Debug CI

Debug CI

Reproduce CI test failures locally using a Docker container that mirrors the CI environment.

When to Use

• CI job fails but the same tests pass locally on macOS/Windows
• VSCode extension tests fail (require xvfb + Linux GUI libraries)
• Platform-specific issues (Linux vs macOS vs Windows)

CI Jobs Overview

Reference: .github/workflows/ci.yml

Workflow

Step 1: Identify the Failing Job

gh pr checks <PR_NUMBER>

Fetch detailed failure logs:

# Find failed job IDs
gh api repos/web-infra-dev/rslint/actions/runs/<RUN_ID>/jobs \
  --jq '.jobs[] | select(.conclusion == "failure") | {name, id}'

# Get logs for a specific job
gh api repos/web-infra-dev/rslint/actions/jobs/<JOB_ID>/logs

Step 2: Build Docker Image

Check current tool versions from CI config before building:

Write a Dockerfile. The apt packages for xvfb must match the CI step in test-node:

# From CI: sudo apt install -y libasound2 libgbm1 libgtk-3-0 libnss3 xvfb

Additional GUI dependencies (libxss1, libatk-bridge2.0-0, etc.) are needed for VSCode Electron to run headlessly — they are implicit in the CI runner image but not in bare ubuntu:22.04.

Complete Dockerfile:

FROM ubuntu:22.04

ENV DEBIAN_FRONTEND=noninteractive
ENV GOMAXPROCS=8

# Base tools
RUN apt-get update && apt-get install -y \
    curl wget git build-essential \
    && rm -rf /var/lib/apt/lists/*

# xvfb and GUI deps (from ci.yml test-node job + Electron implicit deps)
RUN apt-get update && apt-get install -y \
    libasound2 libgbm1 libgtk-3-0 libnss3 xvfb \
    libxss1 libatk-bridge2.0-0 libdrm2 libxcomposite1 libxdamage1 libxrandr2 \
    libpango-1.0-0 libcairo2 libcups2 libdbus-1-3 libexpat1 libfontconfig1 \
    libgcc1 libglib2.0-0 libnspr4 libpangocairo-1.0-0 libstdc++6 libx11-6 \
    libx11-xcb1 libxcb1 libxcursor1 libxfixes3 libxi6 libxrender1 libxtst6 \
    ca-certificates fonts-liberation lsb-release xdg-utils \
    && rm -rf /var/lib/apt/lists/*

# Go (version from ci.yml go-version matrix)
RUN curl -fsSL https://go.dev/dl/go1.25.0.linux-amd64.tar.gz | tar -C /usr/local -xz
ENV PATH="/usr/local/go/bin:${PATH}"
ENV GOPATH="/root/go"
ENV PATH="${GOPATH}/bin:${PATH}"

# Node (version from .github/actions/setup-node/action.yml)
RUN curl -fsSL https://deb.nodesource.com/setup_24.x | bash - \
    && apt-get install -y nodejs \
    && rm -rf /var/lib/apt/lists/*

# pnpm (from .github/actions/setup-node/action.yml: corepack enable)
RUN corepack enable

# golangci-lint (version from ci.yml lint job → golangci-lint-action)
RUN curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/HEAD/install.sh \
    | sh -s -- -b /usr/local/bin v2.4.0

WORKDIR /workspace

Build:

docker build -t rslint-ci-test <dockerfile-dir>

Step 3: Write Test Script

Choose the test script based on which CI job failed:

Test npm packages (Linux) — the most common scenario requiring Docker reproduction:

#!/bin/bash
set -e
cd /workspace

rm -rf node_modules packages/*/node_modules
find . -name '.vscode-test' -type d -exec rm -rf {} + 2>/dev/null || true

pnpm install --frozen-lockfile    # .github/actions/setup-node
pnpm format:check                 # ci.yml test-node "Format" (Linux only)
pnpm run build                    # ci.yml test-node "Build" step
pnpm run lint --format github     # ci.yml test-node "Dogfooding" (Linux only)
pnpm typecheck                    # ci.yml test-node "TypeCheck" (Linux only)
xvfb-run -a pnpm run test         # ci.yml test-node "Test on Linux" step

Lint&Check:

#!/bin/bash
set -e
cd /workspace
rm -rf node_modules packages/*/node_modules
pnpm install --frozen-lockfile
golangci-lint run --timeout=5m ./cmd/... ./internal/...   # ci.yml lint "golangci-lint"
npm run lint:go                                           # ci.yml lint "go vet"
npm run format:go                                         # ci.yml lint "go fmt"
pnpm check-spell                                         # ci.yml lint "Check Spell"

Test Go (Linux):

#!/bin/bash
set -e
cd /workspace
go test -parallel 8 ./internal/...   # ci.yml test-go "Unit Test"

Test WASM:

#!/bin/bash
set -e
cd /workspace
rm -rf node_modules packages/*/node_modules
pnpm install --frozen-lockfile
pnpm --filter '@rslint/core' build:js
pnpm --filter '@rslint/wasm' build   # ci.yml test-wasm "Build"

Build Website:

#!/bin/bash
set -e
cd /workspace
rm -rf node_modules packages/*/node_modules
pnpm install --frozen-lockfile
pnpm run build:website               # ci.yml website "Build"

Step 4: Run in Docker

docker run --rm \
  -v <project-root>:/workspace \
  -v <test-script>:/run-test.sh:ro \
  rslint-ci-test bash /run-test.sh

Step 5: Restore Host Environment

Docker overwrites host node_modules and Go binaries with Linux versions. Always restore after testing:

pnpm install

Caveats

• typescript-go submodule ~1.2GB: Do not cp / rsync the project inside the container — use a bind mount directly
• Apple Silicon: Docker runs via x86_64 emulation, Go compilation will be 5-10x slower
• node_modules conflict: The container installs Linux-native dependencies, overwriting macOS/Windows host dependencies. Always run pnpm install after testing to restore
• Windows CI: Docker cannot simulate a Windows runner. Windows-specific failures require a Windows machine to debug
• Test Rust: CI runs on macOS, not suitable for Linux Docker reproduction

Source: web-infra-dev/rslint — distributed by TomeVault.