test: use offline install for test projects (for vue upgrade)

Author: haoqunjiang

.circleci/config.yml

@@ -52,7 +52,16 @@ jobs:
           at: ~/
       - run: yarn lint-without-fix
       - run: yarn check-links
+      - restore_cache:
+        keys:
+          # TODO: should use a more accurate cache key
+          - v2-vue-cli-offline-{{ .Branch }}-{{ checksum "yarn.lock" }}
+      - run: yarn config set yarn-offline-mirror ~/npm-packages-offline-cache
       - run: yarn test -p cli-service-global,eslint,pwa,babel,babel-preset-app,vuex,router
+      - save_cache:
+        key: v2-vue-cli-offline-{{ .Branch }}-{{ checksum "yarn.lock" }}
+        paths:
+          - ~/npm-packages-offline-cache
 
   group-4:
     <<: *defaults

appveyor.yml

@@ -10,13 +10,15 @@ test_script:
   - git --version
   - node --version
   - yarn --version
+  - yarn config set yarn-offline-mirror ./npm-packages-offline-cache
   - yarn test
   # ui tests temporarily disabled due to Cypress 3.0 issue on windows
   # - cd "packages/@vue/cli-ui" && yarn test
 
 cache:
   - node_modules -> appveyor.yml, **\package.json, yarn.lock
   - '%LOCALAPPDATA%\Yarn -> appveyor.yml, **\package.json, yarn.lock'
+  - npm-packages-offline-cache -> appveyor.yml, **\package.json, yarn.lock
 
 build: off
 

packages/@vue/cli/lib/util/ProjectPackageManager.js

@@ -241,6 +241,14 @@ class PackageManager {
   }
 
   async install () {
+    if (process.env.VUE_CLI_TEST) {
+      try {
+        return this.runCommand([PACKAGE_MANAGER_CONFIG[this.bin].install, '--offline'])
+      } catch (e) {
+        this.runCommand([PACKAGE_MANAGER_CONFIG[this.bin].install])
+      }
+    }
+
     return this.runCommand([PACKAGE_MANAGER_CONFIG[this.bin].install])
   }