feat(build/serve): Support multiple node_module paths, closes #75

Author: nklayman

__tests__/webpackConfig.spec.js

@@ -21,6 +21,7 @@ const mockApi = {
     } else if (path.match('./node_modules/mockExternal/index.js')) {
       return 'mockExternalIndex'
     }
+    return path
   })
 }
 
@@ -115,6 +116,10 @@ describe('chainWebpack', () => {
 describe.each(['production', 'development'])('getExternals in %s', env => {
   process.env.NODE_ENV = env
 
+  fs.existsSync.mockImplementation(
+    path => path === 'mockExternalPath' || path === 'customExternalPath'
+  )
+
   const mockGetExternals = async (
     modulePkg = {},
     pluginOptions,
@@ -198,4 +203,16 @@ describe.each(['production', 'development'])('getExternals in %s', env => {
     // Not read from default path
     expect(fs.readFileSync).not.toBeCalledWith(`mockExternalPath`)
   })
+
+  test('Checks multiple locations for dep package.json', async () => {
+    await mockGetExternals(
+      {},
+      { nodeModulesPath: ['wrongPath', 'customNodeModulesPath'] }
+    )
+    // Checked both paths
+    expect(fs.existsSync).toBeCalledWith('wrongPath/mockExternal/package.json')
+    expect(fs.existsSync).toBeCalledWith('customExternalPath')
+    // Read from proper path
+    expect(fs.readFileSync).toBeCalledWith('customExternalPath')
+  })
 })

lib/webpackConfig.js

@@ -41,6 +41,14 @@ 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'
+  let nodeModulesPaths = []
+  if (Array.isArray(nodeModulesPath)) {
+    // Set to user-defined array
+    nodeModulesPaths = nodeModulesPath
+  } else {
+    // Add path to list
+    nodeModulesPaths.push(nodeModulesPath)
+  }
   const userExternals = pluginOptions.externals || []
   const userExternalsWhitelist = []
   userExternals.forEach((d, i) => {
@@ -53,9 +61,20 @@ function getExternals (api, pluginOptions) {
   const externalsList = Object.keys(dependencies || {}).filter(dep => {
     // Return true if we want to add a dependency to externals
     try {
-      const pgkString = fs
-        .readFileSync(api.resolve(`${nodeModulesPath}/${dep}/package.json`))
-        .toString()
+      let pgkString
+      for (const path of nodeModulesPaths) {
+        // Check if package.json exists
+        if (fs.existsSync(api.resolve(`${path}/${dep}/package.json`))) {
+          // If it does, read it and break
+          pgkString = fs
+            .readFileSync(api.resolve(`${path}/${dep}/package.json`))
+            .toString()
+          break
+        }
+      }
+      if (!pgkString) {
+        throw new Error(`Could not find a package.json for module ${dep}`)
+      }
       const pkg = JSON.parse(pgkString)
       const fields = ['main', 'module', 'jsnext:main', 'browser']
       return (