feat: support inline CSS (#190)

Will Howlett · gregberge · commit 2caf6765959d · 2019-01-11T14:03:40.000+01:00
diff --git a/packages/server/README.md b/packages/server/README.md
@@ -276,6 +276,17 @@ Get style links as a string of `<link>` tags.
 const head = `<head>${chunkExtractor.getStyleTags()}</head>`
 ```
 
+### chunkExtractor.getInlineStyleTags
+
+Get inline style links as a string of `<link>` tags (returns a promise).
+
+```js
+chunkExtractor.getInlineStyleTags()
+.then((styleTags) => {
+  const head = `<head>${styleTags}</head>`
+}
+```
+
 ### chunkExtractor.getStyleElements
 
 Get style links as an array of React `<link>` elements.
@@ -284,6 +295,34 @@ Get style links as an array of React `<link>` elements.
 const head = renderToString(<head>{chunkExtractor.getStyleElements()}</head>)
 ```
 
+### chunkExtractor.getInlineStyleElements
+
+Get inline style links as an array of React `<link>` elements (returns a promise).
+
+```js
+chunkExtractor.getInlineStyleElements()
+.then((styleElements) => {
+  const head = renderToString(<head>{styleElements}</head>)
+}
+```
+
+### chunkExtractor.getCssString
+
+Get css as a raw string for using directly within app (e.g. in custom AMP style tag)
+
+```js
+chunkExtractor.getCssString()
+.then((cssString) => {
+  const head = renderToString(
+    <head>
+      <style
+        dangerouslySetInnerHTML={{ __html: cssString }}
+      />
+    </head>
+  )
+}
+```
+
 ### ChunkExtractorManager
 
 Used to inject a `ChunkExtractor` in the context of your application.
diff --git a/packages/server/__fixtures__/letters-A.css b/packages/server/__fixtures__/letters-A.css
@@ -0,0 +1,3 @@
+body {
+  background: pink;
+}
diff --git a/packages/server/__fixtures__/main.css b/packages/server/__fixtures__/main.css
@@ -0,0 +1,3 @@
+h1 {
+  color: cyan;
+}
diff --git a/packages/server/src/ChunkExtractor.js b/packages/server/src/ChunkExtractor.js
@@ -1,5 +1,6 @@
 /* eslint-disable react/no-danger */
 import path from 'path'
+import fs from 'fs'
 import _ from 'lodash'
 import React from 'react'
 import { invariant, LOADABLE_REQUIRED_CHUNKS_KEY } from './sharedInternals'
@@ -31,12 +32,41 @@ function assetToScriptElement(asset) {
   )
 }
 
+function assetToStyleString(asset) {
+  return new Promise((resolve, reject) => {
+    fs.readFile(asset.path, 'utf8', (err, data) => {
+      if (err) {
+        reject(err);
+        return;
+      }
+      resolve(data);
+    })
+  })
+}
+
 function assetToStyleTag(asset) {
   return `<link data-chunk="${asset.chunk}" rel="stylesheet" href="${
     asset.url
   }">`
 }
 
+function assetToStyleTagInline(asset) {
+  return new Promise((resolve, reject) => {
+    fs.readFile(asset.path, 'utf8', (err, data) => {
+      if (err) {
+        reject(err);
+        return;
+      }
+      resolve(
+        `<style data-chunk="${asset.chunk}">
+        ${data}
+        </style>
+        `
+      );
+    })
+  })
+}
+
 function assetToStyleElement(asset) {
   return (
     <link
@@ -48,6 +78,24 @@ function assetToStyleElement(asset) {
   )
 }
 
+function assetToStyleElementInline(asset) {
+  return new Promise((resolve, reject) => {
+    fs.readFile(asset.path, 'utf8', (err, data) => {
+      if (err) {
+        reject(err);
+        return;
+      }
+      resolve(
+        <style
+          key={asset.url}
+          data-chunk={asset.chunk}
+          dangerouslySetInnerHTML={{ __html: data }}
+        />
+      );
+    })
+  })
+}
+
 const LINK_ASSET_HINTS = {
   mainAsset: 'data-chunk',
   childAsset: 'data-parent-chunk',
@@ -244,15 +292,33 @@ class ChunkExtractor {
     return [requiredScriptElement, ...assetsScriptElements]
   }
 
