion
         );
         test_article.connect_async.end(async_result());
 
         assert_true(test_article.capabilities.supports_imap4rev1());
 
-        test_article.disconnect_async.begin(null, this.async_complete_full);
+        test_article.disconnect_async.begin(null, this.async_completion);
         test_article.disconnect_async.end(async_result());
 
         TestServer.Result result = this.server.wait_for_script(this.main_loop);
@@ -92,7 +92,7 @@ class Geary.Imap.ClientSessionTest : TestCase {
         GLib.Timer timer = new GLib.Timer();
         timer.start();
         test_article.connect_async.begin(
-            CONNECT_TIMEOUT, null, this.async_complete_full
+            CONNECT_TIMEOUT, null, this.async_completion
         );
         try {
             test_article.connect_async.end(async_result());
@@ -117,19 +117,19 @@ class Geary.Imap.ClientSessionTest : TestCase {
 
         var test_article = new ClientSession(new_endpoint());
         test_article.connect_async.begin(
-            CONNECT_TIMEOUT, null, this.async_complete_full
+            CONNECT_TIMEOUT, null, this.async_completion
         );
         test_article.connect_async.end(async_result());
         test_article.login_async.begin(
             new Credentials(PASSWORD, "test", "password"),
             null,
-            this.async_complete_full
+            this.async_completion
         );
         test_article.login_async.end(async_result());
 
         assert_true(test_article.capabilities.supports_imap4rev1());
 
-        test_article.disconnect_async.begin(null, this.async_complete_full);
+        test_article.disconnect_async.begin(null, this.async_completion);
         test_article.disconnect_async.end(async_result());
 
         TestServer.Result result = this.server.wait_for_script(this.main_loop);
@@ -151,7 +151,7 @@ class Geary.Imap.ClientSessionTest : TestCase {
         assert_true(test_article.get_protocol_state() == NOT_CONNECTED);
 
         test_article.connect_async.begin(
-            CONNECT_TIMEOUT, null, this.async_complete_full
+            CONNECT_TIMEOUT, null, this.async_completion
         );
         test_article.connect_async.end(async_result());
         assert_true(test_article.get_protocol_state() == UNAUTHORIZED);
@@ -159,12 +159,12 @@ class Geary.Imap.ClientSessionTest : TestCase {
         test_article.login_async.begin(
             new Credentials(PASSWORD, "test", "password"),
             null,
-            this.async_complete_full
+            this.async_completion
         );
         test_article.login_async.end(async_result());
         assert_true(test_article.get_protocol_state() == AUTHORIZED);
 
-        test_article.disconnect_async.begin(null, this.async_complete_full);
+        test_article.disconnect_async.begin(null, this.async_completion);
         test_article.disconnect_async.end(async_result());
         assert_true(test_article.get_protocol_state() == NOT_CONNECTED);
 
@@ -188,12 +188,12 @@ class Geary.Imap.ClientSessionTest : TestCase {
         assert_true(test_article.get_protocol_state() == NOT_CONNECTED);
 
         test_article.connect_async.begin(
-            CONNECT_TIMEOUT, null, this.async_complete_full
+            CONNECT_TIMEOUT, null, this.async_completion
         );
         test_article.connect_async.end(async_result());
         assert_true(test_article.get_protocol_state() == UNAUTHORIZED);
 
-        test_article.logout_async.begin(null, this.async_complete_full);
+        test_article.logout_async.begin(null, this.async_completion);
         test_article.logout_async.end(async_result());
         assert_true(test_article.get_protocol_state() == NOT_CONNECTED);
 
@@ -219,7 +219,7 @@ class Geary.Imap.ClientSessionTest : TestCase {
         assert_true(test_article.get_protocol_state() == NOT_CONNECTED);
 
         test_article.connect_async.begin(
-            CONNECT_TIMEOUT, null, this.async_complete_full
+            CONNECT_TIMEOUT, null, this.async_completion
         );
         test_article.connect_async.end(async_result());
         assert_true(test_article.get_protocol_state() == UNAUTHORIZED);
@@ -227,12 +227,12 @@ class Geary.Imap.ClientSessionTest : TestCase {
         test_article.login_async.begin(
             new Credentials(PASSWORD, "test", "password"),
             null,
-            this.async_complete_full
+            this.async_completion
         );
         test_article.login_async.end(async_result());
         assert_true(test_article.get_protocol_state() == AUTHORIZED);
 
