@codacy/tools-detekt-1

Table of Contents

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

Overview

Kotlin static analyzer using the detekt CLI JAR. Uses the CLI execution strategy -- spawns java -jar detekt-cli-all.jar via spawnTool() and parses its Checkstyle XML output.

Updating patterns

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

# Commit the result
git add src/patterns.json

Pattern IDs are bare rule names (no prefix): LongMethod, MagicNumber, ComplexCondition, etc.

Updating the detekt version

1. Update DETEKT_VERSION and JAR_NAME in src/adapter.ts
2. Update JAR_URL to point to the new release
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 (detekt-2/)

Development

pnpm build    # Build with tsup
pnpm test     # Run tests (requires java in PATH + detekt JAR)

To install detekt locally for testing:

# Download the all-in-one JAR
curl -L -o /tmp/codacy-detekt-test-tools/detekt-cli-1.23.8-all.jar \
  https://github.com/detekt/detekt/releases/download/v1.23.8/detekt-cli-1.23.8-all.jar

Notes for maintainers

• Preset mappings (src/pattern-mappings.json): the seven coroutines rules are gated on kotlinx-coroutines, detected from any kotlinx-coroutines-* Maven artifact. All seven are default-off upstream, so before this they could never be enabled by init --auto — not even in a coroutines project. Five carry detekt's own coroutines tag; GlobalCoroutineUsage and InjectDispatcher carry no tag and are matched by their bare rule name (detekt pattern IDs have no tool prefix).

• detekt requires Java 8+ as a runtime. The adapter uses ensureJre() to download Adoptium Temurin JDK 21 if no system Java is found.

• The detekt CLI JAR is an all-in-one fat JAR downloaded from GitHub releases to ctx.toolInstallDir.

• Output format is Checkstyle 4.3 XML written to a temp file via --report xml:<path>.

• --base-path <repoRoot> ensures file paths in the XML are relative to the repository root.

• --parallel enables multi-threaded analysis for performance.

• The source attribute in XML has format detekt.RuleName or detekt.ruleset.RuleName. The adapter strips the detekt. prefix and any ruleset prefix to get just the rule name.

• Pattern IDs in patterns.json have no prefix -- they are bare rule names (e.g. LongMethod, not detekt_LongMethod).

• Exit codes: 0 = no findings, 1 = findings found (build failure threshold), 2 = findings found, 3 = invalid config.

• Config file detection supports detekt.yml and default-detekt-config.yml. When a local config is found, it is passed via --config <path>.

• Pattern filtering is post-hoc: detekt runs with all default rules, then output is filtered by the enabled patterns set.