Give `_runFlutterTest` the ability to validate command output
In another change (#37646), I want to test that a test fails and
prints expected output. I didn't see an existing way to do that, so
I modified `_runFlutterTest` and `runCommand` to allow capturing the
output. Currently capturing and printing output are mutually
exclusive since we don't need both.
Some awkward bits:
* There already exists a `runAndGetStdout` function that is very
similar to `runCommand`, and this change makes the conceptual
distinction more confusing.
* `runFlutterTest` has multiple code paths for different
configurations. I don't understand what the different paths are
for, and I added output checking only along one of them.
diff --git a/dev/bots/test.dart b/dev/bots/test.dart
index c5234e1..6a49654 100644
--- a/dev/bots/test.dart
+++ b/dev/bots/test.dart
@@ -15,6 +15,14 @@
typedef ShardRunner = Future<void> Function();
+/// A function used to validate the output of a test.
+///
+/// If the output matches expectations, the function shall return null.
+///
+/// If the output does not match expectations, the function shall return an
+/// appropriate error message.
+typedef OutputChecker = String Function(CapturedOutput);
+
final String flutterRoot = path.dirname(path.dirname(path.dirname(path.fromUri(Platform.script))));
final String flutter = path.join(flutterRoot, 'bin', Platform.isWindows ? 'flutter.bat' : 'flutter');
final String dart = path.join(flutterRoot, 'bin', 'cache', 'dart-sdk', 'bin', Platform.isWindows ? 'dart.exe' : 'dart');
@@ -142,7 +150,7 @@
<String>['drive', '--use-existing-app', '-t', path.join('test_driver', 'failure.dart')],
workingDirectory: path.join(flutterRoot, 'packages', 'flutter_driver'),
expectNonZeroExit: true,
- printOutput: false,
+ outputMode: OutputMode.discard,
timeout: _kShortTimeout,
),
],
@@ -765,8 +773,6 @@
}
Future<void> _runFlutterWebTest(String workingDirectory, {
- bool printOutput = true,
- bool skip = false,
Duration timeout = _kLongTimeout,
List<String> tests,
}) async {
@@ -802,6 +808,7 @@
String script,
bool expectFailure = false,
bool printOutput = true,
+ OutputChecker outputChecker,
List<String> options = const <String>[],
bool skip = false,
Duration timeout = _kLongTimeout,
@@ -809,6 +816,9 @@
Map<String, String> environment,
List<String> tests = const <String>[],
}) async {
+ // Support printing output or capturing it for matching, but not both.
+ assert(_implies(printOutput, outputChecker == null));
+
final List<String> args = <String>[
'test',
...options,
@@ -838,14 +848,38 @@
args.addAll(tests);
if (!shouldProcessOutput) {
- return runCommand(flutter, args,
+ OutputMode outputMode = OutputMode.discard;
+ CapturedOutput output;
+
+ if (outputChecker != null) {
+ outputMode = OutputMode.capture;
+ output = CapturedOutput();
+ } else if (printOutput) {
+ outputMode = OutputMode.print;
+ }
+
+ await runCommand(
+ flutter,
+ args,
workingDirectory: workingDirectory,
expectNonZeroExit: expectFailure,
- printOutput: printOutput,
+ outputMode: outputMode,
+ output: output,
skip: skip,
timeout: timeout,
environment: environment,
);
+
+ if (outputChecker != null) {
+ final String message = outputChecker(output);
+ if (message != null) {
+ print('$redLine');
+ print(message);
+ print('$redLine');
+ exit(1);
+ }
+ }
+ return;
}
if (useFlutterTestFormatter) {
@@ -975,3 +1009,8 @@
await _runDevicelabTest('module_host_with_custom_build_test', env: env);
}
}
+
+/// Returns true if `p` logically implies `q`, false otherwise.
+///
+/// If `p` is true, `q` must be true.
+bool _implies(bool p, bool q) => !p || q;
