eia-multilanguage-pr-review

Multilanguage PR Review Skill

Overview

Modern repositories often contain code in multiple programming languages. A single repository might have:

• A Python backend with FastAPI
• A TypeScript frontend with React
• Rust binaries for performance-critical operations
• Go microservices
• Bash scripts for automation and CI/CD

Reviewing PRs in such repositories requires understanding which languages are affected and applying the appropriate review standards for each.

Prerequisites

• GitHub CLI (gh) installed and authenticated
• Python 3.8+ for running detection scripts
• Language-specific linters installed (ruff, mypy, ESLint, clippy, etc.)
• Git for local diff analysis

Output

Output Type	Format	Description
Language Detection Report	JSON	List of detected languages with file counts and lines changed per language
Linter Recommendations	JSON	Recommended linters, install commands, and run commands for each detected language
Review Summary	Markdown	Comprehensive review findings organized by language with cross-language impact analysis
Linter Results	Text/JSON	Aggregated output from all language-specific linters (ruff, ESLint, clippy, etc.)

Instructions

1. Run eia_detect_pr_languages.py to identify all programming languages affected by the PR
2. For each detected language, read the corresponding review patterns document from the references directory
3. Execute eia_get_language_linters.py to obtain the appropriate linters and their commands for each language
4. Run all recommended linters against the changed files in their respective languages
5. Check for cross-language interface changes (API contracts, FFI boundaries, shared configuration)
6. Verify platform-specific code paths have appropriate guards and tests (see cross-platform-testing.md)
7. Compile linter results and findings into a comprehensive review summary organized by language
8. Write the final review comment with language-specific findings and cross-language impact analysis

Challenges of Multilanguage Repositories

1. Different coding standards: Each language has its own conventions for naming, formatting, and structure
2. Different testing frameworks: pytest for Python, Jest for JavaScript, cargo test for Rust
3. Different linting tools: ruff/mypy for Python, ESLint for JavaScript, Clippy for Rust
4. Cross-language interfaces: FFI boundaries, API contracts, data serialization
5. Platform-specific code: Code paths that only run on certain operating systems

When to Use This Skill

Use this skill when:

• Reviewing a PR that touches files in multiple programming languages
• Setting up review workflows for a polyglot repository
• Determining which linters and checkers to run for changed files
• Coordinating cross-language interface reviews

Quick Reference: Language Detection

For detailed language detection methods, see language-detection.md:

• 1.1 Detecting language from file extensions
• 1.2 Detecting language from shebang lines
• 1.3 Using .gitattributes linguist hints
• 1.4 Understanding GitHub's language detection algorithm
• 1.5 Handling mixed-language files

Quick Reference: Language-Specific Review Patterns

Python Reviews

See python-review-patterns.md:

• 2.1 Python code style and formatting checklist
• 2.2 Type hints verification and mypy compliance
• 2.3 Docstring standards (Google, NumPy, Sphinx)
• 2.4 Import organization and dependency management
• 2.5 Test framework patterns with pytest
• 2.6 Linting with ruff, mypy, and bandit

JavaScript/TypeScript Reviews

See javascript-review-patterns.md:

• 3.1 JavaScript/TypeScript code style checklist
• 3.2 Type safety patterns in TypeScript
• 3.3 Module system considerations (ESM vs CommonJS)
• 3.4 Test framework patterns with Jest and Vitest
• 3.5 Linting with ESLint and Prettier

Rust Reviews

See rust-review-patterns.md:

• 4.1 Rust code style and idioms checklist
• 4.2 Memory safety patterns and ownership
• 4.3 Error handling with Result and Option
• 4.4 Clippy lints and configuration
• 4.5 Documentation standards with rustdoc

Go Reviews

See go-review-patterns.md:

• 5.1 Go code style and idioms checklist
• 5.2 Error handling patterns in Go
• 5.3 Package organization and naming
• 5.4 Test patterns with go test
• 5.5 Linting with golint, go vet, and staticcheck

Shell Script Reviews

See shell-review-patterns.md:

• 6.1 Bash/Shell script review checklist
• 6.2 POSIX compatibility requirements
• 6.3 ShellCheck lints and fixes
• 6.4 Cross-platform considerations for macOS and Linux

Quick Reference: Cross-Platform Testing

See cross-platform-testing.md:

• 7.1 Testing on multiple operating systems
• 7.2 CI matrix configuration for GitHub Actions
• 7.3 Platform-specific test skips and annotations
• 7.4 Using Docker for reproducible builds

