Java Coverage

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Run JaCoCo against a scoped (or full) test run via mvn clean jacoco:prepare-agent test jacoco:report, then read the generated target/site/jacoco/jacoco.csv to report the exact, measured line-coverage percentage for the specific class(es) the caller cares about. This is a read-only reporting skill: it measures and reports coverage, it does not add tests or modify source/test code unless asked to as an explicit follow-up.

Purpose

iru-java-coverage answers "does class X meet the coverage bar?" with an exact, CSV-derived percentage instead of an eyeballed guess from Surefire output. It reuses `iru-java-test’s selector syntax to scope which tests run, infers or accepts an explicit list of target classes, and — for classes under the bar — points to the exact uncovered lines/branches in the per-class HTML report so a follow-up can target them precisely.

Purpose group

Java Development Tooling

Invocation

/iru-java-coverage
/iru-java-coverage <selector> [TargetClass1,TargetClass2,...]

Inputs

Argument Required Description Default

selector

No

Which tests to run, using the exact same syntax as the iru-java-test skill’s selector table (class, class+method, comma list, wildcard, package pattern, tag expression). Must cover every test class that exercises the target class(es) — a selector scoped too narrowly undercounts real coverage, so a broader selector (a whole package, or the full suite) is preferred when in doubt.

None — omitting it runs the full suite.

TargetClass1,TargetClass2,…​

No

Comma-separated class name(s) to report coverage for.

None — if omitted, target classes are inferred from the test selector by convention (FooTest → Foo), or, for a wildcard/package/tag selector where no name can be inferred, every class touched by the run is reported (or the user is asked which class(es) matter).

Outputs

  • A plain-text summary in the conversation — never a written file.

  • Per target class: exact line-coverage percentage (and branch coverage where relevant), computed directly from target/site/jacoco/jacoco.csv — never estimated.

  • If the user gave a coverage bar (e.g. "at least 80%"): a clear statement of whether each class meets it.

  • For classes under the bar: a pointer to the per-class HTML/.java.html report and the exact uncovered line numbers (via the nc/pc/fc span classes) rather than just the aggregate percentage.

  • A class absent from the CSV is reported as 0% coverage, not as an error.

  • No source or test code is ever modified, and coverage is never re-run to try to raise a number.

Execution flow

flowchart TD A["Start /java-coverage\n(optional selector, target classes)"] --> B{Selector given?} B -- yes --> C["Scope tests using java-test's\nselector syntax"] B -- no --> D["Run full suite"] C --> E D --> E{Target classes given?} E -- yes --> F["Use given class list"] E -- no --> G["Infer from test selector\n(FooTest -> Foo), or defer to\nevery class touched by the run"] F --> H["Run mvn clean jacoco:prepare-agent\ntest jacoco:report -Dtest=<selector>"] G --> H H --> I{Build succeeded?} I -- no --> J["Report failure, stop\n(don't read a stale report)"] I -- yes --> K["Read target/site/jacoco/jacoco.csv"] K --> L["Compute line / branch / instruction\ncoverage % per target class"] L --> M{Class row found in CSV?} M -- no --> N["Report 0% (not an error)"] M -- yes --> O["Report exact %; state pass/fail\nvs. any given bar"] N --> P O --> P{Under the bar?} P -- yes --> Q["Point to per-class HTML +\n.java.html for uncovered lines"] P -- no --> R["State it meets the bar"]

Dependencies

Invokes

None — iru-java-coverage is a leaf skill; it only runs Maven commands and reads the generated JaCoCo reports, it does not call any other skill in this catalog.

Invoked by

  • Java Code One Task Group — Step 3, once per task group’s bucket, via the iru-gate-runner agent, to check every changed/new class in the bucket meets the 80% coverage bar (falling back to mvn jacoco:prepare-agent test jacoco:report directly if this skill is unavailable).

Related agents

Source

SKILL.md on GitHub — the file this page was generated from.