-        test_article.logout_async.begin(null, this.async_complete_full);
+        test_article.logout_async.begin(null, this.async_completion);
         test_article.logout_async.end(async_result());
         assert_true(test_article.get_protocol_state() == NOT_CONNECTED);
 
@@ -264,7 +264,7 @@ class Geary.Imap.ClientSessionTest : TestCase {
         assert_true(test_article.get_protocol_state() == NOT_CONNECTED);
 
         test_article.connect_async.begin(
-            CONNECT_TIMEOUT, null, this.async_complete_full
+            CONNECT_TIMEOUT, null, this.async_completion
         );
         test_article.connect_async.end(async_result());
         assert_true(test_article.get_protocol_state() == UNAUTHORIZED);
@@ -272,7 +272,7 @@ class Geary.Imap.ClientSessionTest : TestCase {
         test_article.initiate_session_async.begin(
             new Credentials(PASSWORD, "test", "password"),
             null,
-            this.async_complete_full
+            this.async_completion
         );
         test_article.initiate_session_async.end(async_result());
 
@@ -283,7 +283,7 @@ class Geary.Imap.ClientSessionTest : TestCase {
         assert_string("Inbox", test_article.inbox.mailbox.name);
         assert_true(test_article.inbox.mailbox.is_inbox);
 
-        test_article.disconnect_async.begin(null, this.async_complete_full);
+        test_article.disconnect_async.begin(null, this.async_completion);
         test_article.disconnect_async.end(async_result());
 
         TestServer.Result result = this.server.wait_for_script(this.main_loop);
@@ -308,7 +308,7 @@ class Geary.Imap.ClientSessionTest : TestCase {
         assert_true(test_article.get_protocol_state() == NOT_CONNECTED);
 
         test_article.connect_async.begin(
-            CONNECT_TIMEOUT, null, this.async_complete_full
+            CONNECT_TIMEOUT, null, this.async_completion
         );
         test_article.connect_async.end(async_result());
         assert_true(test_article.get_protocol_state() == UNAUTHORIZED);
@@ -316,7 +316,7 @@ class Geary.Imap.ClientSessionTest : TestCase {
         test_article.initiate_session_async.begin(
             new Credentials(PASSWORD, "test", "password"),
             null,
-            this.async_complete_full
+            this.async_completion
         );
         test_article.initiate_session_async.end(async_result());
 
@@ -327,7 +327,7 @@ class Geary.Imap.ClientSessionTest : TestCase {
         assert_string("Inbox", test_article.inbox.mailbox.name);
         assert_true(test_article.inbox.mailbox.is_inbox);
 
-        test_article.disconnect_async.begin(null, this.async_complete_full);
+        test_article.disconnect_async.begin(null, this.async_completion);
         test_article.disconnect_async.end(async_result());
 
         TestServer.Result result = this.server.wait_for_script(this.main_loop);
@@ -371,7 +371,7 @@ class Geary.Imap.ClientSessionTest : TestCase {
         assert_true(test_article.get_protocol_state() == NOT_CONNECTED);
 
         test_article.connect_async.begin(
-            CONNECT_TIMEOUT, null, this.async_complete_full
+            CONNECT_TIMEOUT, null, this.async_completion
         );
         test_article.connect_async.end(async_result());
         assert_true(test_article.get_protocol_state() == UNAUTHORIZED);
@@ -379,7 +379,7 @@ class Geary.Imap.ClientSessionTest : TestCase {
         test_article.initiate_session_async.begin(
             new Credentials(PASSWORD, "test", "password"),
             null,
-            this.async_complete_full
+            this.async_completion
         );
         test_article.initiate_session_async.end(async_result());
 
@@ -398,7 +398,7 @@ class Geary.Imap.ClientSessionTest : TestCase {
             "user.", test_article.get_other_users_namespaces()[0].prefix
         );
 
-        test_article.disconnect_async.begin(null, this.async_complete_full);
+        test_article.disconnect_async.begin(null, this.async_completion);
         test_article.disconnect_async.end(async_result());
 
