feat(externals): add support for custom node_modules folder, closes #75

Author: nklayman

__tests__/webpackConfig.spec.js

@@ -16,6 +16,8 @@ const mockApi = {
       return '../__tests__/mock_package.json'
     } else if (path.match('./node_modules/mockExternal/package.json')) {
       return 'mockExternalPath'
+    } else if (path.match('customNodeModulesPath/mockExternal/package.json')) {
+      return 'customExternalPath'
     } else if (path.match('./node_modules/mockExternal/index.js')) {
       return 'mockExternalIndex'
     }
@@ -131,7 +133,7 @@ describe.each(['production', 'development'])('getExternals in %s', env => {
     // Mock dep's package.json
     const { readFileSync: realReadFileSync } = fs
     fs.readFileSync = jest.fn((path, ...args) => {
-      if (path === 'mockExternalPath') {
+      if (path === 'mockExternalPath' || path === 'customExternalPath') {
         return JSON.stringify(modulePkg)
       }
       // Don't effect other calls
@@ -187,4 +189,13 @@ describe.each(['production', 'development'])('getExternals in %s', env => {
     )
     expect(externals).toBeUndefined()
   })
+
+  test("Dep's package.json is read from nodeModulesPath", async () => {
+    await mockGetExternals({}, { nodeModulesPath: 'customNodeModulesPath' })
+
+    // App's package.json is read from custom path
+    expect(fs.readFileSync).toBeCalledWith(`customExternalPath`)
+    // Not read from default path
+    expect(fs.readFileSync).not.toBeCalledWith(`mockExternalPath`)
+  })
 })

docs/guide/guide.md

@@ -18,7 +18,9 @@ module.exports = {
   pluginOptions: {
     electronBuilder: {
       // List native deps here if they don't work
-      externals: ['my-native-dep']
+      externals: ['my-native-dep'],
+      // Set this to your project's node_modules folder if it is not ./node_modules (for yarn workspaces)
+      nodeModulesPath: '../../node_modules'
     }
   }
 }

lib/webpackConfig.js

@@ -40,6 +40,7 @@ async function chainWebpack (api, pluginOptions, config) {
 }
 // Find all the dependencies without a `main` property or with a `binary` property or set by user and add them as webpack externals
 function getExternals (api, pluginOptions) {
+  const nodeModulesPath = pluginOptions.nodeModulesPath || './node_modules'
   const userExternals = pluginOptions.externals || []
   const userExternalsWhitelist = []
   userExternals.forEach((d, i) => {
@@ -53,7 +54,7 @@ function getExternals (api, pluginOptions) {
     // Return true if we want to add a dependency to externals
     try {
       const pgkString = fs
-        .readFileSync(api.resolve(`./node_modules/${dep}/package.json`))
+        .readFileSync(api.resolve(`${nodeModulesPath}/${dep}/package.json`))
         .toString()
       const pkg = JSON.parse(pgkString)
       const fields = ['main', 'module', 'jsnext:main', 'browser']