Update Meson build to also build separate engine and client tests.

* src/engine/meson.build: Add some ugly hacks to both build the internal
  VAPI and work around a valac bug to ensure the internal VAPI correctly
  references the internal header, not the public header.

* test/meson.build: Split the test suite build into test-engine and
  test-client.

src/engine/meson.build

@@ -331,12 +331,27 @@ geary_engine_dependencies = [
   sqlite
 ]
 
+geary_engine_vala_options = geary_vala_options
+geary_engine_vala_options += [
+  # Nasty hack to make sure engine internal VAPI is generated. See
+  # Meson issue https://github.com/mesonbuild/meson/issues/1781 for
+  # official internal VAPI support. See Vala Bug 731322 about the
+  # specifics of the arguments used below to generate the internal
+  # VAPI. In paricular, the filenames needs to not contain any paths
+  # or else the internal vapi will use the public header, not the
+  # internal header. Of course these paths breaks the build, so we fix
+  # it up using cp below.
+  '--header=geary-engine.h',
+  '--internal-vapi=geary-engine-internal.vapi',
+  '--internal-header=geary-engine-internal.h'
+]
+
 geary_engine_lib = static_library('geary-engine',
   geary_engine_sources,
   dependencies: geary_engine_dependencies,
   link_with: sqlite3_unicodesn_lib,
   include_directories: config_h_dir,
-  vala_args: geary_vala_options,
+  vala_args: geary_engine_vala_options,
   c_args: geary_c_options,
 )
 
@@ -347,3 +362,34 @@ geary_engine_dep = declare_dependency(
   ],
   include_directories: include_directories('.'),
 )
+
+# Dummy target to fix the location of the public and internal headers,
+# and tell Meson about the internal VAPI
+geary_engine_internal_vapi = custom_target(
+  'geary-engine-internal-vapi',
+  output: ['geary-engine-internal.vapi'],
+  command: [
+    find_program('cp'),
+    'geary-engine.h',
+    'geary-engine-internal.h',
+    '@OUTDIR@/geary-engine@sta/geary-engine-internal.vapi',
+    '@OUTDIR@',
+  ],
+  depends: geary_engine_lib
+)
+
+geary_engine_internal_dep = declare_dependency(
+  # Can't just include geary_engine_lib in link_with since that will
+  # pull in the public header and we get duplicate symbol errors.
+  link_args: [
+    '-L' + meson.build_root() + '/src/engine',
+    '-lgeary-engine'
+  ],
+  link_with: [
+    sqlite3_unicodesn_lib,
+  ],
+  include_directories: include_directories('.'),
+  sources: [
+    geary_engine_internal_vapi
+  ],
+)

test/meson.build

@@ -1,9 +1,14 @@
-geary_test_sources = [
-  'main.vala',
-  'testcase.vala', # Based on same file in libgee, courtesy Julien Peeters
+geary_test_engine_sources = [
+  'test-engine.vala',
+  'testcase.vala',
 
   'engine/api/geary-attachment-test.vala',
   'engine/api/geary-engine-test.vala',
+  'engine/api/geary-email-identifier-test.vala',
+  'engine/api/geary-folder-test.vala',
+  'engine/api/geary-folder-path-test.vala',
+  'engine/app/app-conversation-test.vala',
+  'engine/app/app-conversation-set-test.vala',
   'engine/imap/command/imap-create-command-test.vala',
   'engine/imap/response/imap-namespace-response-test.vala',
   'engine/imap/transport/imap-deserializer-test.vala',
@@ -16,7 +21,12 @@ geary_test_sources = [
   'engine/util-idle-manager-test.vala',
   'engine/util-inet-test.vala',
   'engine/util-js-test.vala',
-  'engine/util-timeout-manager-test.vala',
+  'engine/util-timeout-manager-test.vala'
+]
+
+geary_test_client_sources = [
+  'test-client.vala',
+  'testcase.vala',
 
   'client/application/geary-configuration-test.vala',
   'client/components/client-web-view-test.vala',
@@ -26,25 +36,48 @@ geary_test_sources = [
   'js/client-page-state-test.vala',
   'js/composer-page-state-test.vala',
   'js/conversation-page-state-test.vala',
+
   geary_compiled_schema,
   geary_resources
 ]
 
-geary_test_dependencies = [
+geary_test_engine_dependencies = [
+  geary_engine_internal_dep,
   gee,
-  gtk,
-  libsoup,
+  gio,
+  glib,
   gmime,
-  webkit2gtk,
-  geary_engine_dep,
-  geary_client_dep,
+  javascriptcoregtk,
+  libunwind,
+  libxml,
+  sqlite,
 ]
 
-geary_test_bin = executable('geary-test',
-  geary_test_sources,
-  dependencies: geary_test_dependencies,
+geary_test_client_dependencies = [
+  geary_client_dep,
+  geary_engine_dep,
+  gee,
+  gmime,
+  gtk,
+  libsoup,
+  webkit2gtk,
+]
+
+geary_test_engine_bin = executable('geary-test-engine',
+  geary_test_engine_sources,
+  dependencies: geary_test_engine_dependencies,
   include_directories: config_h_dir,
   vala_args: geary_vala_options,
   c_args: geary_c_options,
 )
-test('Geary test suite', geary_test_bin)
+
+geary_test_client_bin = executable('geary-test-client',
+  geary_test_client_sources,
+  dependencies: geary_test_client_dependencies,
+  include_directories: config_h_dir,
+  vala_args: geary_vala_options,
+  c_args: geary_c_options,
+)
+
+test('engine-tests', geary_test_engine_bin)
+test('client-tests', geary_test_client_bin)