review-fixes-javac-fail

name	review-fixes-javac-fail
description	Review pull requests with the `fixes-javac-fail` label in graalvm-reachability-metadata. Use when asked to review or triage a PR that fixes Java compilation failures for an existing library version update. Focus on validating the compile fix, keeping the diff scoped, and ensuring the dynamic-access coverage percentage does not drop by more than 20 percentage points between the previously tested version and the new version.
argument-hint	[pr-number-or-url]

Review fixes-javac-fail PRs

These PRs repair test sources or test dependencies after an existing library is bumped and the new version no longer compiles with the old test code. Review them more lightly than library-new-request PRs: the library already exists, so the goal is to preserve working coverage across the version update rather than prove a brand-new metadata contribution from scratch.

The PR number or URL can be passed as an optional argument (for example, 1234, https://github.com/oracle/graalvm-reachability-metadata/pull/1234). If the user says "review this PR" without an argument, infer the PR from the surrounding conversation or gh pr status; only ask the user when it cannot be inferred. Use gh pr view <pr>, gh pr diff <pr>, and gh pr checks <pr> against the resolved PR throughout the workflow below.

Review Principles

• Confirm the PR has label fixes-javac-fail.
• Expect compile-focused changes plus the normal generated support files for the newly tested version: test source updates, imports, renamed APIs, dependency adjustments, a new metadata-version directory, stats, and metadata index changes.
• Be more relaxed than library-new-request: do not reject only because a test resembles older coverage, stays in an existing package layout, or contains compatibility branches for multiple supported versions.
• Do not accept changes that remove meaningful test coverage just to make javac pass.
• Native-image execution should remain enabled by default when the repaired test reaches the native lane. Do not accept changes that skip or short-circuit native-image behavior. When a test exercises behavior that fundamentally relies on open-ended dynamic class loading that native image cannot support, such as loading classes, JARs, generated bytecode, plugin implementations, or other class definitions that are only discovered after the native executable is built, accept the NativeImageSupport.isUnsupportedFeatureError(e) catch pattern from org.graalvm.internal.tck. Reject raw native-only skips, bare catch (Error) blocks, and use of this pattern for ordinary reflection, resources, serialization, dynamic proxies, JNI, or missing reachability metadata.
• Treat dynamic-access coverage preservation as the main quality gate, compared by percentage only. Do not treat changes in absolute covered or total call counts as a drop. The new version should not report a coverage percentage more than 20 percentage points lower than the previously tested version unless the PR gives a concrete, credible reason.
• For numeric gates, compare the reported evidence as-is. Do not inspect generation filters, agent configuration, or metadata contents to second-guess why dynamic-access or metadata-count numbers are what they are.
• Compare total metadata entry counts between the previous metadata version and the new metadata version only as a severe-drop guardrail, using the counts reported in the PR description. When the PR reports both library metadata entries and test-only metadata entries, sum them for that version's total. Report metadata entry count issues only when the PR-reported new total metadata entry count has fewer than 25% as many entries as the PR-reported original count.
• A new version that reports zero dynamic-access calls (for example dynamicAccess.totalCalls == 0, or a {} reachability-metadata.json with no claimed dynamic-access behavior) does not give enough information to judge whether metadata is unnecessary or whether a metadata-entry-count drop is meaningful. Dynamic-access stats can miss metadata required through transitive dependencies. Do not report a metadata-entry-count drop, and do not flag a shallow test or a test that exercises behavior outside the library's responsibility, as a blocking issue or human-intervention for such a library. The compile fix itself must still pass and must not be made green by deleting meaningful coverage or disabling native-image behavior.
• Accept only reachability-metadata.json files as metadata files. Reject legacy native-image metadata config files such as reflect-config.json, resource-config.json, proxy-config.json, serialization-config.json, jni-config.json, or predefined-classes-config.json.
• Prefer small, targeted review comments. This label is for repair work, not a full redesign of historical tests.

Workflow

1. Inspect the PR summary.

   • Resolve the target PR from the optional argument, or infer it from context when possible.
   • Confirm the PR has label fixes-javac-fail.
   • Identify the target coordinate, the previous tested version, and the new tested version from the PR body, title, changed index.json, and changed test path.
   • Gather files, reviews, inline comments, and CI checks.