+  getCssString() {
+    const mainAssets = this.getMainAssets('style')
+    const promises = mainAssets.map((asset) => assetToStyleString(asset).then(data => data))
+    return Promise.all(promises).then(results => joinTags(results))
+  }
+
   getStyleTags() {
     const mainAssets = this.getMainAssets('style')
     return joinTags(mainAssets.map(asset => assetToStyleTag(asset)))
   }
 
+  getInlineStyleTags() {
+    const mainAssets = this.getMainAssets('style')
+    const promises = mainAssets.map((asset) => assetToStyleTagInline(asset).then(data => data))
+    return Promise.all(promises).then(results => joinTags(results))
+  }
+  
   getStyleElements() {
     const mainAssets = this.getMainAssets('style')
     return mainAssets.map(asset => assetToStyleElement(asset))
   }
+  
+  getInlineStyleElements() {
+    const mainAssets = this.getMainAssets('style')
+    const promises = mainAssets.map((asset) => assetToStyleElementInline(asset).then(data => data))
+    return Promise.all(promises).then(results => results)
+  }
 
   // Pre assets
 
diff --git a/packages/server/src/ChunkExtractor.test.js b/packages/server/src/ChunkExtractor.test.js
@@ -3,30 +3,36 @@ import stats from '../__fixtures__/stats.json'
 import ChunkExtractor from './ChunkExtractor'
 
 describe('ChunkExtrator', () => {
+  let extractor
+
+  beforeEach(() => {
+    extractor = new ChunkExtractor({
+      stats,
+      outputPath: path.resolve(__dirname, '../__fixtures__'),
+    })
+  })
+
   describe('#stats', () => {
     it('should load stats from file', () => {
-      const extractor = new ChunkExtractor({
+      extractor = new ChunkExtractor({
         statsFile: path.resolve(__dirname, '../__fixtures__/stats.json'),
       })
 
       expect(extractor.stats).toBe(stats)
     })
 
     it('should load stats from stats', () => {
-      const extractor = new ChunkExtractor({ stats })
       expect(extractor.stats).toBe(stats)
     })
   })
 
   describe('#addChunk', () => {
     it('should reference chunk', () => {
-      const extractor = new ChunkExtractor({ stats })
       extractor.addChunk('foo')
       expect(extractor.chunks).toEqual(['foo'])
     })
 
     it('should be uniq', () => {
-      const extractor = new ChunkExtractor({ stats })
       extractor.addChunk('a')
       extractor.addChunk('b')
       extractor.addChunk('b')
@@ -36,15 +42,13 @@ describe('ChunkExtrator', () => {
 
   describe('#getScriptTags', () => {
     it('should return main script tag without chunk', () => {
-      const extractor = new ChunkExtractor({ stats })
       expect(extractor.getScriptTags()).toMatchInlineSnapshot(`
 "<script>window.__LOADABLE_REQUIRED_CHUNKS__ = [];</script>
 <script async data-chunk=\\"main\\" src=\\"/dist/node/main.js\\"></script>"
 `)
     })
 
     it('should return other chunks if referenced', () => {
-      const extractor = new ChunkExtractor({ stats })
       extractor.addChunk('letters-A')
       expect(extractor.getScriptTags()).toMatchInlineSnapshot(`
 "<script>window.__LOADABLE_REQUIRED_CHUNKS__ = [\\"letters-A\\"];</script>
@@ -56,7 +60,6 @@ describe('ChunkExtrator', () => {
 
   describe('#getScriptElements', () => {
     it('should return main script tag without chunk', () => {
-      const extractor = new ChunkExtractor({ stats })
       expect(extractor.getScriptElements()).toMatchInlineSnapshot(`
 Array [
   <script
@@ -76,7 +79,6 @@ Array [
     })
 
     it('should return other chunks if referenced', () => {
-      const extractor = new ChunkExtractor({ stats })
       extractor.addChunk('letters-A')
       expect(extractor.getScriptElements()).toMatchInlineSnapshot(`
 Array [
@@ -104,25 +106,47 @@ Array [
 
   describe('#getStyleTags', () => {
     it('should return main style tag without chunk', () => {
-      const extractor = new ChunkExtractor({ stats })
       expect(extractor.getStyleTags()).toMatchInlineSnapshot(
         `"<link data-chunk=\\"main\\" rel=\\"stylesheet\\" href=\\"/dist/node/main.css\\">"`,
       )
     })
 
