Java

What is planned

When the built-in Java runner ships, it will:

Accept lang: java in nolapse.yaml.
Support both Maven (mvn test) and Gradle (./gradlew test) build systems automatically.
Parse JaCoCo XML or CSV reports to extract overall instruction or line coverage.
Respect the same warn_threshold / fail_threshold / strict_mode settings as all other runners.

The expected nolapse.yaml when it is available:

lang: java
warn_threshold: -1.0
fail_threshold: -5.0
strict_mode: false

Workaround: custom runner (Maven + JaCoCo)

Until the built-in runner ships you can parse JaCoCo output yourself and emit the result in the format nolapse expects.

1. Add the JaCoCo plugin

In your pom.xml:

<plugin>
  <groupId>org.jacoco</groupId>
  <artifactId>jacoco-maven-plugin</artifactId>
  <version>0.8.11</version>
  <executions>
    <execution>
      <goals><goal>prepare-agent</goal></goals>
    </execution>
    <execution>
      <id>report</id>
      <phase>test</phase>
      <goals><goal>report</goal></goals>
    </execution>
  </executions>
</plugin>

2. Write a custom runner script

Create nolapse-runner.sh at the repo root:

#!/usr/bin/env bash
set -euo pipefail

REPO_PATH="${1:-.}"
cd "$REPO_PATH"

mvn -q test

# Parse JaCoCo CSV: covered / (covered + missed) for INSTRUCTION
CSV="target/site/jacoco/jacoco.csv"
PCT=$(tail -n +2 "$CSV" | awk -F',' '
  { covered += $5; missed += $4 }
  END { printf "%.1f", (covered / (covered + missed)) * 100 }
')

echo "nolapse-coverage: ${PCT}"

Make it executable:

chmod +x nolapse-runner.sh

3. Configure nolapse

lang: custom
warn_threshold: -1.0
fail_threshold: -5.0

Run nolapse:

NOLAPSE_RUNNER_PATH=./nolapse-runner.sh nolapse run --repo .

See Custom Runner for the full runner contract.

Workaround: Gradle + JaCoCo

For Gradle projects, replace the Maven step in the runner script with:

./gradlew test jacocoTestReport
CSV="build/reports/jacoco/test/jacocoTestReport.csv"

The CSV parsing awk expression is the same.

Track the roadmap

Watch the nolapse changelog and the Java runner issue for updates.