[shared_preferences_foundation] Migrate XCTest to Swift Testing #10766

jmagman · 2026-01-10T05:57:10Z

Use parameterized tests instead of testing in a for loop. I had to make the tests serializable because this shared preferences API is very un-threadsafe, and running them in parallel has many test failures where values are stomping on each other.

macOS tests

``` ◇ Test run started. ↳ Testing Library Version: 102 (arm64e-apple-macos13.0) ◇ Suite RunnerTests started. ◇ Test setAndGet(prefix:) started. ◇ Passing 1 argument prefix → "aPrefix" to setAndGet(prefix:) ◇ Passing 1 argument prefix → "" to setAndGet(prefix:) ✔ Test setAndGet(prefix:) passed after 0.001 seconds. ◇ Test getWithAllowList(prefix:) started. ◇ Passing 1 argument prefix → "aPrefix" to getWithAllowList(prefix:) ◇ Passing 1 argument prefix → "" to getWithAllowList(prefix:) ✔ Test getWithAllowList(prefix:) passed after 0.001 seconds. ◇ Test remove(prefix:) started. ◇ Passing 1 argument prefix → "aPrefix" to remove(prefix:) ◇ Passing 1 argument prefix → "" to remove(prefix:) ✔ Test remove(prefix:) passed after 0.030 seconds. ◇ Test clearWithNoAllowlist(prefix:) started. ◇ Passing 1 argument prefix → "aPrefix" to clearWithNoAllowlist(prefix:) ◇ Passing 1 argument prefix → "" to clearWithNoAllowlist(prefix:) ✔ Test clearWithNoAllowlist(prefix:) passed after 0.002 seconds. ◇ Test clearWithAllowlist(prefix:) started. ◇ Passing 1 argument prefix → "aPrefix" to clearWithAllowlist(prefix:) ◇ Passing 1 argument prefix → "" to clearWithAllowlist(prefix:) ✔ Test clearWithAllowlist(prefix:) passed after 0.001 seconds. ◇ Test asyncSetAndGet() started. ✔ Test asyncSetAndGet() passed after 0.001 seconds. ◇ Test asyncGetAll() started. ✔ Test asyncGetAll() passed after 0.001 seconds. ◇ Test asyncGetAllWithAndWithoutSuiteName() started. ✔ Test asyncGetAllWithAndWithoutSuiteName() passed after 0.001 seconds. ◇ Test asyncGetAllWithAllowList() started. ✔ Test asyncGetAllWithAllowList() passed after 0.001 seconds. ◇ Test asyncRemove() started. ✔ Test asyncRemove() passed after 0.001 seconds. ◇ Test asyncClearWithNoAllowlist() started. ✔ Test asyncClearWithNoAllowlist() passed after 0.001 seconds. ◇ Test asyncClearWithAllowlist() started. ✔ Test asyncClearWithAllowlist() passed after 0.001 seconds. ✔ Suite RunnerTests passed after 0.044 seconds. ✔ Test run with 12 tests passed after 0.044 seconds. ``` https://ci.chromium.org/ui/p/flutter/builders/try/Mac_arm64%20macos_platform_tests%20master%20-%20packages/26300/overview

iOS tests

``` Testing started Test suite 'RunnerTests' started on 'Clone 1 of Flutter-iPhone - Runner (85304)' Test case 'RunnerTests/setAndGet(prefix:)' passed on 'Clone 1 of Flutter-iPhone - Runner (85304)' (0.003 seconds) Test case 'RunnerTests/setAndGet(prefix:)' passed on 'Clone 1 of Flutter-iPhone - Runner (85304)' (0.002 seconds) Test case 'RunnerTests/getWithAllowList(prefix:)' passed on 'Clone 1 of Flutter-iPhone - Runner (85304)' (0.000 seconds) Test case 'RunnerTests/getWithAllowList(prefix:)' passed on 'Clone 1 of Flutter-iPhone - Runner (85304)' (0.000 seconds) Test case 'RunnerTests/remove(prefix:)' passed on 'Clone 1 of Flutter-iPhone - Runner (85304)' (0.001 seconds) Test case 'RunnerTests/remove(prefix:)' passed on 'Clone 1 of Flutter-iPhone - Runner (85304)' (0.001 seconds) Test case 'RunnerTests/clearWithNoAllowlist(prefix:)' passed on 'Clone 1 of Flutter-iPhone - Runner (85304)' (0.003 seconds) Test case 'RunnerTests/clearWithNoAllowlist(prefix:)' passed on 'Clone 1 of Flutter-iPhone - Runner (85304)' (0.013 seconds) Test case 'RunnerTests/clearWithAllowlist(prefix:)' passed on 'Clone 1 of Flutter-iPhone - Runner (85304)' (0.000 seconds) Test case 'RunnerTests/clearWithAllowlist(prefix:)' passed on 'Clone 1 of Flutter-iPhone - Runner (85304)' (0.000 seconds) Test case 'RunnerTests/asyncSetAndGet()' passed on 'Clone 1 of Flutter-iPhone - Runner (85304)' (0.001 seconds) Test case 'RunnerTests/asyncGetAll()' passed on 'Clone 1 of Flutter-iPhone - Runner (85304)' (0.000 seconds) Test case 'RunnerTests/asyncGetAllWithAndWithoutSuiteName()' passed on 'Clone 1 of Flutter-iPhone - Runner (85304)' (0.002 seconds) Test case 'RunnerTests/asyncGetAllWithAllowList()' passed on 'Clone 1 of Flutter-iPhone - Runner (85304)' (0.019 seconds) Test case 'RunnerTests/asyncRemove()' passed on 'Clone 1 of Flutter-iPhone - Runner (85304)' (0.001 seconds) Test case 'RunnerTests/asyncClearWithNoAllowlist()' passed on 'Clone 1 of Flutter-iPhone - Runner (85304)' (0.005 seconds) Test case 'RunnerTests/asyncClearWithAllowlist()' passed on 'Clone 1 of Flutter-iPhone - Runner (85304)' (0.002 seconds) Successfully ran iOS xctest for packages/shared_preferences/shared_preferences_foundation/example ``` https://logs.chromium.org/logs/flutter/buildbucket/cr-buildbucket/8693085104608886001/+/u/Run_package_tests/native_test/stdout