     it('should return other chunks if referenced', () => {
-      const extractor = new ChunkExtractor({ stats })
       extractor.addChunk('letters-A')
       expect(extractor.getStyleTags()).toMatchInlineSnapshot(`
 "<link data-chunk=\\"letters-A\\" rel=\\"stylesheet\\" href=\\"/dist/node/letters-A.css\\">
 <link data-chunk=\\"main\\" rel=\\"stylesheet\\" href=\\"/dist/node/main.css\\">"
 `)
     })
+
+  })
+
+  describe('#getInlineStyleTags', () => {
+    it('should return inline style tags as a promise', () => {
+      extractor.addChunk('letters-A')
+      expect.assertions(1)
+      return extractor.getInlineStyleTags().then(data => expect(data).toMatchInlineSnapshot(`
+"<style data-chunk=\\"letters-A\\">
+        body {
+  background: pink;
+}
+
+        </style>
+        
+<style data-chunk=\\"main\\">
+        h1 {
+  color: cyan;
+}
+        </style>
+        "
+`),
+      )
+    })
+
   })
 
   describe('#getStyleElements', () => {
     it('should return main style tag without chunk', () => {
-      const extractor = new ChunkExtractor({ stats })
       expect(extractor.getStyleElements()).toMatchInlineSnapshot(`
 Array [
   <link
@@ -135,7 +159,6 @@ Array [
     })
 
     it('should return other chunks if referenced', () => {
-      const extractor = new ChunkExtractor({ stats })
       extractor.addChunk('letters-A')
       expect(extractor.getStyleElements()).toMatchInlineSnapshot(`
 Array [
@@ -152,11 +175,63 @@ Array [
 ]
 `)
     })
+
+  })
+
+  describe('#getInlineStyleElements', () => {
+    it('should return inline style elements as a promise', () => {
+      extractor.addChunk('letters-A')
+      expect.assertions(1)
+      return extractor.getInlineStyleElements().then(data => expect(data).toMatchInlineSnapshot(`
+Array [
+  <style
+    dangerouslySetInnerHTML={
+      Object {
+        "__html": "body {
+  background: pink;
+}
+",
+      }
+    }
+    data-chunk="letters-A"
+  />,
+  <style
+    dangerouslySetInnerHTML={
+      Object {
+        "__html": "h1 {
+  color: cyan;
+}",
+      }
+    }
+    data-chunk="main"
+  />,
+]
+`),
+      )
+    })
+
+  })
+
+  describe('#getCssString', () => {
+    it('should return a string of the referenced css files as a promise', () => {
+      extractor.addChunk('letters-A')
+      expect.assertions(1)
+      return extractor.getCssString().then(data => expect(data).toMatchInlineSnapshot(`
+"body {
+  background: pink;
+}
+
+h1 {
+  color: cyan;
+}"
+`),
+      )
+    })
+    
   })
 
   describe('#getLinkTags', () => {
     it('should return main script tag without chunk', () => {
-      const extractor = new ChunkExtractor({ stats })
       expect(extractor.getLinkTags()).toMatchInlineSnapshot(`
 "<link data-chunk=\\"main\\" rel=\\"preload\\" as=\\"style\\" href=\\"/dist/node/main.css\\">
 <link data-chunk=\\"main\\" rel=\\"preload\\" as=\\"script\\" href=\\"/dist/node/main.js\\">
@@ -166,7 +241,6 @@ Array [
     })
 
     it('should return other chunks if referenced', () => {
-      const extractor = new ChunkExtractor({ stats })
       extractor.addChunk('letters-A')
       expect(extractor.getLinkTags()).toMatchInlineSnapshot(`
 "<link data-chunk=\\"letters-A\\" rel=\\"preload\\" as=\\"style\\" href=\\"/dist/node/letters-A.css\\">
@@ -181,7 +255,6 @@ Array [
 
   describe('#getLinkElements', () => {
     it('should return main script tag without chunk', () => {
-      const extractor = new ChunkExtractor({ stats })
       expect(extractor.getLinkElements()).toMatchInlineSnapshot(`
 Array [
   <link
@@ -213,7 +286,6 @@ Array [
     })
 
     it('should return other chunks if referenced', () => {
-      const extractor = new ChunkExtractor({ stats })
       extractor.addChunk('letters-A')
       expect(extractor.getLinkElements()).toMatchInlineSnapshot(`
 Array [
@@ -260,7 +332,6 @@ Array [
 
   describe('#requireEntryPoint', () => {
     it('should load the first entrypoint', () => {
-      const extractor = new ChunkExtractor({ stats })
       const x = extractor.requireEntrypoint()
       expect(x).toBe('hello')
     })

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+body {`
	`2`	`+ background: pink;`
	`3`	`+}`