         TestServer.Result result = this.server.wait_for_script(this.main_loop);
diff --git a/test/engine/imap/transport/imap-deserializer-test.vala b/test/engine/imap/transport/imap-deserializer-test.vala
index f090057e..0759025a 100644
--- a/test/engine/imap/transport/imap-deserializer-test.vala
+++ b/test/engine/imap/transport/imap-deserializer-test.vala
@@ -51,7 +51,7 @@ class Geary.Imap.DeserializerTest : TestCase {
     }
 
     public override void tear_down() {
-        this.deser.stop_async.begin((obj, ret) => { async_complete(ret); });
+        this.deser.stop_async.begin(this.async_completion);
         async_result();
         this.stream = null;
     }
@@ -62,7 +62,7 @@ class Geary.Imap.DeserializerTest : TestCase {
         this.stream.add_data(bytes.data);
         this.stream.add_data(EOL.data);
 
-        this.process.begin(Expect.MESSAGE, (obj, ret) => { async_complete(ret); });
+        this.process.begin(Expect.MESSAGE, this.async_completion);
         RootParameters? message = this.process.end(async_result());
 
         assert_int(2, message.size);
@@ -76,7 +76,7 @@ class Geary.Imap.DeserializerTest : TestCase {
         this.stream.add_data(bytes.data);
         this.stream.add_data(EOL.data);
 
-        this.process.begin(Expect.MESSAGE, (obj, ret) => { async_complete(ret); });
+        this.process.begin(Expect.MESSAGE, this.async_completion);
         RootParameters? message = this.process.end(async_result());
 
         assert_int(2, message.size);
@@ -90,7 +90,7 @@ class Geary.Imap.DeserializerTest : TestCase {
         this.stream.add_data(bytes.data);
         this.stream.add_data(EOL.data);
 
-        this.process.begin(Expect.MESSAGE, (obj, ret) => { async_complete(ret); });
+        this.process.begin(Expect.MESSAGE, this.async_completion);
         RootParameters? message = this.process.end(async_result());
 
         assert_int(2, message.size);
@@ -104,7 +104,7 @@ class Geary.Imap.DeserializerTest : TestCase {
         this.stream.add_data(bytes.data);
         this.stream.add_data(EOL.data);
 
-        this.process.begin(Expect.MESSAGE, (obj, ret) => { async_complete(ret); });
+        this.process.begin(Expect.MESSAGE, this.async_completion);
         RootParameters? message = this.process.end(async_result());
 
         assert_int(2, message.size);
@@ -118,7 +118,7 @@ class Geary.Imap.DeserializerTest : TestCase {
         this.stream.add_data(bytes.data);
         this.stream.add_data(EOL.data);
 
-        this.process.begin(Expect.MESSAGE, (obj, ret) => { async_complete(ret); });
+        this.process.begin(Expect.MESSAGE, this.async_completion);
         RootParameters? message = this.process.end(async_result());
 
         assert_int(2, message.size);
@@ -136,7 +136,7 @@ class Geary.Imap.DeserializerTest : TestCase {
         // deserializer currently silently ignores lines with
         // malformed lists and continues parsing, so we get to the end
         // of the stream.
-        this.process.begin(Expect.EOS, (obj, ret) => { async_complete(ret); });
+        this.process.begin(Expect.EOS, this.async_completion);
         this.process.end(async_result());
     }
 
@@ -150,7 +150,7 @@ class Geary.Imap.DeserializerTest : TestCase {
         // deserializer currently silently ignores lines with
         // malformed lists and continues parsing, so we get to the end
         // of the stream.
-        this.process.begin(Expect.EOS, (obj, ret) => { async_complete(ret); });
+        this.process.begin(Expect.EOS, this.async_completion);
         this.process.end(async_result());
     }
 
@@ -159,7 +159,7 @@ class Geary.Imap.DeserializerTest : TestCase {
         this.stream.add_data(greeting.data);
         this.stream.add_data(EOL.data);
 
