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Merged
merged 2 commits into from
Oct 17, 2025
Merged

Remove backup expectations #2209

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50dd650
Remove backup test assertions.
davidmorgan Oct 14, 2025
166c386
Add a way to run tests many times in parallel.
davidmorgan Oct 16, 2025
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44 changes: 8 additions & 36 deletions pkgs/watcher/test/directory_watcher/file_tests.dart
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Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,12 @@ import 'package:watcher/src/utils.dart';
import '../utils.dart';

void fileTests() {
for (var i = 0; i != runsPerTest; ++i) {
_fileTests();
}
}

void _fileTests() {
test('does not notify for files that already exist when started', () async {
// Make some pre-existing files.
writeFile('a.txt');
Expand Down Expand Up @@ -141,27 +147,13 @@ void fileTests() {
});
});

// Most of the time, when multiple filesystem actions happen in sequence,
// they'll be batched together and the watcher will see them all at once.
// These tests verify that the watcher normalizes and combine these events
// properly. However, very occasionally the events will be reported in
// separate batches, and the watcher will report them as though they occurred
// far apart in time, so each of these tests has a "backup case" to allow for
// that as well.
group('clustered changes', () {
test("doesn't notify when a file is created and then immediately removed",
() async {
writeFile('test.txt');
await startWatcher();
writeFile('file.txt');
deleteFile('file.txt');

// Backup case.
startClosingEventStream();
await allowEvents(() {
expectAddEvent('file.txt');
expectRemoveEvent('file.txt');
});
});

test(
Expand All @@ -173,13 +165,7 @@ void fileTests() {
deleteFile('file.txt');
writeFile('file.txt', contents: 're-created');

await allowEither(() {
expectModifyEvent('file.txt');
}, () {
// Backup case.
expectRemoveEvent('file.txt');
expectAddEvent('file.txt');
});
await expectModifyEvent('file.txt');
});

test(
Expand All @@ -191,14 +177,7 @@ void fileTests() {
renameFile('old.txt', 'new.txt');
writeFile('old.txt', contents: 're-created');

await allowEither(() {
inAnyOrder([isModifyEvent('old.txt'), isAddEvent('new.txt')]);
}, () {
// Backup case.
expectRemoveEvent('old.txt');
expectAddEvent('new.txt');
expectAddEvent('old.txt');
});
await inAnyOrder([isModifyEvent('old.txt'), isAddEvent('new.txt')]);
});

test(
Expand All @@ -210,9 +189,6 @@ void fileTests() {
writeFile('file.txt', contents: 'modified');
deleteFile('file.txt');

// Backup case.
await allowModifyEvent('file.txt');

await expectRemoveEvent('file.txt');
});

Expand All @@ -224,10 +200,6 @@ void fileTests() {
writeFile('file.txt', contents: 'modified');

await expectAddEvent('file.txt');

// Backup case.
startClosingEventStream();
await allowModifyEvent('file.txt');
});
});

Expand Down
6 changes: 6 additions & 0 deletions pkgs/watcher/test/directory_watcher/link_tests.dart
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Expand Up @@ -9,6 +9,12 @@ import 'package:test/test.dart';
import '../utils.dart';

void linkTests({required bool isNative}) {
for (var i = 0; i != runsPerTest; ++i) {
_linkTests(isNative: isNative);
}
}

void _linkTests({required bool isNative}) {
test('notifies when a link is added', () async {
createDir('targets');
createDir('links');
Expand Down
14 changes: 4 additions & 10 deletions pkgs/watcher/test/directory_watcher/linux_test.dart
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Original file line number Diff line number Diff line change
Expand Up @@ -32,15 +32,9 @@ void main() {
renameDir('dir/sub', 'sub');
renameDir('sub', 'dir/sub');

await allowEither(() {
inAnyOrder(withPermutations(
(i, j, k) => isRemoveEvent('dir/sub/sub-$i/sub-$j/file-$k.txt')));

