fix(vue-app): prevent looping on error during render of error page (#6217)

packages/vue-app/template/components/nuxt.js

@@ -34,6 +34,15 @@ export default {
       default: 'default'
     }
   },
+  errorCaptured (error) {
+    // if we receive and error while showing the NuxtError component
+    // capture the error and force an immediate update so we re-render
+    // without the NuxtError component
+    if (this.displayingNuxtError) {
+      this.errorFromNuxtError = error
+      this.$forceUpdate()
+    }
+  },
   computed: {
     routerViewKey() {
       // If nuxtChildKey prop is given or current route has children
@@ -65,18 +74,36 @@ export default {
     Vue.util.defineReactive(this, 'nuxt', this.$root.$options.nuxt)
   },
   render(h) {
-    // If there is some error
-    if (this.nuxt.err) {
-      return h('NuxtError', {
-        props: {
-          error: this.nuxt.err
-        }
-      })
-    }
+    // if there is no error
+    if (!this.nuxt.err) {
       // Directly return nuxt child
       return h('NuxtChild', {
         key: this.routerViewKey,
         props: this.$props
       })
     }
+
+    // if an error occured within NuxtError show a simple
+    // error message instead to prevent looping
+    if (this.errorFromNuxtError) {
+      this.$nextTick(() => (this.errorFromNuxtError = false))
+
+      return h('div', {}, [
+        h('h2', 'An error occured while showing the error page'),
+        h('p', 'Unfortunately an error occured and while showing the error page another error occured'),
+        h('p', `Error details: ${this.errorFromNuxtError.toString()}`),
+        h('nuxt-link', { props: { to: '/' } }, 'Go back to home')
+      ])
+    }
+
+    // track if we are showing the NuxtError component
+    this.displayingNuxtError = true
+    this.$nextTick(() => (this.displayingNuxtError = false))
+
+    return h(NuxtError, {
+      props: {
+        error: this.nuxt.err
+      }
+    })
+  }
 }

test/e2e/error.test.js

@@ -0,0 +1,60 @@
+import Browser from '../utils/browser'
+import { loadFixture, getPort, Nuxt } from '../utils'
+
+let port
+const browser = new Browser()
+const url = route => 'http://localhost:' + port + route
+
+let nuxt = null
+let page = null
+
+describe('basic browser', () => {
+  beforeAll(async () => {
+    const config = await loadFixture('error')
+    nuxt = new Nuxt(config)
+    await nuxt.ready()
+
+    port = await getPort()
+    await nuxt.server.listen(port, 'localhost')
+
+    await browser.start({
+      // slowMo: 50,
+      // headless: false
+    })
+  })
+
+  test('Open /', async () => {
+    page = await browser.page(url('/'))
+
+    expect(await page.$text('h1')).toBe('Error Loop incoming page')
+  })
+
+  test('/squared doesnt loop due to error on error page', async () => {
+    await page.nuxt.navigate('/squared')
+
+    expect(await page.$text('h2')).toBe('An error occured while showing the error page')
+  })
+
+  test('/about loads normally', async () => {
+    await page.nuxt.navigate('/about')
+
+    expect(await page.$text('h1')).toBe('About')
+  })
+
+  test('/info prints empty page', async () => {
+    await page.nuxt.navigate('/info')
+
+    expect(await page.$text('#__layout')).toBe('')
+  })
+
+  // Close server and ask nuxt to stop listening to file changes
+  afterAll(async () => {
+    await nuxt.close()
+  })
+
+  // Stop browser
+  afterAll(async () => {
+    await page.close()
+    await browser.close()
+  })
+})

test/fixtures/error/layouts/error.vue

@@ -0,0 +1,17 @@
+<template>
+  <div>
+    <h1>Error</h1>
+    <p>Details: {{ this.$route.path === '/squared' ? error.response.data : error.message }}</p>
+
+    <nuxt-link to="/">
+      back
+    </nuxt-link>
+  </div>
+</template>
+
+<script>
+export default {
+  // eslint-disable-next-line vue/require-prop-types
+  props: ['error']
+}
+</script>