-        this.process.begin(Expect.MESSAGE, (obj, ret) => { async_complete(ret); });
+        this.process.begin(Expect.MESSAGE, this.async_completion);
         RootParameters? message = this.process.end(async_result());
 
         assert(message.to_string() == greeting);
@@ -170,7 +170,7 @@ class Geary.Imap.DeserializerTest : TestCase {
         this.stream.add_data(greeting.data);
         this.stream.add_data(EOL.data);
 
-        this.process.begin(Expect.MESSAGE, (obj, ret) => { async_complete(ret); });
+        this.process.begin(Expect.MESSAGE, this.async_completion);
         RootParameters? message = this.process.end(async_result());
 
         assert(message.to_string() == greeting);
@@ -182,7 +182,7 @@ class Geary.Imap.DeserializerTest : TestCase {
         this.stream.add_data(greeting.data);
         this.stream.add_data(EOL.data);
 
-        this.process.begin(Expect.MESSAGE, (obj, ret) => { async_complete(ret); });
+        this.process.begin(Expect.MESSAGE, this.async_completion);
         RootParameters? message = this.process.end(async_result());
 
         assert(message.to_string() == parsed);
@@ -193,7 +193,7 @@ class Geary.Imap.DeserializerTest : TestCase {
         this.stream.add_data(flags.data);
         this.stream.add_data(EOL.data);
 
-        this.process.begin(Expect.DESER_FAIL, (obj, ret) => { async_complete(ret); });
+        this.process.begin(Expect.DESER_FAIL, this.async_completion);
         this.process.end(async_result());
     }
 
@@ -202,7 +202,7 @@ class Geary.Imap.DeserializerTest : TestCase {
         this.stream.add_data(flags.data);
         this.stream.add_data(EOL.data);
 
-        this.process.begin(Expect.MESSAGE, (obj, ret) => { async_complete(ret); });
+        this.process.begin(Expect.MESSAGE, this.async_completion);
         RootParameters? message = this.process.end(async_result());
 
         assert(message.to_string() == flags);
@@ -213,7 +213,7 @@ class Geary.Imap.DeserializerTest : TestCase {
         this.stream.add_data(flags.data);
         this.stream.add_data(EOL.data);
 
-        this.process.begin(Expect.MESSAGE, (obj, ret) => { async_complete(ret); });
+        this.process.begin(Expect.MESSAGE, this.async_completion);
         RootParameters? message = this.process.end(async_result());
 
         assert(message.to_string() == flags);
@@ -224,7 +224,7 @@ class Geary.Imap.DeserializerTest : TestCase {
         this.stream.add_data(flags.data);
         this.stream.add_data(EOL.data);
 
-        this.process.begin(Expect.MESSAGE, (obj, ret) => { async_complete(ret); });
+        this.process.begin(Expect.MESSAGE, this.async_completion);
         RootParameters? message = this.process.end(async_result());
 
         assert(message.to_string() == flags);
@@ -239,7 +239,7 @@ class Geary.Imap.DeserializerTest : TestCase {
         this.stream.add_data(flags.data);
         this.stream.add_data(EOL.data);
 
-        this.process.begin(Expect.MESSAGE, (obj, ret) => { async_complete(ret); });
+        this.process.begin(Expect.MESSAGE, this.async_completion);
         RootParameters? message = this.process.end(async_result());
 
         assert(message.to_string() == expected);
@@ -250,12 +250,12 @@ class Geary.Imap.DeserializerTest : TestCase {
         this.stream.add_data(flags.data);
         this.stream.add_data(EOL.data);
 
-        this.process.begin(Expect.DESER_FAIL, (obj, ret) => { async_complete(ret); });
+        this.process.begin(Expect.DESER_FAIL, this.async_completion);
         this.process.end(async_result());
     }
 
     public void instant_eos() throws Error {
-        this.process.begin(Expect.EOS, (obj, ret) => { async_complete(ret); });
+        this.process.begin(Expect.EOS, this.async_completion);
         this.process.end(async_result());
         assert(this.deser.is_halted());
     }
@@ -267,7 +267,7 @@ class Geary.Imap.DeserializerTest : TestCase {
         bool eos = false;
         this.deser.end_of_stream.connect(() => { eos = true; });
 