2. Validate the diff scope.

   • Expected files are usually limited to the target coordinate's generated new-version support:
     • metadata/<group>/<artifact>/<new-version>/reachability-metadata.json
     • metadata/<group>/<artifact>/index.json
     • stats/<group>/<artifact>/<new-version>/stats.json
     • tests/src/<group>/<artifact>/<new-version>/**
   • Accept compatibility edits that keep one test source working across multiple tested versions.
   • Treat a new reachability-metadata.json for the tested version as normal for this label, including {} when validation and stats are coherent.
   • Treat generated test project files such as .gitignore, build.gradle, gradle.properties, settings.gradle, and user-code-filter.json as normal when they live under the target version's test directory.
   • Be suspicious of unrelated build logic, workflows, generated sources, other libraries, or broad refactors.
   • Reject legacy native-image metadata config files. Metadata for generated support and test-only metadata must use reachability-metadata.json.
   • Reject or request changes if the PR removes tests, disables test classes, catches and ignores the failing exception, or disables native-image behavior.
   • Accept the NativeImageSupport.isUnsupportedFeatureError(e) catch pattern for tests that exercise behavior fundamentally requiring unsupported open-ended dynamic class loading. Reject bare catch (Error) blocks without the isUnsupportedFeatureError verification.

3. Review the compile fix.

   • Confirm the edit addresses the actual Java compilation failure, such as renamed classes, changed method signatures, module boundaries, annotation processors, or dependency coordinates.
   • Compatibility branches are acceptable when they keep older and newer tested versions covered by the same test.
   • Version-specific logic is acceptable when the upstream API genuinely changed, but it should be narrow and documented by the code structure or assertions.
   • Do not require the stricter library-new-request rules about scaffold-only tests or test package placement unless the PR is also adding a new library.

4. Check dynamic-access coverage across versions.

   • Compare stats/<group>/<artifact>/<old-metadata-version>/stats.json and stats/<group>/<artifact>/<new-metadata-version>/stats.json when stats files are present in the PR or available on the branch.
   • Compare dynamicAccess.coverageRatio (or the percentage reported in the PR description) for the overall report and the dynamicAccess.breakdown entries for reflection, resources, proxies, serialization, JNI, or any other present report type. Use coveredCalls and totalCalls only to compute percentages; do not compare the absolute counts between versions.
   • Do not use user-code-filter.json, agent configuration, or metadata file contents to argue that the reported dynamic-access values are not comparable. Use the stats values as reported unless the stats are missing or stale.
   • A coverage percentage drop of more than 20 percentage points for the new version is blocking unless the PR explains why the reduction is expected. Percentage drops of 20 points or less, and any reduction in absolute coveredCalls or totalCalls, are not drops and must not be reported as regressions.
   • If stats are missing or stale, ask for generateLibraryStats or the relevant CI stats job before approving.

5. Compare metadata entry counts.

   • Compare total metadata entry counts for the previous metadata version and the new metadata version from the PR description, matching summary fields such as Metadata entries, legacy Entries or Entries found, Test-only metadata entries, Metadata entries (new ...), Test-only metadata entries (new ...), Previous library version metadata entries, and Previous library version test-only metadata entries.
   • Treat each version's total as library metadata entries plus test-only metadata entries when both are reported.
   • Do not manually count entries from metadata files.
   • Do not use metadata file contents to argue that passing reported entry counts are incomplete.
   • Do not require an exact match. Differences are normal when upstream APIs move, generated metadata is cleaned up, or dynamic-access totals change.
   • Do not report metadata entry count issues unless the PR-reported new total metadata entry count is lower than 25% of the PR-reported original total metadata entry count.
   • When the new total is below 25% of the original and the tests and dynamic-access stats still claim comparable coverage, ask for restored metadata or a concrete explanation of the API/package change.
   • Skip this comparison entirely when the new version reports zero dynamic-access calls. A zero-call report gives too little information to judge metadata relevance, so a metadata-entry-count drop for it is not a reliable review signal and must not be reported or escalated.
   • If the PR description does not report usable old and new metadata entry counts, do not infer them from metadata files; ask for refreshed PR summary evidence when the comparison is needed.

6. Check CI before deciding.

   • Expected minimum: compileTestJava or equivalent changed-metadata compile checks are green for the target coordinate.
   • Prefer seeing the full target test lane green because a compile fix can still reduce runtime or native coverage.
   • If current-defaults and future-defaults lanes both run, both should pass unless the PR clearly targets only one failing lane and the other failure is unrelated infrastructure noise.
   • If CI is flaky but the diff and coverage comparison are sound, ask for a rerun instead of blocking on speculation.

