Dotnet-skills playwright-ci-caching
Cache Playwright browser binaries in CI/CD pipelines (GitHub Actions, Azure DevOps) to avoid 1-2 minute download overhead on every build.
git clone https://github.com/Aaronontheweb/dotnet-skills
T=$(mktemp -d) && git clone --depth=1 https://github.com/Aaronontheweb/dotnet-skills "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/playwright-ci-caching" ~/.claude/skills/aaronontheweb-dotnet-skills-playwright-ci-caching && rm -rf "$T"
skills/playwright-ci-caching/SKILL.mdCaching Playwright Browsers in CI/CD
When to Use This Skill
Use this skill when:
- Setting up CI/CD for a project with Playwright E2E tests
- Build times are slow due to browser downloads (~400MB, 1-2 minutes)
- You want automatic cache invalidation when Playwright version changes
- Using GitHub Actions or Azure DevOps pipelines
The Problem
Playwright browsers (~400MB) must be downloaded on every CI run by default. This:
- Adds 1-2 minutes to every build
- Wastes bandwidth
- Can fail on transient network issues
- Slows down PR feedback loops
Core Pattern
- Extract Playwright version from
(CPM) to use as cache keyDirectory.Packages.props - Cache browser binaries using platform-appropriate paths
- Conditional install - only download on cache miss
- Automatic cache bust - key includes version, so package upgrades invalidate cache
Cache Paths by OS
| OS | Path |
|---|---|
| Linux | |
| macOS | |
| Windows | |
GitHub Actions
- name: Get Playwright Version shell: pwsh run: | $propsPath = "Directory.Packages.props" [xml]$props = Get-Content $propsPath $version = $props.Project.ItemGroup.PackageVersion | Where-Object { $_.Include -eq "Microsoft.Playwright" } | Select-Object -ExpandProperty Version echo "PlaywrightVersion=$version" >> $env:GITHUB_ENV - name: Cache Playwright Browsers id: playwright-cache uses: actions/cache@v4 with: path: ~/.cache/ms-playwright key: ${{ runner.os }}-playwright-${{ env.PlaywrightVersion }} - name: Install Playwright Browsers if: steps.playwright-cache.outputs.cache-hit != 'true' shell: pwsh run: ./build/playwright.ps1 install --with-deps
Multi-OS GitHub Actions
For workflows that run on multiple operating systems:
- name: Cache Playwright Browsers id: playwright-cache uses: actions/cache@v4 with: path: | ~/.cache/ms-playwright ~/Library/Caches/ms-playwright ~/AppData/Local/ms-playwright key: ${{ runner.os }}-playwright-${{ env.PlaywrightVersion }}
Azure DevOps
- task: PowerShell@2 displayName: 'Get Playwright Version' inputs: targetType: 'inline' script: | [xml]$props = Get-Content "Directory.Packages.props" $version = $props.Project.ItemGroup.PackageVersion | Where-Object { $_.Include -eq "Microsoft.Playwright" } | Select-Object -ExpandProperty Version Write-Host "##vso[task.setvariable variable=PlaywrightVersion]$version" - task: Cache@2 displayName: 'Cache Playwright Browsers' inputs: key: 'playwright | "$(Agent.OS)" | $(PlaywrightVersion)' path: '$(HOME)/.cache/ms-playwright' cacheHitVar: 'PlaywrightCacheHit' - task: PowerShell@2 displayName: 'Install Playwright Browsers' condition: ne(variables['PlaywrightCacheHit'], 'true') inputs: filePath: 'build/playwright.ps1' arguments: 'install --with-deps'
Helper Script: playwright.ps1
Create a
build/playwright.ps1 script that discovers and runs the Playwright CLI. This abstracts away the Playwright CLI location which varies by project structure.
# build/playwright.ps1 # Discovers Microsoft.Playwright.dll and runs the bundled Playwright CLI param( [Parameter(ValueFromRemainingArguments = $true)] [string[]]$Arguments ) # Find the Playwright DLL (after dotnet build/restore) $playwrightDll = Get-ChildItem -Path . -Recurse -Filter "Microsoft.Playwright.dll" -ErrorAction SilentlyContinue | Select-Object -First 1 if (-not $playwrightDll) { Write-Error "Microsoft.Playwright.dll not found. Run 'dotnet build' first." exit 1 } $playwrightDir = $playwrightDll.DirectoryName # Find the playwright CLI (path varies by OS and node version) $playwrightCmd = Get-ChildItem -Path "$playwrightDir/.playwright/node" -Recurse -Filter "playwright.cmd" -ErrorAction SilentlyContinue | Select-Object -First 1 if (-not $playwrightCmd) { # Try Unix executable $playwrightCmd = Get-ChildItem -Path "$playwrightDir/.playwright/node" -Recurse -Filter "playwright" -ErrorAction SilentlyContinue | Where-Object { $_.Name -eq "playwright" } | Select-Object -First 1 } if (-not $playwrightCmd) { Write-Error "Playwright CLI not found in $playwrightDir/.playwright/node" exit 1 } Write-Host "Using Playwright CLI: $($playwrightCmd.FullName)" & $playwrightCmd.FullName @Arguments
Usage:
# Install browsers ./build/playwright.ps1 install --with-deps # Install specific browser ./build/playwright.ps1 install chromium # Show installed browsers ./build/playwright.ps1 install --dry-run
Prerequisites
This pattern assumes:
-
Central Package Management (CPM) with
:Directory.Packages.props<Project> <ItemGroup> <PackageVersion Include="Microsoft.Playwright" Version="1.40.0" /> </ItemGroup> </Project> -
Project has been built before running
(so DLLs exist)playwright.ps1 -
PowerShell available on CI agents (pre-installed on GitHub Actions and Azure DevOps)
Why Version-Based Cache Keys Matter
Using the Playwright version in the cache key ensures:
- Automatic invalidation when you upgrade Playwright
- No stale browser binaries that don't match the SDK version
- No manual cache clearing needed after version bumps
If you hardcode the cache key (e.g.,
playwright-browsers-v1), you'll need to manually bump it every time you upgrade Playwright, or you'll get cryptic version mismatch errors.
Troubleshooting
Cache not being used
- Verify the version extraction step outputs the correct version
- Check that the cache path matches your OS
- Ensure
exists and has the Playwright packageDirectory.Packages.props
"Browser not found" after cache hit
The cached browsers don't match the Playwright SDK version. This happens when:
- The cache key doesn't include the version
- The version extraction failed silently
Fix: Ensure the Playwright version is in the cache key.
playwright.ps1 can't find the DLL
Run
dotnet build or dotnet restore before running the script. The Playwright DLL only exists after NuGet restore.
References
This pattern is battle-tested in production projects:
Related Skills
- Writing Playwright tests for Blazor applicationsdotnet-skills:playwright-blazor
- Central Package Management setupdotnet-skills:project-structure