Add a unit test for upgrading an actual Geary v0.6 database.

src/engine/db/db-versioned-database.vala

@@ -42,6 +42,12 @@ public class Geary.Db.VersionedDatabase : Geary.Db.Database {
         this.schema_dir = schema_dir;
     }
 
+    /** Returns the current schema version number of this database. */
+    public int get_schema_version()
+        throws GLib.Error {
+        return get_master_connection().get_user_version_number();
+    }
+
     /**
      * Called by {@link open} if a schema upgrade is required and beginning.
      *

test/data/org.gnome.GearyTest.gresource.xml

@@ -4,5 +4,6 @@
     <file>basic-text-plain.eml</file>
     <file>basic-text-html.eml</file>
     <file>basic-multipart-alternative.eml</file>
+    <file>geary-0.6-db.tar.xz</file>
   </gresource>
 </gresources>

test/engine/imap-db/imap-db-database-test.vala

@@ -12,6 +12,7 @@ class Geary.ImapDB.DatabaseTest : TestCase {
     public DatabaseTest() {
         base("Geary.ImapDb.DatabaseTest");
         add_test("open_new", open_new);
+        add_test("upgrade_0_6", upgrade_0_6);
     }
 
     public void open_new() throws Error {
@@ -45,5 +46,113 @@ class Geary.ImapDB.DatabaseTest : TestCase {
         tmp_dir.delete();
     }
 
+    public void upgrade_0_6() throws Error {
+        GLib.File tmp_dir = GLib.File.new_for_path(
+            GLib.DirUtils.make_tmp("geary-db-database-test-XXXXXX")
+        );
+
+        // Since the upgrade process also messes around with
+        // attachments on disk which we want to be able to test, we
+        // need to have a complete-ish database and attachments
+        // directory hierarchy. For convenience, these are included as
+        // a single compressed archive, but that means we need to
+        // un-compress and unpack the archive as part of the test
+        // fixture.
+        const string DB_0_6_RESOURCE = "geary-0.6-db.tar.xz";
+        const string DB_0_6_DIR = "geary-0.6-db";
+        const string ATTACHMENT_12 = "capitalism.jpeg";
+
+        GLib.File db_archive = GLib.File
+            .new_for_uri(RESOURCE_URI)
+            .resolve_relative_path(DB_0_6_RESOURCE);
+        GLib.File db_dir = tmp_dir.get_child(DB_0_6_DIR);
+        GLib.File db_file = db_dir.get_child("geary.db");
+        GLib.File attachments_dir = db_dir.get_child("attachments");
+
+        unpack_archive(db_archive, tmp_dir);
+
+        // This number is the id of the last known message in the
+        // database
+        GLib.File message_dir = attachments_dir.get_child("43");
+
+        // Ensure one of the expected attachments exists up
+        // front. Since there are 12 known attachments, 12 should be
+        // the last one in the table and exist on the file system,
+        // while 13 should not.
+        assert_true(
+            message_dir.get_child("12").get_child(ATTACHMENT_12).query_exists(),
+            "Expected attachment file"
+        );
+        assert_false(
+            message_dir.get_child("13").query_exists(),
+            "Unexpected attachment file"
+        );
+
+        Database db = new Database(
+            db_file,
+            GLib.File.new_for_path(_SOURCE_ROOT_DIR).get_child("sql"),
+            attachments_dir,
+            new Geary.SimpleProgressMonitor(Geary.ProgressType.DB_UPGRADE),
+            new Geary.SimpleProgressMonitor(Geary.ProgressType.DB_VACUUM),
+            "test@example.com"
+        );
+
+        db.open.begin(
+            Geary.Db.DatabaseFlags.CREATE_FILE, null,
+            (obj, ret) => { async_complete(ret); }
+        );
+        db.open.end(async_result());
+
+        assert_int(25, db.get_schema_version(), "Post-upgrade version");
+
+        // Since schema v22 deletes the re-creates all attachments,
+        // attachment 12 should no longer exist on the file system and
+        // there should be an attachment with id 24.
+        assert_false(
+            message_dir.get_child("12").get_child(ATTACHMENT_12).query_exists(),
+            "Old attachment file not deleted"
+        );
+        assert_true(
+            message_dir.get_child("24").get_child(ATTACHMENT_12).query_exists(),
+            "New attachment dir/file not created"
+        );
+
+
+        // Need to close it again to stop the GC process running
+        db.close();
+
+        Geary.Files.recursive_delete_async.begin(
+            tmp_dir, null,
+            (obj, res) => { async_complete(res); }
+        );
+        Geary.Files.recursive_delete_async.end(async_result());
+    }
+
+
+    private void unpack_archive(GLib.File archive, GLib.File dest)
+        throws Error {
+        // GLib doesn't seem to have native support for unpacking
+        // multi-file archives however, so use this fun kludge
+        // instead.
+
+        GLib.InputStream bytes = archive.read();
+
+        GLib.Subprocess untar = new GLib.Subprocess(
+            GLib.SubprocessFlags.STDIN_PIPE,
+            "tar", "-xJf", "-", "-C", dest.get_path()
+        );
+        GLib.OutputStream stdin = untar.get_stdin_pipe();
+
+        uint8[] buf = new uint8[4096];
+        ssize_t len = 0;
+        do {
+            len = bytes.read(buf);
+            stdin.write(buf[0:len]);
+        } while (len > 0);
+
+        stdin.close();
+
+        untar.wait();
+    }
 
 }