Copy node_modules folder when symlink fails

src/deploy-builder.ts

@@ -0,0 +1,42 @@
+import * as path from 'path'
+import * as fs from 'fs-p'
+
+export class DeployBuilder {
+  build(buildFolder: string) {
+    const buildPath = path.resolve(buildFolder)
+
+    if (this.isNodeModulesAbsent(buildPath)) {
+      this.createNodeModulesFolder(buildPath)
+    }
+  }
+
+  private isNodeModulesAbsent(buildPath: string): boolean {
+    return !fs.existsSync(path.join(buildPath, 'node_modules'))
+  }
+
+  private createNodeModulesFolder(buildPath: string) {
+    try {
+      fs.symlinkSync(path.resolve('node_modules'), path.join(buildPath, 'node_modules'))
+    } catch (error) {
+      this.copyIfMissingSymlinkPermission(buildPath, error)
+    }
+  }
+
+  private copyIfMissingSymlinkPermission(buildPath: string, error: SymlinkException) {
+    if (this.isMissingSymlinkPermission(error)) {
+      fs.copySync(path.resolve('node_modules'), path.join(buildPath, 'node_modules'))
+    } else {
+      throw error
+    }
+  }
+
+  private isMissingSymlinkPermission(error: SymlinkException): boolean {
+    // Generally happens when no admin rights with UAC enabled on Windows.
+    return error.code === 'EPERM' && error.errno === -4048
+  }
+}
+
+export interface SymlinkException {
+  code: string
+  errno: number
+}

src/index.ts

@@ -3,6 +3,7 @@ import * as fs from 'fs-p'
 import * as _ from 'lodash'
 import * as globby from 'globby'
 
+import { DeployBuilder } from './deploy-builder'
 import { ServerlessOptions, ServerlessInstance, ServerlessFunction } from './types'
 import * as typescript from './typescript'
 
@@ -11,7 +12,6 @@ const serverlessFolder = '.serverless'
 const buildFolder = '.build'
 
 class ServerlessPlugin {
-
   private originalServicePath: string
   private originalFunctions: { [key: string]: ServerlessFunction } | {}
 
@@ -20,6 +20,8 @@ class ServerlessPlugin {
   commands: { [key: string]: any }
   hooks: { [key: string]: Function }
 
+  private deployBuilder: DeployBuilder
+
   constructor(serverless: ServerlessInstance, options: ServerlessOptions) {
     this.serverless = serverless
     this.options = options
@@ -56,6 +58,8 @@ class ServerlessPlugin {
         },
       },
     }
+
+    this.deployBuilder = new DeployBuilder()
   }
 
   async beforeCreateDeploymentArtifacts(type: string): Promise<void> {
@@ -86,10 +90,7 @@ class ServerlessPlugin {
 
     await typescript.run(tsFileNames, tsconfig)
 
-    // include node_modules into build
-    if (!fs.existsSync(path.resolve(path.join(buildFolder, 'node_modules')))) {
-      fs.symlinkSync(path.resolve('node_modules'), path.resolve(path.join(buildFolder, 'node_modules')))
-    }
+    this.deployBuilder.build(buildFolder)
 
     // include any "extras" from the "include" section
     if (this.serverless.service.package.include && this.serverless.service.package.include.length > 0) {