vscode/.github/workflows/node_modules_cache

node_modules cache scripts

Shared helpers used by the GitHub Actions workflows to store and restore the node_modules cache. They exist so the archive format and compression flags live in a single place instead of being duplicated across every workflow.

Each script takes an action argument:

Script	Platform	archive	extract
cache.sh <action>	Linux / macOS	Create node-modules.tzst (cache miss)	Restore node-modules.tzst (cache hit)
cache.ps1 <action>	Windows	Create cache.7z (cache miss)	Restore cache.7z (cache hit)

Linux/macOS use multi-threaded zstd (node-modules.tzst); Windows uses 7-Zip (cache.7z). The archive must NOT be named cache.tzst: actions/cache names its own tarball cache.tzst and passes --exclude cache.tzst, which would drop our archive and save an empty cache. The two families are not interchangeable, so the cache key already encodes the OS (node_modules-linux-*, node_modules-windows-*, …).

Example usage from a workflow step:

- name: Extract node_modules cache
  if: steps.cache-node-modules.outputs.cache-hit == 'true'
  run: ./.github/workflows/node_modules_cache/cache.sh extract

- name: Create node_modules archive
  if: steps.cache-node-modules.outputs.cache-hit != 'true'
  run: ./.github/workflows/node_modules_cache/cache.sh archive

If you change the archive format or flags, update both the archive and extract branch of the script, and bump build/.cachesalt to invalidate existing caches.

Electron download cache

The platform jobs in pr-node-modules.yml also warm a separate Electron download cache on main. The setup-electron action shares cache handling and download retries with the Linux, macOS, and Windows PR test workflows:

• By default, restore cached archives and validate/prepare Electron, downloading with up to three attempts as needed. PR jobs use this mode without saving.
• lookup-only: 'true' only checks for a cache entry, without restoring archives, preparing Electron, or saving. This mode does not require npm dependencies.
• save-cache: 'true' also saves after successful setup on a cache miss.

The cache stores @electron/get's original download archives, not the prepared .build/electron application. Its key includes the runner OS, target architecture, and a hash of .npmrc and build/checksums/electron.txt. Ordinary package-lock.json changes do not invalidate it. If a downloader update changes the cache format, bump the electron-download-v1 prefix in setup-electron.

The paths match @electron/get's platform defaults, including XDG_CACHE_HOME on Linux and LOCALAPPDATA on Windows. Cache paths and keys are handled within the action.

Even on a cache hit, PR jobs run npm run electron to validate and prepare the application from the cached archives using the current checkout. Checksum validation remains enabled: the current downloader still fetches SHASUMS256.txt from GitHub, so this cache avoids the large ZIP downloads but does not make Electron setup entirely network-independent.

On main, an Electron cache hit uses lookup-only checks and skips downloading Electron. On a miss, the platform job restores node_modules (or installs them if that cache also misses), then invokes setup-electron with save-cache: 'true'. This checks the cache again before preparing and saving Electron, while keeping already-warm jobs from extracting dependency archives unnecessarily.