Add actions/setup-node@v4.0.2

docs/adrs/0000-caching-dependencies.md

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+# 0. Caching dependencies
+Date: 2021-05-21
+
+Status: Accepted
+
+# Context
+`actions/setup-node` is the 2nd most popular action in GitHub Actions. A lot of customers use it in conjunction with [actions/cache](https://github.com/actions/cache) to speed up dependencies installation.  
+See more examples on proper usage in [actions/cache documentation](https://github.com/actions/cache/blob/main/examples.md#node---npm).
+
+# Goals & Anti-Goals
+Integration of caching functionality into `actions/setup-node` action will bring the following benefits for action users:
+- Decrease the entry threshold for using the cache for Node.js dependencies and simplify initial configuration
+- Simplify YAML pipelines because no need additional steps to enable caching
+- More users will use cache for Node.js so more customers will have fast builds!
+
+We will add support for NPM and Yarn dependencies caching.  
+As the first stage, we won't support custom locations for `package-lock.json`, `yarn.lock` files and action will work only when files are located in repository root. 
+
+We don't pursue the goal to provide wide customization of caching in scope of `actions/setup-node` action. The purpose of this integration is covering ~90% of basic use-cases. If user needs flexible customization, we should advice them to use `actions/cache` directly.
+
+# Decision
+- Add `cache` input parameter to `actions/setup-node`. For now, input will accept the following values: 
+  - `npm` - enable caching for npm dependencies
+  - `yarn` - enable caching for yarn dependencies
+  - `''` - disable caching (default value)
+- Cache feature will be disabled by default to make sure that we don't break existing customers. We will consider enabling cache by default in next major release (`v3`)
+- Action will try to search `package-lock.json` or `yarn.lock` (npm 7.x supports `yarn.lock` files) files in the repository root and throw error if no one is found
+- The hash of found file will be used as cache key (the same approach like [actions/cache](https://github.com/actions/cache/blob/main/examples.md#node---npm) recommends)
+- The following key cache will be used `${{ runner.os }}-npm-${{ hashFiles('<package-lock-path>') }}`
+- Action will cache global cache:
+  - Npm (retrieved via `npm config get cache`)
+  - Yarn 1 (retrieved via `yarn cache dir`)
+  - Yarn 2 (retrieved via `yarn config get cacheFolder`)
+
+# Example of real use-cases
+Npm package manager:
+```yml
+steps:
+- uses: actions/checkout@v2
+- uses: actions/setup-node@v2
+  with:
+    node-version: '14'
+    cache: npm
+```
+
+Yarn package manager:
+```yml
+steps:
+- uses: actions/checkout@v2
+- uses: actions/setup-node@v2
+  with:
+    node-version: '14'
+    cache: yarn
+```
+
+# Release process
+
+As soon as functionality is implemented, we will release minor update of action. No need to bump major version since there are no breaking changes for existing users.
+After that, we will update [starter-workflows](https://github.com/actions/starter-workflows/blob/main/ci/node.js.yml) and [GitHub Action documentation](https://docs.github.com/en/actions/guides/building-and-testing-nodejs#example-caching-dependencies).

docs/adrs/0001-support-caching-deps-for-monorepos.md

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+# 0. Support caching dependencies for mono repos
+Date: 2021-07-13
+
+Status: Proposed
+
+## Context
+Currently, `actions/setup-node` supports caching dependencies for Npm and Yarn package managers.  
+For the first iteration, we have decided to not support cases where `package-lock.json` / `yarn.lock` are located outside of repository root.  
+Current implementation searches the following file patterns in the repository root: `package-lock.json`, `yarn.lock` (in order of resolving priorities)
+
+Obviously, it made build-in caching unusable for mono-repos and repos with complex structure.  
+We would like to revisit this decision and add customization for dependencies lock file location.
+
+## Proposal
+We have the following options:
+1. Allow to specify  directory where `package-lock.json` or `yarn.lock` are located
+2. Allow to specify path to the dependencies lock file (including directory path and filename)
+
+The second option looks more generic because it allows to:
+- specify multiple dependencies files using file patterns like `**/package-lock.json` ([one of recommended approaches in actions/cache](https://github.com/actions/cache/blob/main/examples.md#macos-and-ubuntu))
+- specify custom dependencies files like `src/npm-shrinkwrap.json`
+- change default resolving priority if both `yarn.lock` and `package-lock.json` exist in repository
+
+## Decision
+
+Add `cache-dependency-path` input that will accept path (relative to repository root) to dependencies lock file.  
+If provided path contains wildcards, the action will search all maching files and calculate common hash like `${{ hashFiles('**/package-lock.json') }}` YAML construction does.  
+The hash of provided matched files will be used as a part of cache key.
+
+Yaml examples:
+```yml
+steps:
+- uses: actions/checkout@v2
+- uses: actions/setup-node@v2
+  with:
+    node-version: 14
+    cache: npm
+    cache-dependency-path: 'sub-project/package-lock.json'
+```
+```yml
+steps:
+- uses: actions/checkout@v2
+- uses: actions/setup-node@v2
+  with:
+    node-version: 14
+    cache: yarn
+    cache-dependency-path: 'sub-project/**/yarn.lock'
+```