Only allow single slash at start of scriptUrl (#57)

* Only allow single slash at start of scriptUrl.

Fixes default public path colliding with absolute filename.

* Use path.join() instead of string concat + regex replace.

* Add testcase for stripping extra slashes

.eslintignore

@@ -2,3 +2,4 @@ node_modules
 /lib
 /docs/dist
 /flow/interfaces
+/tmp-build

.gitignore

@@ -2,3 +2,5 @@
 /node_modules
 /lib
 /docs/dist
+.idea/
+tmp-build/

docs/src/sw.js

@@ -116,7 +116,9 @@ self.addEventListener('fetch', event => {
         if (!responseNetwork || !responseNetwork.ok) {
           if (DEBUG) {
             console.log(
-              `[SW] URL [${requestUrl.toString()}] wrong responseNetwork: ${responseNetwork.status} ${responseNetwork.type}`
+              `[SW] URL [${requestUrl.toString()}] wrong responseNetwork: ${
+                responseNetwork.status
+              } ${responseNetwork.type}`
             )
           }
 

package.json

@@ -75,6 +75,7 @@
     "react": "^15.6.1",
     "react-dom": "^15.6.1",
     "react-hot-loader": "^3.0.0-beta.6",
+    "rimraf": "^2.6.2",
     "sass-loader": "^6.0.6",
     "style-loader": "^0.18.2",
     "webpack": "^3.5.5",

src/index.js

@@ -61,7 +61,7 @@ export default class ServiceWorkerPlugin {
         // Hijack the original module
         if (result.resource === runtimePath) {
           const data = {
-            scriptURL: this.options.publicPath + this.options.filename,
+            scriptURL: path.join(this.options.publicPath, this.options.filename),
           }
 
           result.loaders.push(`${path.join(__dirname, 'runtimeLoader.js')}?${JSON.stringify(data)}`)

src/index.spec.js

@@ -1,16 +1,41 @@
 // @flow weak
 /* eslint-env mocha */
 
-import { assert } from 'chai'
+import webpack from 'webpack'
+import path from 'path'
+import fs from 'fs'
+import rimraf from 'rimraf'
+import { assert, expect } from 'chai'
 import ServiceWorkerPlugin from './index'
 
 function trim(str) {
   return str.replace(/^\s+|\s+$/, '')
 }
 
 const filename = 'sw.js'
+const webpackOutputPath = path.resolve('./tmp-build')
+const makeWebpackConfig = options => ({
+  entry: path.join(__dirname, '../test/test-build-entry'),
+  plugins: [
+    new ServiceWorkerPlugin({
+      entry: path.join(__dirname, '../test/test-build-sw'),
+      ...options,
+    }),
+  ],
+  resolve: {
+    alias: {
+      'serviceworker-webpack-plugin/lib/runtime': path.join(__dirname, 'runtime.js'),
+    },
+  },
+  output: {
+    path: webpackOutputPath,
+  },
+})
 
 describe('ServiceWorkerPlugin', () => {
+  beforeEach(done => {
+    return rimraf(webpackOutputPath, done)
+  })
   describe('options: filename', () => {
     it('should throw if trying to hash the filename', () => {
       assert.throws(() => {
@@ -20,6 +45,24 @@ describe('ServiceWorkerPlugin', () => {
         })
       }, /The name of the/)
     })
+    it('should strip double slashes', done => {
+      const options = makeWebpackConfig({
+        filename: '//sw.js',
+      })
+      return webpack(options, (err, stats) => {
+        expect(err).to.equal(null)
+        const { assetsByChunkName, errors, warnings } = stats.toJson()
+        expect(errors).to.have.length(0)
+        expect(warnings).to.have.length(0)
+
+        const mainFile = fs.readFileSync(
+          path.join(webpackOutputPath, assetsByChunkName.main),
+          'utf8'
+        )
+        expect(mainFile).to.include('var serviceWorkerOption = {"scriptURL":"/sw.js"}')
+        done()
+      })
+    })
   })
 
   describe('options: includes', () => {

test/test-build-entry.js

@@ -0,0 +1,3 @@
+import runtime from 'serviceworker-webpack-plugin/lib/runtime'
+
+runtime.register({ scope: '/' })

test/test-build-sw.js

@@ -0,0 +1 @@
+// intentionally left empty