feat(GeneratorAPI): forceOverwrite option for extendPackage

packages/@vue/cli-plugin-webpack-4/generator.js

@@ -44,7 +44,8 @@ module.exports = (api) => {
       return toMerge
     },
     {
-      warnIncompatibleVersions: false
+      warnIncompatibleVersions: false,
+      forceOverwrite: true
     }
   )
 }

packages/@vue/cli/__tests__/Generator.spec.js

@@ -523,6 +523,41 @@ test('api: extendPackage + { warnIncompatibleVersions: false }', async () => {
   })
 })
 
+test('api: extendPackage + { forceOverwrite: true }', async () => {
+  const generator = new Generator('/', {
+    pkg: {
+      devDependencies: {
+        'sass-loader': '^11.0.0'
+      }
+    },
+    plugins: [{
+      id: 'test',
+      apply: api => {
+        api.extendPackage(
+          {
+            devDependencies: {
+              'sass-loader': '^10.0.0'
+            }
+          },
+          { warnIncompatibleVersions: false, forceOverwrite: true }
+        )
+      }
+    }]
+  })
+
+  await generator.generate()
+  const pkg = JSON.parse(fs.readFileSync('/package.json', 'utf-8'))
+
+  // should not warn about the version conflicts
+  expect(logs.warn.length).toBe(0)
+  // should use the newer version
+  expect(pkg).toEqual({
+    devDependencies: {
+      'sass-loader': '^10.0.0'
+    }
+  })
+})
+
 test('api: render fs directory', async () => {
   const generator = new Generator('/', {
     plugins: [

packages/@vue/cli/lib/GeneratorAPI.js

@@ -219,12 +219,15 @@ class GeneratorAPI {
    *    that dependency fields are always deep merged regardless of this option.
    * @param {boolean} [options.warnIncompatibleVersions=true] Output warning
    *    if two dependency version ranges don't intersect.
+   * @param {boolean} [options.forceOverwrite=false] force using the dependency
+   * version provided in the first argument, instead of trying to get the newer ones
    */
   extendPackage (fields, options = {}) {
     const extendOptions = {
       prune: false,
       merge: true,
-      warnIncompatibleVersions: true
+      warnIncompatibleVersions: true,
+      forceOverwrite: false
     }
 
     // this condition statement is added for compatibility reason, because

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

@@ -28,7 +28,8 @@ module.exports = function mergeDeps (
   sources,
   {
     prune,
-    warnIncompatibleVersions
+    warnIncompatibleVersions,
+    forceOverwrite
   }
 ) {
   const result = Object.assign({}, sourceDeps)
@@ -63,11 +64,15 @@ module.exports = function mergeDeps (
       const r = tryGetNewerRange(sourceRangeSemver, injectingRangeSemver)
       const didGetNewer = !!r
 
-      // if failed to infer newer version, use existing one because it's likely
-      // built-in
-      result[depName] = didGetNewer
-        ? injectSemver(injectingRange, r)
-        : sourceRange
+      if (forceOverwrite) {
+        result[depName] = injectingRange
+      } else if (didGetNewer) {
+        result[depName] = injectSemver(injectingRange, r)
+      } else {
+        // if failed to infer newer version, use existing one because it's likely
+        // built-in
+        result[depName] = sourceRange
+      }
 
       // if changed, update source
       if (result[depName] === injectingRange) {
@@ -85,7 +90,7 @@ module.exports = function mergeDeps (
           `conflicting versions for project dependency "${depName}":\n\n` +
             `- ${sourceRange} injected by generator "${sourceGeneratorId}"\n` +
             `- ${injectingRange} injected by generator "${generatorId}"\n\n` +
-            `Using ${didGetNewer ? `newer ` : ``}version (${
+            `Using ${(!forceOverwrite && didGetNewer) ? `newer ` : ``}version (${
               result[depName]
             }), but this may cause build errors.`
         )

packages/@vue/cli/types/cli-test.ts

@@ -112,7 +112,8 @@ const generator: GeneratorPlugin = (api, options, rootOptions, invoking) => {
     {
       merge: true,
       prune: true,
-      warnIncompatibleVersions: true
+      warnIncompatibleVersions: true,
+      forceOverwrite: true
     }
   )
 

packages/@vue/cli/types/index.d.ts

@@ -38,6 +38,7 @@ type ExtendPackageOptions =
       prune?: boolean
       merge?: boolean
       warnIncompatibleVersions?: boolean
+      forceOverwrite?: boolean
     }
   | boolean
 
@@ -121,6 +122,8 @@ declare class GeneratorAPI {
    *    that dependency fields are always deep merged regardless of this option.
    * @param [options.warnIncompatibleVersions=true] Output warning
    *    if two dependency version ranges don't intersect.
+   * @param [options.forceOverwrite=false] force using the dependency
+   * version provided in the first argument, instead of trying to get the newer ones
    */
   extendPackage(
     fields: (pkg: Record<string, any>) => object,