detect-language

Language Detection Skill

Goal

Autonomously detect the programming language, framework, build tools, and verification commands for ANY project.

When to Use

• User asks: "What language is this project?"
• Initializing ralph-dev for a new project
• User runs: /detect-language

---

Workflow

Step 0: Initialize CLI (Automatic)

IMPORTANT: This skill requires the Ralph-dev CLI. It will build automatically on first use.

# Bootstrap CLI - runs automatically, builds if needed
source ${CLAUDE_PLUGIN_ROOT}/shared/bootstrap-cli.sh

# Verify CLI is ready
ralph-dev --version

Step 1: Scan Project Structure

# List root files
ls -la

# Find config files (depth 2)
find . -maxdepth 2 -type f \( \
  -name 'package.json' -o -name '*.toml' -o -name '*.gradle' \
  -o -name 'pom.xml' -o -name 'Gemfile' -o -name 'go.mod' \
  -o -name '*.csproj' -o -name 'Makefile' -o -name 'Package.swift' \
\) 2>/dev/null

# Count source files by extension
for ext in ts js py go rs java rb php cs cpp swift; do
  count=$(find . -name "*.$ext" -type f 2>/dev/null | wc -l)
  [ "$count" -gt 0 ] && echo "$ext: $count files"
done

Step 2: Analyze Config Files

Read the primary config file for the detected language and extract:

• Dependencies and devDependencies
• Scripts/commands available
• Framework indicators

Step 3: Determine Stack

Based on evidence, identify:

Component	How to Detect
Language	Primary config file + file extensions
Framework	Check dependencies for react, django, express, etc.
Build Tool	Config files: vite.config, webpack.config, Cargo.toml
Package Manager	Lock files: pnpm-lock.yaml, yarn.lock, go.sum
Test Framework	devDependencies: jest, vitest, pytest

Step 4: Generate Verification Commands

Language → Commands Mapping:

Language	Type Check	Lint	Test	Build
TypeScript	npx tsc --noEmit	npm run lint	npm test	npm run build
Python	mypy .	flake8	pytest	-
Go	-	go vet ./...	go test ./...	go build ./...
Rust	-	cargo clippy	cargo test	cargo build
Java (Maven)	-	-	mvn test	mvn package
Java (Gradle)	-	-	./gradlew test	./gradlew build
Ruby	-	rubocop	rspec	-
C#	-	-	dotnet test	dotnet build

Adapt commands based on actual project config (scripts in package.json, etc.)

Step 5: Save Results

# Build JSON result
RESULT='{ "language": "...", "verifyCommands": [...] }'

# Save using CLI
ralph-dev detect-ai-save "$RESULT"

Step 6: Display Summary

✅ Language Detection Complete

Language: {language}
Framework: {framework}
Build Tool: {buildTool}
Package Manager: {packageManager}
Test Framework: {testFramework}
Confidence: {N}%

Verification Commands:
1. {typecheck command}
2. {lint command}
3. {test command}
4. {build command}

---

Output Format

{
  "language": "typescript",
  "confidence": 0.95,
  "evidence": ["package.json exists", "tsconfig.json exists", "47 .ts files"],
  "framework": "react",
  "buildTool": "vite",
  "packageManager": "pnpm",
  "testFramework": "vitest",
  "verifyCommands": [
    "npx tsc --noEmit",
    "pnpm run lint",
    "pnpm test",
    "pnpm run build"
  ]
}

---

Edge Cases

Monorepo: Multiple config files in subdirectories

• Detect as monorepo, list packages with their languages
• Generate per-package verification commands

Multi-Language: Significant files from multiple languages

• Identify primary language
• Note secondary languages
• Generate commands for each

Custom Build: No recognized build system

• Lower confidence score
• Check for Makefile targets
• Suggest manual configuration

---

Constraints

• NEVER assume without evidence - always scan files first
• NEVER suggest commands for tools not present in project
• ALWAYS base confidence on concrete file presence
• ALWAYS adapt commands to project's actual scripts/config
• ALWAYS handle edge cases (monorepo, multi-language)

---

Error Handling

Error	Action
No config files found	Lower confidence, detect from file extensions
Conflicting indicators	Note ambiguity, ask user to clarify
Unknown build system	Suggest manual configuration