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Code Review

This pull request successfully migrates the tests for shared_preferences_foundation from XCTest to the modern Swift Testing framework. The changes are well-executed, utilizing parameterized tests to reduce boilerplate and improving test robustness by avoiding force unwraps. The decision to serialize tests is a good catch for the non-thread-safe API. I have one minor suggestion to improve consistency.

packages/shared_preferences/shared_preferences_foundation/darwin/Tests/RunnerTests.swift

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

jmagman · 2026-01-10T06:15:12Z

packages/shared_preferences/shared_preferences_foundation/example/ios/RunnerTests/.gitkeep

Xcode is expecting this directory:

macOS gets away with it because there's a (probably unnecessary) Info.plist in the equivalent directory:
https://github.com/flutter/packages/tree/fb3e9081ca58b1cb3e54b8bd471c57116a72585e/packages/shared_preferences/shared_preferences_foundation/example/macos/RunnerTests

jmagman · 2026-01-10T06:20:53Z

packages/shared_preferences/shared_preferences_foundation/darwin/Tests/RunnerTests.swift

 #endif

-class RunnerTests: XCTestCase {
+@Suite(.serialized)


Lots of test failures when these tests run in parallel. For example, there's no locking in the update methods like:

packages/packages/shared_preferences/shared_preferences_foundation/darwin/shared_preferences_foundation/Sources/shared_preferences_foundation/SharedPreferencesPlugin.swift

Lines 133 to 144 in fb3e908

func clear(allowList: [String]?, options: SharedPreferencesPigeonOptions) throws {

let defaults = try SharedPreferencesPlugin.getUserDefaults(options: options)

if let allowList = allowList {

for (key) in allowList {

defaults.removeObject(forKey: key)

}

} else {

for key in defaults.dictionaryRepresentation().keys {

defaults.removeObject(forKey: key)

}

}

}

Should probably be migrated to actor?

Surprisingly I don't see any open issues that look related.

Should probably be migrated to actor?

We now have toooo many options!

Actor

GCD

the new Synchronization framework introduced last year

Locks (os_unfair_lock is likely the most performant)

Worth adding a TODO to remove .serialized?

hellohuanlin · 2026-01-12T19:31:05Z

packages/shared_preferences/shared_preferences_foundation/darwin/Tests/RunnerTests.swift

 #endif

-class RunnerTests: XCTestCase {
+@Suite(.serialized)


Should probably be migrated to actor?

We now have toooo many options!

Actor

GCD

the new Synchronization framework introduced last year

Locks (os_unfair_lock is likely the most performant)

hellohuanlin · 2026-01-12T19:35:51Z

packages/shared_preferences/shared_preferences_foundation/darwin/Tests/RunnerTests.swift

 #endif

-class RunnerTests: XCTestCase {
+@Suite(.serialized)


Worth adding a TODO to remove .serialized?

[shared_preferences_foundation] Migrate XCTest to Swift Testing

5d99704

jmagman self-assigned this Jan 10, 2026

github-actions bot added platform-ios platform-macos p: shared_preferences labels Jan 10, 2026

gemini-code-assist bot reviewed Jan 10, 2026

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jmagman mentioned this pull request Jan 10, 2026

Migrate iOS plugin tests from XCTest to Swift Testing flutter/flutter#180787

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Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

jmagman commented Jan 10, 2026

View reviewed changes

format

c570175

jmagman marked this pull request as ready for review January 10, 2026 06:56

jmagman requested a review from tarrinneal as a code owner January 10, 2026 06:56

jmagman requested a review from hellohuanlin January 10, 2026 06:56

hellohuanlin approved these changes Jan 12, 2026

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[shared_preferences_foundation] Migrate XCTest to Swift Testing #10766

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	func clear(allowList: [String]?, options: SharedPreferencesPigeonOptions) throws {
	let defaults = try SharedPreferencesPlugin.getUserDefaults(options: options)
	if let allowList = allowList {
	for (key) in allowList {
	defaults.removeObject(forKey: key)
	}
	} else {
	for key in defaults.dictionaryRepresentation().keys {
	defaults.removeObject(forKey: key)
	}
	}
	}

[shared_preferences_foundation] Migrate XCTest to Swift Testing #10766

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