-        this.process.begin(Expect.MESSAGE, (obj, ret) => { async_complete(ret); });
+        this.process.begin(Expect.MESSAGE, this.async_completion);
         RootParameters? message = this.process.end(async_result());
         assert(message.to_string() == bye);
         assert(eos);
diff --git a/test/engine/rfc822-message-test.vala b/test/engine/rfc822-message-test.vala
index 2f1ab3f9..cc3f0a40 100644
--- a/test/engine/rfc822-message-test.vala
+++ b/test/engine/rfc822-message-test.vala
@@ -231,7 +231,7 @@ This is the second line.
 
         this.message_from_composed_email.begin(
             composed,
-            async_complete_full
+            this.async_completion
         );
         Geary.RFC822.Message message = message_from_composed_email.end(async_result());
 
@@ -261,7 +261,7 @@ This is the second line.
 
         this.message_from_composed_email.begin(
             composed,
-            async_complete_full
+            this.async_completion
         );
         Geary.RFC822.Message message = message_from_composed_email.end(async_result());
 
@@ -286,7 +286,7 @@ This is the second line.
 
         this.message_from_composed_email.begin(
             composed,
-            async_complete_full
+            this.async_completion
         );
         Geary.RFC822.Message message = message_from_composed_email.end(async_result());
 
@@ -343,7 +343,7 @@ This is the second line.
 
         this.message_from_composed_email.begin(
             composed,
-            async_complete_full
+            this.async_completion
         );
         Geary.RFC822.Message message = message_from_composed_email.end(async_result());
 
diff --git a/test/engine/rfc822-utils-test.vala b/test/engine/rfc822-utils-test.vala
index d150b71f..1691fa41 100644
--- a/test/engine/rfc822-utils-test.vala
+++ b/test/engine/rfc822-utils-test.vala
@@ -27,7 +27,7 @@ class Geary.RFC822.Utils.Test : TestCase {
     public void best_encoding_default() throws GLib.Error {
         string test = "abc";
         var stream = new GMime.StreamMem.with_buffer(test.data);
-        get_best_encoding.begin(stream, 7BIT, null, async_complete_full);
+        get_best_encoding.begin(stream, 7BIT, null, this.async_completion);
         var encoding = get_best_encoding.end(async_result());
         assert_true(encoding == DEFAULT);
     }
@@ -38,7 +38,7 @@ class Geary.RFC822.Utils.Test : TestCase {
             buf.append("long ");
         }
         var stream = new GMime.StreamMem.with_buffer(buf.str.data);
-        get_best_encoding.begin(stream, 7BIT, null, async_complete_full);
+        get_best_encoding.begin(stream, 7BIT, null, this.async_completion);
         var encoding = get_best_encoding.end(async_result());
         assert_true(encoding == QUOTEDPRINTABLE);
     }
@@ -46,7 +46,7 @@ class Geary.RFC822.Utils.Test : TestCase {
     public void best_encoding_binary() throws GLib.Error {
         uint8 test[] = { 0x20, 0x00, 0x20 };
         var stream = new GMime.StreamMem.with_buffer(test);
-        get_best_encoding.begin(stream, 7BIT, null, async_complete_full);
+        get_best_encoding.begin(stream, 7BIT, null, this.async_completion);
         var encoding = get_best_encoding.end(async_result());
         assert_true(encoding == BASE64);
     }
diff --git a/test/integration/imap/client-session.vala b/test/integration/imap/client-session.vala
index f6221f63..d4f1c3d8 100644
--- a/test/integration/imap/client-session.vala
+++ b/test/integration/imap/client-session.vala
@@ -34,17 +34,17 @@ class Integration.Imap.ClientSession : TestCase {
 
     public override void tear_down() throws GLib.Error {
         if (this.session.get_protocol_state() != NOT_CONNECTED) {
-            this.session.disconnect_async.begin(null, async_complete_full);
+            this.session.disconnect_async.begin(null, this.async_completion);
             this.session.disconnect_async.end(async_result());
         }
         this.session = null;
     }
 
     public void session_connect() throws GLib.Error {
-        this.session.connect_async.begin(2, null, async_complete_full);
+        this.session.connect_async.begin(2, null, this.async_completion);
         this.session.connect_async.end(async_result());
 
