Run lint and unit tests on Buildkite (#17)

.buildkite/commands/install-node-dependencies.sh

@@ -0,0 +1,49 @@
+#!/bin/bash -eu
+
+PLATFORM=$(uname -s)
+ARCHITECTURE=$(uname -m)
+NODE_VERSION=$(node --version)
+PACKAGE_HASH=$(hash_file package-lock.json)
+
+CACHEKEY="$BUILDKITE_PIPELINE_SLUG-npm-$PLATFORM-$ARCHITECTURE-node-$NODE_VERSION-$PACKAGE_HASH"
+
+LOCAL_NPM_CACHE=./vendor/npm
+mkdir -p $LOCAL_NPM_CACHE
+echo "--- :npm: Set npm to use $LOCAL_NPM_CACHE for cache"
+npm set cache $LOCAL_NPM_CACHE
+echo "npm cache set to $(npm get cache)"
+
+echo "--- :npm: Restore npm cache if present"
+restore_cache "$CACHEKEY"
+
+echo "--- :npm: Install Node dependencies"
+
+MAX_SOCKETS=15 # Default value from npm
+
+# To avoid constant ECONNRESET errors a limit is set for Linux,
+# as this is not happening with the Mac jobs.
+# This issue is being tracked here:
+# https://github.com/npm/cli/issues/4652
+if [ "$PLATFORM" = "Linux" ]; then
+  MAX_SOCKETS=1
+fi
+
+npm ci \
+  --unsafe-perm \
+  --prefer-offline \
+  --no-audit \
+  --no-progress \
+  --maxsockets "$MAX_SOCKETS" \
+  "$@"
+
+echo "--- :npm: Save cache if necessary"
+# Notice that we don't cache the local node_modules.
+# Those get regenerated by npm ci as per Node reccomendations.
+# What we are caching is the root npm folder, which stores pacakge downloads so they are available if the package.json resolution demands them.
+#
+# npm stores temporary files in ~/.npm that we don't want to extract because they might run into naming conflicts.
+# So, before archiving it, we remove those tmp files.
+#
+# Example: https://buildkite.com/automattic/gutenberg-mobile/builds/8857#018e37eb-7afc-4280-b736-cba76f02f1a3/524
+rm -rf "$LOCAL_NPM_CACHE/_cacache/tmp"
+save_cache "$LOCAL_NPM_CACHE" "$CACHEKEY"

.buildkite/pipeline.yml

@@ -1,16 +1,36 @@
 # Nodes with values to reuse in the pipeline.
 common_params:
   plugins: &common_plugins
-    - automattic/a8c-ci-toolkit#3.1.0
+    - automattic/a8c-ci-toolkit#3.3.0
     - automattic/nvm#0.3.0
 
-# All current steps use the same agent and environment; we can define them as top-level
+# Most of steps use the same agent and environment; we can define them as top-level
 agents:
   queue: mac
 env:
   IMAGE_ID: xcode-15.2
 
 steps:
+  - label: Lint
+    key: lint
+    command: |
+      .buildkite/commands/install-node-dependencies.sh
+      echo '--- :eslint: Lint'
+      npm run lint
+    agents:
+      queue: default
+    plugins: *common_plugins
+
+  - label: Unit Tests
+    key: unit_tests
+    command: |
+      .buildkite/commands/install-node-dependencies.sh
+      echo '--- :npm: Run Unit Tests'
+      npm run test
+    agents:
+      queue: default
+    plugins: *common_plugins
+
   - group: "📦 Build for Mac"
     key: 'dev-mac'
     steps:
@@ -19,7 +39,7 @@ steps:
           .buildkite/commands/prepare-environment.sh
 
           echo "--- :node: Building Binary"
-          install_npm_packages
+          .buildkite/commands/install-node-dependencies.sh
           node ./scripts/prepare-dev-build-version.mjs
           npm run make:macos-{{matrix}}
 
@@ -68,9 +88,9 @@ steps:
     key: 'release-mac'
     command: |
       .buildkite/commands/prepare-environment.sh
+      .buildkite/commands/install-node-dependencies.sh
 
       echo "--- :node: Building Binary"
-      npm install
       node ./scripts/confirm-tag-matches-version.mjs
       npm run make:macos-x64
       npm run make:macos-arm64