[flutter_plugin_tools] Make having no Java unit tests a failure (#4310)

This brings the native Android unit tests in line with the policy of having tests that we expect all plugins to have—unless there's a very specific reason to opt them out—fail when missing instead of skipping when missing, to help guard against errors where we silently fail to run tests we think we are running.

Adds an explicit exclusion list covering the plugins that have a reason to be opted out.

Android portion of #85469

.cirrus.yml

@@ -182,7 +182,8 @@ task:
         - export CIRRUS_COMMIT_MESSAGE=""
         # Native integration tests are handled by firebase-test-lab below, so
         # only run unit tests.
-        - ./script/tool_runner.sh native-test --android --no-integration  # must come after apk build
+        # Must come after build-examples.
+        - ./script/tool_runner.sh native-test --android --no-integration --exclude script/configs/exclude_native_unit_android.yaml
       firebase_test_lab_script:
         # Unsetting CIRRUS_CHANGE_MESSAGE and CIRRUS_COMMIT_MESSAGE as they
         # might include non-ASCII characters which makes Gradle crash.

script/configs/exclude_native_unit_android.yaml

@@ -0,0 +1,11 @@
+# Deprecated; no plan to backfill the missing files
+- android_alarm_manager
+- battery
+- device_info/device_info
+- package_info
+- sensors
+- share
+- wifi_info_flutter/wifi_info_flutter
+
+# No need for unit tests:
+- espresso

script/tool/CHANGELOG.md

@@ -1,3 +1,8 @@
+## NEXT
+
+- `native-test --android` now fails plugins that don't have unit tests,
+  rather than skipping them.
+
 ## 0.7.1
 
 - Add support for `.pluginToolsConfig.yaml` in the `build-examples` command.

script/tool/lib/src/native_test_command.dart

@@ -242,7 +242,8 @@ this command.
 
     final Iterable<RepositoryPackage> examples = plugin.getExamples();
 
-    bool ranTests = false;
+    bool ranUnitTests = false;
+    bool ranAnyTests = false;
     bool failed = false;
     bool hasMissingBuild = false;
     for (final RepositoryPackage example in examples) {
@@ -289,7 +290,8 @@ this command.
           printError('$exampleName unit tests failed.');
           failed = true;
         }
-        ranTests = true;
+        ranUnitTests = true;
+        ranAnyTests = true;
       }
 
       if (runIntegrationTests) {
@@ -311,7 +313,7 @@ this command.
           printError('$exampleName integration tests failed.');
           failed = true;
         }
-        ranTests = true;
+        ranAnyTests = true;
       }
     }
 
@@ -321,7 +323,12 @@ this command.
               ? 'Examples must be built before testing.'
               : null);
     }
-    if (!ranTests) {
+    if (!mode.integrationOnly && !ranUnitTests) {
+      printError('No unit tests ran. Plugins are required to have unit tests.');
+      return _PlatformResult(RunState.failed,
+          error: 'No unit tests ran (use --exclude if this is intentional).');
+    }
+    if (!ranAnyTests) {
       return _PlatformResult(RunState.skipped);
     }
     return _PlatformResult(RunState.succeeded);

script/tool/test/native_test_command_test.dart

@@ -430,7 +430,8 @@ void main() {
           ],
         );
 
-        await runCapturingPrint(runner, <String>['native-test', '--android']);
+        await runCapturingPrint(
+            runner, <String>['native-test', '--android', '--no-unit']);
 
         final Directory androidFolder =
             plugin.childDirectory('example').childDirectory('android');
@@ -467,7 +468,8 @@ void main() {
           ],
         );
 
-        await runCapturingPrint(runner, <String>['native-test', '--android']);
+        await runCapturingPrint(
+            runner, <String>['native-test', '--android', '--no-unit']);
 
         // Nothing should run since those files are all
         // integration_test-specific.
@@ -641,7 +643,11 @@ void main() {
         );
 
         final List<String> output = await runCapturingPrint(
-            runner, <String>['native-test', '--android']);
+            runner, <String>['native-test', '--android'],
+            errorHandler: (Error e) {
+          // Having no unit tests is fatal, but that's not the point of this
+          // test so just ignore the failure.
+        });
 
         expect(
             output,
@@ -654,7 +660,7 @@ void main() {
             ]));
       });
 
-      test('fails when a test fails', () async {
+      test('fails when a unit test fails', () async {
         final Directory pluginDir = createFakePlugin(
           'plugin',
           packagesDir,
@@ -695,6 +701,84 @@ void main() {
         );
       });
 
+      test('fails when an integration test fails', () async {
+        final Directory pluginDir = createFakePlugin(
+          'plugin',
+          packagesDir,
+          platformSupport: <String, PlatformDetails>{
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.inline)
+          },
+          extraFiles: <String>[
+            'example/android/gradlew',
+            'example/android/app/src/test/example_test.java',
+            'example/android/app/src/androidTest/IntegrationTest.java',
+          ],
+        );
+
+        final String gradlewPath = pluginDir
+            .childDirectory('example')
+            .childDirectory('android')
+            .childFile('gradlew')
+            .path;
+        processRunner.mockProcessesForExecutable[gradlewPath] = <io.Process>[
+          MockProcess(), // unit passes
+          MockProcess(exitCode: 1), // integration fails
+        ];
+
+        Error? commandError;
+        final List<String> output = await runCapturingPrint(
+            runner, <String>['native-test', '--android'],
+            errorHandler: (Error e) {
+          commandError = e;
+        });
+
+        expect(commandError, isA<ToolExit>());
+
+        expect(
+          output,
+          containsAllInOrder(<Matcher>[
+            contains('plugin/example integration tests failed.'),
+            contains('The following packages had errors:'),
+            contains('plugin')
+          ]),
+        );
+      });
+
+      test('fails if there are no unit tests', () async {
+        createFakePlugin(
+          'plugin',
+          packagesDir,
+          platformSupport: <String, PlatformDetails>{
+            kPlatformAndroid: const PlatformDetails(PlatformSupport.inline)
+          },
+          extraFiles: <String>[
+            'example/android/gradlew',
+            'example/android/app/src/androidTest/IntegrationTest.java',
+          ],
+        );
+
+        Error? commandError;
+        final List<String> output = await runCapturingPrint(
+            runner, <String>['native-test', '--android'],
+            errorHandler: (Error e) {
+          commandError = e;
+        });
+
+        expect(commandError, isA<ToolExit>());
+
+        expect(
+          output,
+          containsAllInOrder(<Matcher>[
+            contains('No Android unit tests found for plugin/example'),
+            contains(
+                'No unit tests ran. Plugins are required to have unit tests.'),
+            contains('The following packages had errors:'),
+            contains('plugin:\n'
+                '    No unit tests ran (use --exclude if this is intentional).')
+          ]),
+        );
+      });
+
       test('skips if Android is not supported', () async {
         createFakePlugin(
           'plugin',
@@ -713,7 +797,7 @@ void main() {
         );
       });
 
-      test('skips when running no tests', () async {
+      test('skips when running no tests in integration-only mode', () async {
         createFakePlugin(
           'plugin',
           packagesDir,
@@ -723,12 +807,11 @@ void main() {
         );
 
         final List<String> output = await runCapturingPrint(
-            runner, <String>['native-test', '--android']);
+            runner, <String>['native-test', '--android', '--no-unit']);
 
         expect(
           output,
           containsAllInOrder(<Matcher>[
-            contains('No Android unit tests found for plugin/example'),
             contains('No Android integration tests found for plugin/example'),
             contains('SKIPPING: No tests found.'),
           ]),