test: Allow optional usage of vendored googletest

Change-Id: I7011edb826b11762f1eb49e8bbc3a19c8006f8c5
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/.clang-ignore b/.clang-ignore
new file mode 100644
index 0000000..36f17f2
--- /dev/null
+++ b/.clang-ignore
@@ -0,0 +1 @@
+./subprojects
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..025c6c9
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+/subprojects/*/
diff --git a/meson.build b/meson.build
index ae1e2c6..f23dec5 100644
--- a/meson.build
+++ b/meson.build
@@ -1,5 +1,5 @@
 project('sdeventplus', 'cpp',
-        version: '0.1', meson_version: '>=0.49.0',
+        version: '0.1', meson_version: '>=0.53.2',
         default_options: [
           'warning_level=3',
           'werror=true',
diff --git a/subprojects/googletest.wrap b/subprojects/googletest.wrap
new file mode 100644
index 0000000..fb55947
--- /dev/null
+++ b/subprojects/googletest.wrap
@@ -0,0 +1,3 @@
+[wrap-git]
+url = https://github.com/google/googletest
+revision = release-1.10.0
diff --git a/test/meson.build b/test/meson.build
index 3b8f167..e520f8b 100644
--- a/test/meson.build
+++ b/test/meson.build
@@ -1,5 +1,19 @@
-gtest = dependency('gtest', main: true, disabler: true, required: build_tests)
-gmock = dependency('gmock', disabler: true, required: build_tests)
+gtest = dependency('gtest', main: true, disabler: true, required: false)
+gmock = dependency('gmock', disabler: true, required: false)
+if not gtest.found() or not gmock.found()
+  gtest_proj = import('cmake').subproject('googletest', required: false)
+  if gtest_proj.found()
+    gtest = declare_dependency(
+      dependencies: [
+        dependency('threads'),
+        gtest_proj.dependency('gtest'),
+        gtest_proj.dependency('gtest_main'),
+      ])
+    gmock = gtest_proj.dependency('gmock')
+  else
+    assert(not build_tests.enabled(), 'Googletest is required')
+  endif
+endif
 
 tests = [
   'clock',