Decision Rules

Approve when all of these are true:

• The PR is scoped to the target existing library and the compile failure it fixes.
• Tests still exercise the same meaningful library behavior after the compile repair.
• The dynamic-access coverage percentage does not drop by more than 20 percentage points between the previous and new tested versions, or a larger drop is convincingly explained by a changed upstream API surface.
• Total metadata entry counts are not below the 25% severe-drop threshold, or the reduction is convincingly explained by a changed upstream API surface, or the new version reports zero dynamic-access calls and the metadata-entry-count comparison is skipped.
• Required compile and metadata test checks are green.

Request changes when any of these are true:

• The fix makes compilation pass by weakening or bypassing the test instead of adapting it to the changed API while preserving meaningful coverage.
• The fix disables native-image behavior instead of using the NativeImageSupport.isUnsupportedFeatureError(e) catch pattern for unsupported open-ended dynamic class loading.
• The dynamic-access coverage percentage drops by more than 20 percentage points without a credible explanation and replacement coverage.
• Total metadata entry count drops below 25% of the original without a credible explanation for a new version that reports non-zero dynamic-access calls.
• CI failures indicate the compile problem is not actually fixed.

Ask for follow-up instead of rejecting when:

• Stats needed for the old/new version comparison are missing or stale.
• CI failed in a way that looks like infrastructure noise.
• The API change is plausible but the PR does not explain why a coverage percentage drop of more than 20 percentage points is expected.
• Total metadata entry count drops below 25% of the original for a new version that reports non-zero dynamic-access calls, but the changed upstream API surface makes the reduction plausible.

Output Style

Keep comments short and factual:

• For coverage drops: report only drops where the new version's coverage percentage is more than 20 percentage points below the previous version's; cite the old and new percentages, and ask for either restored coverage or a concrete explanation. Do not comment on changes in absolute covered or total call counts.
• For metadata entry drops: report only drops where the new version reports non-zero dynamic-access calls and the new total metadata has fewer than 25% as many entries as the previous version's total metadata; cite the old and new counts, and ask for either restored metadata or a concrete explanation of the API/runtime-surface change. Do not report a metadata entry drop, and do not flag a shallow or off-target test, when the new version reports zero dynamic-access calls, because that signal is not enough to judge metadata relevance.
• For deleted coverage: say that the PR fixes compilation by removing coverage and should instead adapt the test to the new API.
• For native skips that does not depend on the open-ended dynamic class loading: say that the PR avoids the failing native path instead of fixing it, so it does not demonstrate native-image runtime coverage.
• For unverified catch (Error): say that dynamic class loading tests should verify Native Image failures with NativeImageSupport.isUnsupportedFeatureError(e) and re-throw any other error.
• For version-pinned tests: say that tests should not reference the exact library version because the same test should support multiple library versions.
• For unrelated changes: say the PR should stay scoped to the fixes-javac-fail repair and remove unrelated files.
• For legacy metadata files: say that metadata must use reachability-metadata.json and ask for old config files such as reflect-config.json or resource-config.json to be replaced.
• For missing stats: ask for regenerated library stats or CI evidence before approval.

Examples

Use these examples as representative patterns, not exhaustive matchers.

• Bad compile repair that removes coverage:

@Test
void parsesDocument() {
    // Removed assertions because the new API no longer compiles.
}

• Bad native-image skip:

@Test
void parsesDocument() {
    assumeFalse("runtime".equals(System.getProperty("org.graalvm.nativeimage.imagecode")));

    Document document = Parser.parse("name=value");
    assertThat(document.get("name")).isEqualTo("value");
}

• Approved dynamic-class-loading pattern:

@Test
void loadsGeneratedHandlerClass() throws Exception {
    try {
        Class<?> handlerClass = compileAndLoadHandler();
        assertThat(HandlerRegistry.register(handlerClass).name()).isEqualTo("generated");
    } catch (Error e) {
        if (!NativeImageSupport.isUnsupportedFeatureError(e)) {
            throw e;
        }
        // Expected: Native Image cannot load generated classes discovered after build.
    }
}

• Bad version-pinned assertion:

@Test
void reportsVersion() {
    assertThat(LibraryVersion.current()).isEqualTo("1.2.3");
}