Enable Java lints for the plugins/packages repos

[bparrishMines]

A linter runs for the Dart code and Objective-C/Swift code in the flutter/plugins and flutter/packages repos.

This issue tracks enabling it for Java and Kotlin.

We should be able to just use the command provided by gradle:
See https://developer.android.com/studio/write/lint

gradlew lint
./gradlew lint

I would imagine we would initially need a config file to exclude plugins and fix the lint warnings incrementally.

cc @camsim99 @reidbaker @stuartmorgan FYI

[bparrishMines]

@stuartmorgan Is this something we could do before or after #113764?

[stuartmorgan-g]

I we do it before, we just need to make sure it's added in parallel to both repos so we don't re-diverge their test set.

I would imagine we would initially need a config file to exclude plugins and fix the lint warnings incrementally.

We already have lint_baseline.xml set up as part of uploading build warning output, so hopefully we could just update that.

[stuartmorgan-g]

Would this address #91868 for Android, or are lint warnings and build warnings disjoint?

[reidbaker]

I am pro making this happen.

[stuartmorgan-g]

We already have lint_baseline.xml set up as part of uploading build warning output

... which we have because I set up a command over a year ago that runs this lint command (lint-android). I forgot that's what it was doing 🤦🏻

Closing as a duplicate of #87071. I'll look into why some warnings aren't being flagged by this, like flutter/packages#3273. Maybe it's just the exclusions, and what we need is a push to remove exclusions that were set up when we turned this on?

[stuartmorgan-g]

I'll look into why some warnings aren't being flagged by this, like flutter/packages#3273. Maybe it's just the exclusions, and what we need is a push to remove exclusions that were set up when we turned this on?

It looks like having warnings output doesn't cause it to return a non-zero exit code. Re-opening while I investigate further.

[stuartmorgan-g]

Also, while not relevant to it not failing CI, it appears that running the lint command twice only outputs warnings the first time, which is definitely not a behavior we want.

[stuartmorgan-g]

It looks like having warnings output doesn't cause it to return a non-zero exit code. Re-opening while I investigate further.

Investigating further: I'm not crazy thinking I had to set up baselines to get things to pass when I first did this, I just wasn't looking at the output closely enough. The output I was seeing was:

> Task :camera_android:lintDebug
Lint found no errors or warnings

2 errors/warnings were listed in the baseline file (/Users/stuartmorgan/src/packages/packages/camera/camera_android/android/lint-baseline.xml) but not found in the project; perhaps they have been fixed?

Deprecated Gradle features were used in this build, making it incompatible with Gradle 8.0.
Use '--warning-mode all' to show the individual deprecation warnings.
See https://docs.gradle.org/7.0.2/userguide/command_line_interface.html#sec:command_line_warnings

BUILD SUCCESSFUL in 1s
52 actionable tasks: 52 executed
/Users/stuartmorgan/src/packages/packages/camera/camera_android/android/src/main/java/io/flutter/plugins/camera/features/resolution/ResolutionFeature.java:158: warning: [deprecation] get(int,int) in CamcorderProfile has been deprecated
          return CamcorderProfile.get(cameraId, CamcorderProfile.QUALITY_HIGH);
                                 ^
/Users/stuartmorgan/src/packages/packages/camera/camera_android/android/src/main/java/io/flutter/plugins/camera/features/resolution/ResolutionFeature.java:162: warning: [deprecation] get(int,int) in CamcorderProfile has been deprecated
          return CamcorderProfile.get(cameraId, CamcorderProfile.QUALITY_2160P);
                                 ^
/Users/stuartmorgan/src/packages/packages/camera/camera_android/android/src/main/java/io/flutter/plugins/camera/features/resolution/ResolutionFeature.java:166: warning: [deprecation] get(int,int) in CamcorderProfile has been deprecated
          return CamcorderProfile.get(cameraId, CamcorderProfile.QUALITY_1080P);
                                 ^
/Users/stuartmorgan/src/packages/packages/camera/camera_android/android/src/main/java/io/flutter/plugins/camera/features/resolution/ResolutionFeature.java:170: warning: [deprecation] get(int,int) in CamcorderProfile has been deprecated
          return CamcorderProfile.get(cameraId, CamcorderProfile.QUALITY_720P);
                                 ^
/Users/stuartmorgan/src/packages/packages/camera/camera_android/android/src/main/java/io/flutter/plugins/camera/features/resolution/ResolutionFeature.java:174: warning: [deprecation] get(int,int) in CamcorderProfile has been deprecated
          return CamcorderProfile.get(cameraId, CamcorderProfile.QUALITY_480P);
                                 ^
/Users/stuartmorgan/src/packages/packages/camera/camera_android/android/src/main/java/io/flutter/plugins/camera/features/resolution/ResolutionFeature.java:178: warning: [deprecation] get(int,int) in CamcorderProfile has been deprecated
          return CamcorderProfile.get(cameraId, CamcorderProfile.QUALITY_QVGA);
                                 ^
/Users/stuartmorgan/src/packages/packages/camera/camera_android/android/src/main/java/io/flutter/plugins/camera/features/resolution/ResolutionFeature.java:182: warning: [deprecation] get(int,int) in CamcorderProfile has been deprecated
          return CamcorderProfile.get(cameraId, CamcorderProfile.QUALITY_LOW);
                                 ^
7 warnings

I missed the Lint found no errors or warnings bit. So those warnings are being dumped to the console when I run lint as part of the overall gradle run, but aren't part of the lint step itself. That may also explain why it doesn't output anything when run a second time; it's not the step actually being targetted.

[stuartmorgan-g]

Okay, it looks like what's happening here is that the Gradle lint is different from javac lints, and the deprecation warnings are coming from the latter. So this is a duplicate, and the above would be #91868

[github-actions]

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