-        this.session.disconnect_async.begin(null, async_complete_full);
+        this.session.disconnect_async.begin(null, this.async_completion);
         this.session.disconnect_async.end(async_result());
     }
 
@@ -55,7 +55,7 @@ class Integration.Imap.ClientSession : TestCase {
             PASSWORD, "automated-integration-test", "password"
         );
         this.session.login_async.begin(
-            password_creds, null, async_complete_full
+            password_creds, null, this.async_completion
         );
         try {
             this.session.login_async.end(async_result());
@@ -78,7 +78,7 @@ class Integration.Imap.ClientSession : TestCase {
             OAUTH2, "automated-integration-test", "password"
         );
         this.session.login_async.begin(
-            oauth2_creds, null, async_complete_full
+            oauth2_creds, null, this.async_completion
         );
         try {
             this.session.login_async.end(async_result());
@@ -92,13 +92,13 @@ class Integration.Imap.ClientSession : TestCase {
         do_connect();
 
         this.session.initiate_session_async.begin(
-            this.config.credentials, null, async_complete_full
+            this.config.credentials, null, this.async_completion
         );
         this.session.initiate_session_async.end(async_result());
     }
 
     private void do_connect() throws GLib.Error {
-        this.session.connect_async.begin(5, null, async_complete_full);
+        this.session.connect_async.begin(5, null, this.async_completion);
         this.session.connect_async.end(async_result());
     }
 
diff --git a/test/integration/smtp/client-session.vala b/test/integration/smtp/client-session.vala
index 30b03eb4..b6c0c801 100644
--- a/test/integration/smtp/client-session.vala
+++ b/test/integration/smtp/client-session.vala
@@ -37,7 +37,7 @@ class Integration.Smtp.ClientSession : TestCase {
 
     public override void tear_down() throws GLib.Error {
         try {
-            this.session.logout_async.begin(false, null, async_complete_full);
+            this.session.logout_async.begin(false, null, this.async_completion);
             this.session.logout_async.end(async_result());
         } catch (GLib.Error err) {
             // Oh well
@@ -52,7 +52,7 @@ class Integration.Smtp.ClientSession : TestCase {
             "deliberately-invalid-password"
         );
         this.session.login_async.begin(
-            password_creds, null, async_complete_full
+            password_creds, null, this.async_completion
         );
         try {
             this.session.login_async.end(async_result());
@@ -69,7 +69,7 @@ class Integration.Smtp.ClientSession : TestCase {
             "deliberately-invalid-token"
         );
         this.session.login_async.begin(
-            oauth2_creds, null, async_complete_full
+            oauth2_creds, null, this.async_completion
         );
         try {
             this.session.login_async.end(async_result());
@@ -97,7 +97,7 @@ class Integration.Smtp.ClientSession : TestCase {
                 "Geary integration test",
                 this.config.credentials.user
             ),
-            async_complete_full
+            this.async_completion
         );
         Geary.RFC822.Message message = new_message.end(async_result());
 
@@ -105,14 +105,14 @@ class Integration.Smtp.ClientSession : TestCase {
             return_path,
             message,
             null,
-            async_complete_full
+            this.async_completion
         );
         this.session.send_email_async.end(async_result());
     }
 
     private void do_connect() throws GLib.Error {
         this.session.login_async.begin(
-            this.config.credentials, null, async_complete_full
+            this.config.credentials, null, this.async_completion
         );
         this.session.login_async.end(async_result());
     }
diff --git a/test/test-case.vala b/test/test-case.vala
index 901be037..b9c78720 100644
--- a/test/test-case.vala
+++ b/test/test-case.vala
@@ -360,17 +360,8 @@ public abstract class TestCase : GLib.Object {
      *
      * @see AsyncResultWaiter.async_completion
      */
-    protected void async_complete(AsyncResult result) {
-        this.async_waiter.async_completion(null, result);
-    }
-
-    /**
-     * Calls the same method on the test case's default async waiter.
-     *
-     * @see AsyncResultWaiter.async_completion
-     */
-    protected void async_complete_full(GLib.Object? object,
-                                       AsyncResult result) {
+    protected void async_completion(GLib.Object? object,
+                                    AsyncResult result) {
         this.async_waiter.async_completion(object, result);
     }