inAnyOrder(withPermutations(
(i, j, k) => isAddEvent('dir/sub/sub-$i/sub-$j/file-$k.txt')));
}, () {
inAnyOrder(withPermutations(
(i, j, k) => isModifyEvent('dir/sub/sub-$i/sub-$j/file-$k.txt')));
});
await inAnyOrder(withPermutations(
(i, j, k) => isRemoveEvent('dir/sub/sub-$i/sub-$j/file-$k.txt')));
await inAnyOrder(withPermutations(
(i, j, k) => isAddEvent('dir/sub/sub-$i/sub-$j/file-$k.txt')));
});
}
14 changes: 4 additions & 10 deletions pkgs/watcher/test/directory_watcher/mac_os_test.dart
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Original file line number Diff line number Diff line change
Expand Up @@ -46,16 +46,10 @@ void main() {
renameDir('dir/sub', 'sub');
renameDir('sub', 'dir/sub');

await allowEither(() {
inAnyOrder(withPermutations(
(i, j, k) => isRemoveEvent('dir/sub/sub-$i/sub-$j/file-$k.txt')));

inAnyOrder(withPermutations(
(i, j, k) => isAddEvent('dir/sub/sub-$i/sub-$j/file-$k.txt')));
}, () {
inAnyOrder(withPermutations(
(i, j, k) => isModifyEvent('dir/sub/sub-$i/sub-$j/file-$k.txt')));
});
await inAnyOrder(withPermutations(
(i, j, k) => isRemoveEvent('dir/sub/sub-$i/sub-$j/file-$k.txt')));
await inAnyOrder(withPermutations(
(i, j, k) => isAddEvent('dir/sub/sub-$i/sub-$j/file-$k.txt')));
});
test('does not suppress files with the same prefix as a directory', () async {
// Regression test for https://github.com/dart-lang/watcher/issues/83
Expand Down
10 changes: 6 additions & 4 deletions pkgs/watcher/test/file_watcher/file_tests.dart
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Original file line number Diff line number Diff line change
Expand Up @@ -13,11 +13,13 @@ void fileTests({required bool isNative}) {
writeFile('file.txt');
});

for (var i = 0; i != runsPerTest; ++i) {
_fileTests(isNative: isNative);
}
}

void _fileTests({required bool isNative}) {
test("doesn't notify if the file isn't modified", () async {
// TODO(davidmorgan): fix startup race on MacOS.
if (isNative && Platform.isMacOS) {
await Future<void>.delayed(const Duration(milliseconds: 100));
}
await startWatcher(path: 'file.txt');
await expectNoEvents();
});
Expand Down
6 changes: 6 additions & 0 deletions pkgs/watcher/test/file_watcher/link_tests.dart
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Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,12 @@ void linkTests({required bool isNative}) {
writeLink(link: 'link.txt', target: 'target.txt');
});

for (var i = 0; i != runsPerTest; ++i) {
_linkTests(isNative: isNative);
}
}

void _linkTests({required bool isNative}) {
test("doesn't notify if nothing is modified", () async {
await startWatcher(path: 'link.txt');
await expectNoEvents();
Expand Down
71 changes: 11 additions & 60 deletions pkgs/watcher/test/utils.dart
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Expand Up @@ -12,6 +12,9 @@ import 'package:test_descriptor/test_descriptor.dart' as d;
import 'package:watcher/src/stat.dart';
import 'package:watcher/watcher.dart';

/// Edit this to run fast-running tests many times.
int runsPerTest = 1;

typedef WatcherFactory = Watcher Function(String directory);

/// Sets the function used to create the watcher.
Expand Down Expand Up @@ -164,62 +167,18 @@ void startClosingEventStream() async {
await _watcherEvents.cancel(immediate: true);
}

/// A list of [StreamMatcher]s that have been collected using
/// [_collectStreamMatcher].
List<StreamMatcher>? _collectedStreamMatchers;

