[ErrorProne] Fix BadInstanceof and enable check

[stankiewicz]

This PR removes the BadInstanceof ErrorProne check from the disabledChecks list in src/main/groovy/org/apache/beam/gradle/BeamModulePlugin.groovy to enforce it globally.
Additionally, it resolves all existing BadInstanceof warnings across the project. Most of these violations consisted of checking if an object was an instance of its own declared type or a supertype (which is always true unless the object is null). To resolve these, the redundant instanceof checks have been replaced with appropriate null checks (!= null or == null).

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[gemini-code-assist]

Summary of Changes

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This pull request significantly enhances code quality by enforcing a previously disabled ErrorProne check, BadInstanceof, throughout the codebase. The primary impact is the removal of unnecessary type checks that were effectively checking for nullability, leading to cleaner and more robust code by explicitly handling null conditions where appropriate.

Highlights

• ErrorProne Check Enabled: The BadInstanceof ErrorProne check has been removed from the disabled checks list in BeamModulePlugin.groovy, enabling it globally across the project.
• Code Quality Improvement: All existing BadInstanceof warnings have been resolved by replacing redundant instanceof checks (which were always true for non-null objects) with explicit null checks (!= null or == null).

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Changelog

• buildSrc/src/main/groovy/org/apache/beam/gradle/BeamModulePlugin.groovy
  • Removed 'BadInstanceof' from the list of disabled ErrorProne checks.
• runners/flink/2.0/src/test/java/org/apache/beam/runners/flink/translation/functions/ImpulseSourceFunctionTest.java
  • Replaced instanceof WindowedValue with a null check o != null in the matches method.
• runners/flink/src/main/java/org/apache/beam/runners/flink/FlinkStreamingTranslationContext.java
  • Updated output coders stream filter from instanceof PCollection to e.getValue() != null.
• runners/flink/src/main/java/org/apache/beam/runners/flink/PipelineTranslationModeOptimizer.java
  • Changed hasUnboundedOutput filter from instanceof PCollection to value != null.
• runners/flink/src/main/java/org/apache/beam/runners/flink/translation/utils/LookupPipelineVisitor.java
  • Replaced instanceof PCollection with e.getValue() != null in getOutputCoders.
• runners/flink/src/test/java/org/apache/beam/runners/flink/translation/functions/ImpulseSourceFunctionTest.java
  • Replaced instanceof WindowedValue with a null check o != null in the matches method.
• runners/jet/src/main/java/org/apache/beam/runners/jet/Utils.java
  • Changed getOutputValueCoders filter from instanceof PCollection to e.getValue() != null.
• runners/samza/src/main/java/org/apache/beam/runners/samza/translation/ParDoBoundMultiTranslator.java
  • Updated doTranslate output coders filter to e.getValue() != null.
  • Changed if (!(taggedOutput.getValue() instanceof PCollection)) to if (!(taggedOutput.getValue() != null)).
• runners/samza/src/main/java/org/apache/beam/runners/samza/translation/SplittableParDoTranslators.java
  • Changed conditional check from instanceof PCollection to taggedOutput.getValue() != null.
• runners/spark/src/main/java/org/apache/beam/runners/spark/translation/EvaluationContext.java
  • Updated getOutputCoders filter from instanceof PCollection to e.getValue() != null.
• runners/twister2/src/main/java/org/apache/beam/runners/twister2/Twister2TranslationContext.java
  • Changed getOutputCoders filter from instanceof PCollection to e.getValue() != null.
• sdks/java/core/src/main/java/org/apache/beam/sdk/util/construction/PTransformReplacements.java
  • Replaced input.getValue() instanceof PCollection with input.getValue() != null in getSingletonMainInput.
  • Updated error message to handle null input.getValue().
• sdks/java/core/src/main/java/org/apache/beam/sdk/util/construction/ParDoTranslation.java
  • Updated getOutputCoders filter from instanceof PCollection to e.getValue() != null.
• sdks/java/expansion-service/src/main/java/org/apache/beam/sdk/expansion/service/TransformProvider.java
  • Changed else if (output instanceof POutput) to else if (output != null) in extractOutputs.
• sdks/java/io/google-cloud-platform/src/test/java/org/apache/beam/sdk/io/gcp/spanner/ReadSpannerSchemaTest.java
  • Replaced !(argument instanceof Statement) with argument == null in prepareColumnMetadata.
  • Replaced !(argument instanceof Statement) with argument == null in preparePkMetadata.
• sdks/java/io/google-cloud-platform/src/test/java/org/apache/beam/sdk/io/gcp/spanner/SpannerIOWriteTest.java
  • Replaced !(argument instanceof Statement) with argument == null in prepareColumnMetadata.
  • Replaced !(argument instanceof Statement) with argument == null in preparePgColumnMetadata.
  • Replaced !(argument instanceof Statement) with argument == null in preparePkMetadata.
  • Replaced !(argument instanceof Iterable) with argument == null in mutationsInNoOrder.
• sdks/java/testing/nexmark/src/main/java/org/apache/beam/sdk/nexmark/queries/Query4Model.java
  • Changed Assert.assertTrue condition from obj.getValue() instanceof CategoryPrice to obj.getValue() != null.
• sdks/java/testing/nexmark/src/main/java/org/apache/beam/sdk/nexmark/queries/Query6Model.java
  • Changed Assert.assertTrue condition from obj.getValue() instanceof SellerPrice to obj.getValue() != null.

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[stankiewicz]

/gemini review

[gemini-code-assist]

Code Review

This pull request enables the BadInstanceof ErrorProne check globally and fixes the existing violations. The changes correctly replace redundant instanceof checks with null checks. The approach is sound and the modifications across the various files are consistent with the goal. I've added a couple of suggestions to improve readability by simplifying a boolean expression, consistent with changes made in other parts of this PR.

[github-actions]

Checks are failing. Will not request review until checks are succeeding. If you'd like to override that behavior, comment assign set of reviewers

[stankiewicz]

Run Java_Amazon-Web-Services2_IO_Direct PreCommit