test/fixtures/error/nuxt.config.js

@@ -1,2 +0,0 @@
-export default {
-}

test/fixtures/error/pages/about.vue

@@ -0,0 +1,8 @@
+<template>
+  <div>
+    <h1>About</h1>
+    <nuxt-link to="/">
+      back
+    </nuxt-link>
+  </div>
+</template>

test/fixtures/error/pages/error.vue

@@ -0,0 +1,10 @@
+<template>
+  <h1>Error page</h1>
+</template>
+
+<script>
+/* eslint no-undef: 0 */
+export default {
+  not_defined
+}
+</script>

test/fixtures/error/pages/index.vue

@@ -1,10 +1,14 @@
 <template>
-  <h1>Error page</h1>
+  <div>
+    <h1>Error Loop incoming page</h1>
+    <nuxt-link id="squared" to="/squared">
+      Error during error
+    </nuxt-link>
+    <nuxt-link id="about" to="/about">
+      About
+    </nuxt-link>
+    <nuxt-link id="info" to="/info">
+      Info (with error)
+    </nuxt-link>
+  </div>
 </template>
-
-<script>
-/* eslint no-undef: 0 */
-export default {
-  not_defined
-}
-</script>

test/fixtures/error/pages/info.vue

@@ -0,0 +1,19 @@
+<template>
+  <div>
+    <h1>Info</h1>
+    <p>Details: {{ info.message.title }}</p>
+    <nuxt-link to="/">
+      back
+    </nuxt-link>
+  </div>
+</template>
+
+<script>
+export default {
+  data () {
+    return {
+      info: {}
+    }
+  }
+}
+</script>

test/unit/error.test.js

@@ -19,7 +19,7 @@ describe('error', () => {
   })
 
   test('/ should display an error', async () => {
-    await expect(nuxt.server.renderRoute('/')).rejects.toMatchObject({
+    await expect(nuxt.server.renderRoute('/error')).rejects.toMatchObject({
       message: expect.stringContaining('not_defined is not defined')
     })
   })
@@ -30,14 +30,14 @@ describe('error', () => {
   })
 
   test('/ with renderAndGetWindow()', async () => {
-    await expect(nuxt.server.renderAndGetWindow(url('/'))).rejects.toMatchObject({
+    await expect(nuxt.server.renderAndGetWindow(url('/error'))).rejects.toMatchObject({
       statusCode: 500
     })
   })
 
   test('Error: resolvePath()', () => {
     expect(() => nuxt.resolver.resolvePath()).toThrowError()
-    expect(() => nuxt.resolver.resolvePath('@/pages/about.vue')).toThrowError('Cannot resolve "@/pages/about.vue"')
+    expect(() => nuxt.resolver.resolvePath('@/pages/not-found.vue')).toThrowError('Cannot resolve "@/pages/not-found.vue"')
   })
 
   test('Error: callHook()', async () => {
@@ -56,6 +56,24 @@ describe('error', () => {
     expect(consola.fatal).toHaveBeenCalledWith(error)
   })
 
+  test('/info should display an error', async () => {
+    await expect(nuxt.server.renderRoute('/info')).rejects.toMatchObject({
+      message: expect.stringContaining(`Cannot read property 'title' of undefined`)
+    })
+  })
+
+  test('/about should work', async () => {
+    await expect(nuxt.server.renderRoute('/about')).resolves.toMatchObject({
+      html: expect.stringContaining('About')
+    })
+  })
+
+  test('/error-square should display an error', async () => {
+    await expect(nuxt.server.renderRoute('/squared')).rejects.toMatchObject({
+      message: expect.stringContaining(`Cannot read property 'data' of undefined`)
+    })
+  })
+
   // Close server and ask nuxt to stop listening to file changes
   afterAll(async () => {
     await nuxt.close()