@codacy/tools-scalastyle-1

Table of Contents

• Overview
• Updating patterns
• Updating the Scalastyle version
• Development
• Notes for maintainers

Overview

Scala style checker and static analysis tool using the Scalastyle assembly JAR. Uses the CLI execution strategy -- spawns java -cp scalastyle.jar org.scalastyle.Main via spawnTool() and parses its Checkstyle-format XML output.

Scalastyle is primarily a Scala 2 tool. It parses Scala source files and checks for style violations, complexity issues, and potential bugs. The assembly JAR is hosted on Maven Central.

Updating patterns

# Re-fetch pattern metadata from the Codacy API
pnpm prefetch

# Commit the result
git add src/patterns.json

Pattern IDs follow the format ScalaStyle_MagicNumberChecker, ScalaStyle_FileLengthChecker, etc. Note the capital S in ScalaStyle and that the Checker suffix is retained (unlike Checkstyle which strips Check).

Updating the Scalastyle version

1. Update SCALASTYLE_VERSION in src/adapter.ts
2. Update JAR_URL to point to the new assembly JAR on Maven Central
3. Run pnpm prefetch to check for new/removed rules
4. Run pnpm test to verify compatibility
5. If the major version changes, create a new adapter package (scalastyle-2/)

The Maven Central artifact coordinates are:

com.beautiful-scala:scalastyle_2.13:{version}:assembly

Development

pnpm build    # Build with tsup
pnpm test     # Run tests (unit tests always run; integration tests require java + JAR)

To install the Scalastyle JAR locally for integration testing:

mkdir -p /tmp/codacy-scalastyle-test-tools
curl -L -O --output-dir /tmp/codacy-scalastyle-test-tools \
  https://repo1.maven.org/maven2/com/beautiful-scala/scalastyle_2.13/1.5.1/scalastyle_2.13-1.5.1-assembly.jar

The filename must be kept as published (scalastyle_2.13-<version>-assembly.jar) — the adapter's presence check is version-stamped, so a renamed JAR will not be found.

Notes for maintainers

• Scalastyle requires Java 8+ as a runtime. The adapter uses ensureJre() to download Adoptium Temurin JDK 21 if no system Java is found.
• The assembly JAR (~9 MB) is downloaded from Maven Central via downloadJar() to ~/.codacy/tools/scalastyle-1/.
• Scalastyle takes directories as input, not individual file lists. The adapter passes the repository root and then filters the XML output by ctx.targetFiles.
• XML output is written to a temp file via --xmlOutput, not to stdout. The adapter reads and parses the temp file after execution.
• The source attribute in XML output is an FQCN like org.scalastyle.scalariform.MagicNumberChecker. The adapter extracts the last segment to derive the pattern ID.
• Checker namespace mapping: checkers in the static FILE_LEVEL_CHECKERS set map to org.scalastyle.file.*; all others map to org.scalastyle.scalariform.*.
• Exit code 0 = clean, 1 = findings found or error. The adapter reads the XML output regardless of exit code (0 or 1).
• Config file detection looks for scalastyle_config.xml or scalastyle-config.xml in the repository root (underscore variant preferred).
• When generating config from patterns, each check is emitted with level="warning" and includes default parameters from patterns.json.
• The column attribute may be absent in Scalastyle output; it is omitted from the issue when not present.
• fast-xml-parser is configured with ignoreAttributes: false and isArray for file/error elements to handle single-element cases.