fix: support usage with other loaders with enforce: post

fix #1351

Author: yyx990803

Diff for: lib/loaders/pitcher.js

@@ -14,14 +14,16 @@ module.exports.pitch = function (remainingRequest) {
   const { cacheDirectory, cacheIdentifier } = options
   const query = qs.parse(this.resourceQuery.slice(1))
 
+  let loaders = this.loaders
+
   // if this is a language block request, remove eslint-loader to avoid
   // duplicate linting.
-  const loaders = query.type
-    ? this.loaders.filter(l => !/(\/|\\|@)eslint-loader/.test(l.path))
-    : this.loaders
+  if (query.type) {
+    loaders = loaders.filter(l => !/(\/|\\|@)eslint-loader/.test(l.path))
+  }
 
   // remove self
-  loaders.shift()
+  loaders = loaders.filter(l => l.path !== __filename)
 
   // do not inject if user uses null-loader to void the type (#1239)
   if (loaders.some(l => /(\/|\\|@)null-loader/.test(l.path))) {

Diff for: test/edgeCases.spec.js

@@ -9,7 +9,11 @@ const {
   mockBundleAndRun
 } = require('./utils')
 
-const assertComponent = ({ window, module }, done) => {
+const assertComponent = ({
+  window,
+  module,
+  expectedMsg = 'Hello from Component A!'
+}, done) => {
   if (typeof module === 'function') {
     module = module.options
   }
@@ -23,7 +27,7 @@ const assertComponent = ({ window, module }, done) => {
   expect(vnode.data.staticClass).toBe('red')
   expect(vnode.children[0].text).toBe('hi')
 
-  expect(module.data().msg).toContain('Hello from Component A!')
+  expect(module.data().msg).toContain(expectedMsg)
   let style = window.document.querySelector('style').textContent
   style = normalizeNewline(style)
   expect(style).toContain('comp-a h2 {\n  color: #f00;\n}')
@@ -184,3 +188,27 @@ test('proper dedupe on src-imports with options', done => {
     }
   }, res => assertComponent(res, done))
 })
+
+// #1351
+test('use with postLoader', done => {
+  mockBundleAndRun({
+    entry: 'basic.vue',
+    module: {
+      rules: [
+        {
+          test: /\.js$/,
+          use: {
+            loader: require.resolve('./mock-loaders/js')
+          },
+          enforce: 'post'
+        }
+      ]
+    }
+  }, ({ window, module }) => {
+    assertComponent({
+      window,
+      module,
+      expectedMsg: 'Changed!'
+    }, done)
+  })
+})