Decision Tree: PR Review Approach

START: New PR to review
  |
  v
[1] Run eia_detect_pr_languages.py to identify languages
  |
  v
[2] For each detected language:
  |
  +---> Is it Python? ---> Read python-review-patterns.md, run ruff + mypy
  |
  +---> Is it JavaScript/TypeScript? ---> Read javascript-review-patterns.md, run ESLint
  |
  +---> Is it Rust? ---> Read rust-review-patterns.md, run cargo clippy
  |
  +---> Is it Go? ---> Read go-review-patterns.md, run go vet + staticcheck
  |
  +---> Is it Bash/Shell? ---> Read shell-review-patterns.md, run ShellCheck
  |
  v
[3] Check for cross-language interfaces:
  |
  +---> API contracts between services? ---> Verify schema compatibility
  |
  +---> FFI boundaries? ---> Check type mappings and safety
  |
  +---> Shared configuration? ---> Ensure consistency
  |
  v
[4] Check for platform-specific code:
  |
  +---> Multiple OS targets? ---> Read cross-platform-testing.md
  |
  v
[5] Run eia_get_language_linters.py for each language to get linter commands
  |
  v
[6] Execute all linters and compile results
  |
  v
[7] Write review summary with findings per language
  |
  v
END

Included Scripts

eia_detect_pr_languages.py

Detects programming languages in a PR's changed files.

Usage:

# Detect languages in PR #123
python scripts/eia_detect_pr_languages.py --repo owner/repo --pr 123

# Detect languages in local diff
python scripts/eia_detect_pr_languages.py --diff-file changes.diff

Output: JSON with language breakdown and file counts.

eia_get_language_linters.py

Returns recommended linters and commands for a given language.

Usage:

# Get linters for Python
python scripts/eia_get_language_linters.py --language python

# Get linters for multiple languages
python scripts/eia_get_language_linters.py --languages python,javascript,rust

Output: JSON with linter names, install commands, and run commands.

Workflow Example

When reviewing a PR in a multilanguage repository:

# Step 1: Detect languages in the PR
python scripts/eia_detect_pr_languages.py --repo myorg/myrepo --pr 456

# Example output:
# {
#   "languages": {
#     "python": {"files": 12, "lines_changed": 450},
#     "typescript": {"files": 5, "lines_changed": 200},
#     "bash": {"files": 2, "lines_changed": 50}
#   },
#   "primary_language": "python"
# }

# Step 2: Get linters for detected languages
python scripts/eia_get_language_linters.py --languages python,typescript,bash

# Example output:
# {
#   "python": {
#     "linters": ["ruff", "mypy"],
#     "commands": {
#       "ruff": "ruff check .",
#       "mypy": "mypy --strict ."
#     }
#   },
#   ...
# }

# Step 3: Read the appropriate review patterns for each language
# Step 4: Run linters and compile results
# Step 5: Write comprehensive review

Common Pitfalls

1. Ignoring generated files: Many repos have generated code (protobuf, OpenAPI). Identify and skip these.
2. Over-linting vendored code: Third-party vendored code should be excluded from linting.
3. Missing cross-language impacts: A Python change might break a TypeScript client consuming its API.
4. Platform assumptions: Code working on Linux might fail on macOS due to path handling.
5. Different Python versions: A repo might support Python 3.8-3.12 with different type hint syntax.

Examples

Example 1: Detect Languages and Run Linters

# Detect languages in PR
python scripts/eia_detect_pr_languages.py --repo myorg/myrepo --pr 456
# Output: {"languages": {"python": {"files": 12}, "typescript": {"files": 5}}}

# Get recommended linters
python scripts/eia_get_language_linters.py --languages python,typescript
# Output: {"python": {"linters": ["ruff", "mypy"]}, "typescript": {"linters": ["eslint"]}}

# Run linters for each language
ruff check src/python/
eslint src/typescript/

Example 2: Cross-Language API Review

# Detect languages
python scripts/eia_detect_pr_languages.py --repo myorg/myrepo --pr 789

# If both Python (backend) and TypeScript (frontend) changed,
# verify API contracts are consistent between them
# Check OpenAPI/JSON schema compatibility

Error Handling

Problem: Language detection returns unexpected results

Solution: Check .gitattributes for linguist overrides. Some files may be marked with linguist-language or linguist-detectable=false.

Problem: Linter fails to run

Solution: Ensure the linter is installed. Use eia_get_language_linters.py to get install commands.

Problem: Too many linting errors

Solution: For legacy codebases, consider using --fix flags where available (ruff --fix, eslint --fix) and reviewing the automated fixes.

Problem: Cross-platform test failures

Solution: Read cross-platform-testing.md section 7.3 for platform-specific skip annotations.

Checklist: Multilanguage PR Review

Copy this checklist and track your progress:

• Detect all languages in the PR using eia_detect_pr_languages.py
• Read the review patterns document for each detected language
• Run appropriate linters for each language
• Check for cross-language interface changes
• Verify platform-specific code has appropriate guards
• Ensure tests exist for new functionality in each language
• Check CI configuration covers all affected languages
• Verify documentation is updated if public APIs changed

Resources

• references/language-detection.md - Language detection methods
• references/python-review-patterns.md - Python review checklist
• references/javascript-review-patterns.md - JavaScript/TypeScript review
• references/rust-review-patterns.md - Rust review checklist
• references/go-review-patterns.md - Go review checklist
• references/shell-review-patterns.md - Shell script review
• references/cross-platform-testing.md - Multi-OS testing