fix: compatibility with Vue 2.7

Author: haoqunjiang

packages/@vue/cli-plugin-typescript/index.js

@@ -82,14 +82,23 @@ module.exports = (api, projectOptions) => {
     // this plugin does not play well with jest + cypress setup (tsPluginE2e.spec.js) somehow
     // so temporarily disabled for vue-cli tests
     if (!process.env.VUE_CLI_TEST) {
+      let vueCompilerPath
+      try {
+        // Vue 2.7+
+        vueCompilerPath = require.resolve('vue/compiler-sfc')
+      } catch (e) {
+        // Vue 2.6 and lower versions
+        vueCompilerPath = require.resolve('vue-template-compiler')
+      }
+
       config
         .plugin('fork-ts-checker')
         .use(require('fork-ts-checker-webpack-plugin'), [{
           typescript: {
             extensions: {
               vue: {
                 enabled: true,
-                compiler: isVue3 ? require.resolve('vue/compiler-sfc') : require.resolve('vue-template-compiler')
+                compiler: vueCompilerPath
               }
             },
             diagnosticOptions: {

packages/@vue/cli-service/lib/config/base.js

@@ -64,9 +64,14 @@ module.exports = (api, options) => {
       const vueLoaderCacheConfig = api.genCacheConfig('vue-loader', {
         'vue-loader': require('@vue/vue-loader-v15/package.json').version,
         '@vue/component-compiler-utils': require('@vue/component-compiler-utils/package.json').version,
-        'vue-template-compiler': require('vue-template-compiler/package.json').version
       })
 
+      try {
+        vueLoaderCacheConfig['vue-template-compiler'] = require('vue-template-compiler/package.json').version
+      } catch (e) {
+        // For Vue 2.7 projects, `vue-template-compiler` is not required
+      }
+
       webpackConfig.resolve
         .alias
           .set(