fix: 🐛 Add equality and hashCode implementations to ScrollAwareImageProvider

[Yash-Dhrangdhariya]

Description

This PR adds == and hashCode implementations to ScrollAwareImageProvider.

According to the ImageProvider documentation:

It should be immutable and implement the == operator and the hashCode getter.

ScrollAwareImageProvider did not previously override these, which could result in instances with identical configuration being treated as unequal. This behavior can negatively impact image caching and equality checks.

With this change, ScrollAwareImageProvider now conforms to the ImageProvider contract.

Pre-launch Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I read the Tree Hygiene wiki page, which explains my responsibilities.
• I read and followed the Flutter Style Guide, including Features we expect every widget to implement.
• I signed the CLA.
• I listed at least one issue that this PR fixes in the description above.
• I updated/added relevant documentation (doc comments with ///).
• I added new tests to check the change I am making, or this PR is test-exempt.
• I followed the breaking change policy and added Data Driven Fixes where supported.
• All existing and new tests are passing.

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[gemini-code-assist]

Code Review

This pull request correctly implements operator== and hashCode for ScrollAwareImageProvider, aligning it with the ImageProvider contract. This is an important fix that will improve image caching and equality checks. The added @immutable annotation is also appropriate. The new tests effectively validate the changes. I have one minor suggestion to further improve test coverage.

[gemini-code-assist]

The test coverage for equality is good. To make it more comprehensive, you could add a test case to verify that two ScrollAwareImageProvider instances are not equal if their context is different, while their imageProvider is the same. This would ensure all properties contributing to equality are also tested for inequality.

For example:

testWidgets('Instances with different contexts should not be equal', (WidgetTester tester) async {
  final DisposableBuildContext context1 = await createContext(tester);
  final DisposableBuildContext context2 = await createContext(tester);

  final TestImageProvider testImageProvider = TestImageProvider(testImage.clone());

  final ScrollAwareImageProvider<TestImageProvider> image1 =
      ScrollAwareImageProvider<TestImageProvider>(
        context: context1,
        imageProvider: testImageProvider,
      );

  final ScrollAwareImageProvider<TestImageProvider> image2 =
      ScrollAwareImageProvider<TestImageProvider>(
        context: context2,
        imageProvider: testImageProvider,
      );

  expect(image1 == image2, isFalse);
});

[justinmc]

Not a big deal but I guess I agree with Gemini here.

[justinmc]

Thanks for the PR!

[justinmc]

Move this to immediately after testImage2 is created. That way, if there is an error before this line, it will still get disposed.

[justinmc]

Can you add an expect for the hashCode too? Might as well.

[justinmc]

Not a big deal but I guess I agree with Gemini here.

[justinmc]

@Yash-Dhrangdhariya Thanks for the quick response! I'll re-review in a bit, but FYI check out the failures here now.

[Yash-Dhrangdhariya]

@justinmc Thanks for the heads-up! I’ve updated the PR— all test cases are passing.

[justinmc]

LGTM 👍

[ksokolovskyi]

LGTM, thanks a lot for your contribution!