/// Collects all stream matchers that are registered within [block] into a
/// single stream matcher.
///
/// The returned matcher will match each of the collected matchers in order.
StreamMatcher _collectStreamMatcher(void Function() block) {
var oldStreamMatchers = _collectedStreamMatchers;
var collectedStreamMatchers = _collectedStreamMatchers = <StreamMatcher>[];
try {
block();
return emitsInOrder(collectedStreamMatchers);
} finally {
_collectedStreamMatchers = oldStreamMatchers;
}
}

/// Either add [streamMatcher] as an expectation to [_watcherEvents], or collect
/// it with [_collectStreamMatcher].
/// Add [streamMatcher] as an expectation to [_watcherEvents].
///
/// [streamMatcher] can be a [StreamMatcher], a [Matcher], or a value.
Future _expectOrCollect(Matcher streamMatcher) {
var collectedStreamMatchers = _collectedStreamMatchers;
if (collectedStreamMatchers != null) {
collectedStreamMatchers.add(emits(streamMatcher));
return Future.sync(() {});
} else {
return expectLater(_watcherEvents, emits(streamMatcher));
}
Future _expect(Matcher streamMatcher) {
return expectLater(_watcherEvents, emits(streamMatcher));
}

/// Expects that [matchers] will match emitted events in any order.
///
/// [matchers] may be [Matcher]s or values, but not [StreamMatcher]s.
Future inAnyOrder(Iterable matchers) {
matchers = matchers.toSet();
return _expectOrCollect(emitsInAnyOrder(matchers));
}

/// Expects that the expectations established in either [block1] or [block2]
/// will match the emitted events.
///
/// If both blocks match, the one that consumed more events will be used.
Future allowEither(void Function() block1, void Function() block2) =>
_expectOrCollect(emitsAnyOf(
[_collectStreamMatcher(block1), _collectStreamMatcher(block2)]));

/// Allows the expectations established in [block] to match the emitted events.
///
/// If the expectations in [block] don't match, no error will be raised and no
/// events will be consumed. If this is used at the end of a test,
/// [startClosingEventStream] should be called before it.
Future allowEvents(void Function() block) =>
_expectOrCollect(mayEmit(_collectStreamMatcher(block)));
Future inAnyOrder(Iterable matchers) =>
_expect(emitsInAnyOrder(matchers.toSet()));

/// Returns a StreamMatcher that matches a [WatchEvent] with the given [type]
/// and [path].
Expand Down Expand Up @@ -274,24 +233,16 @@ Future<List<WatchEvent>> takeEvents({required Duration duration}) async {

/// Expects that the next event emitted will be for an add event for [path].
Future expectAddEvent(String path) =>
_expectOrCollect(isWatchEvent(ChangeType.ADD, path));
_expect(isWatchEvent(ChangeType.ADD, path));

/// Expects that the next event emitted will be for a modification event for
/// [path].
Future expectModifyEvent(String path) =>
_expectOrCollect(isWatchEvent(ChangeType.MODIFY, path));
_expect(isWatchEvent(ChangeType.MODIFY, path));

/// Expects that the next event emitted will be for a removal event for [path].
Future expectRemoveEvent(String path) =>
_expectOrCollect(isWatchEvent(ChangeType.REMOVE, path));

/// Consumes a modification event for [path] if one is emitted at this point in
/// the schedule, but doesn't throw an error if it isn't.
///
/// If this is used at the end of a test, [startClosingEventStream] should be
/// called before it.
Future allowModifyEvent(String path) =>
_expectOrCollect(mayEmit(isWatchEvent(ChangeType.MODIFY, path)));
_expect(isWatchEvent(ChangeType.REMOVE, path));

/// Track a fake timestamp to be used when writing files. This always increases
/// so that files that are deleted and re-created do not have their timestamp
Expand Down