language-detect

Fast, evidence-based programming language detection for projects.

Philosophy

- Evidence-based - Shows WHY each language was detected (markers + file counts)
- Fast scanning - Checks markers first, falls back to extension counts
- Composable output - JSON pipes to jq, other tools, CI/CD
- Useful standalone - Debugging, scripts, tool integration

Installation

``bash


Install globally

cd packages/language-detect
bun link

Or run directly with bun

bun language-detect.ts /path/to/project
`

Usage

`bash


Detect languages in current directory

language-detect .

Detect in specific project

language-detect /path/to/project

List detected languages only

language-detect . | jq -r '.languages[]'

Show evidence for specific language

language-detect . | jq '.markers.typescript'

Check if project uses Go

language-detect . | jq -e '.languages[] | select(. == "go")'
`

Detection Strategy

$3

- Python: pyproject.toml, requirements.txt, setup.py, Pipfile
- JavaScript/TypeScript: package.json, tsconfig.json
- Go: go.mod, go.sum
- Rust: Cargo.toml, Cargo.lock
- Ruby: Gemfile, Gemfile.lock
- etc.

$3

- Counts files with language extensions (.ts, .py, .go, etc.)
- Configurable threshold (default: any files detected)
- Scans up to 3 directory levels deep
- Skips hidden directories for performance

Output Format

`json
{
"languages": ["typescript"],
"markers": {
"typescript": ["7 *.ts files"]
}
}
`

Supported Languages

- Python
- JavaScript
- TypeScript
- Go
- Rust
- Ruby
- Java
- C#
- PHP
- Swift
- Kotlin
- Scala

Configuration

Edit EXTENSION_THRESHOLD in language-detect.ts:
- 0 = detect any files (default)
- 3 = need 3+ files
- Higher values = more conservative detection

Exit Codes

- 0 - Success (languages detected or none found)
- 2` - Error (invalid args, directory not found)