Add augmentChunkHash hook for proper content hashing

package.json

@@ -41,7 +41,7 @@
     "jest": "^23.6.0",
     "less": "^2.7.3",
     "node-sass": "^4.13.1",
-    "rollup": "^1.1.2",
+    "rollup": "^1.32.0",
     "stylus": "^0.54.5",
     "sugarss": "^1.0.1",
     "xo": "^0.18.2"

src/index.js

@@ -101,6 +101,15 @@ export default (options = {}) => {
       }
     },
 
+    augmentChunkHash() {
+      if (extracted.size === 0) return
+      const extractedValue = Array.from(extracted).reduce((obj, [key, value]) => ({
+        ...obj,
+        [key]: value
+      }), {})
+      return JSON.stringify(extractedValue)
+    },
+
     async generateBundle(opts, bundle) {
       if (
         extracted.size === 0 ||

test/__snapshots__/index.test.js.snap

@@ -635,9 +635,10 @@ const stylesheet=\\".style_foo {\\\\n  color: red;\\\\n}\\\\n\\\\n.style_new {\\
 styleInject(css);
 
 var style$1 = /*#__PURE__*/Object.freeze({
+  __proto__: null,
   foo: foo,
   $new$: $new$,
-  default: style,
+  'default': style,
   stylesheet: stylesheet
 });
 
@@ -683,9 +684,10 @@ const stylesheet=\\".style_foo {\\\\n  color: red;\\\\n}\\\\n\\\\n.style_new {\\
 styleInject(css);
 
 var style$1 = /*#__PURE__*/Object.freeze({
+  __proto__: null,
   foohacked: foohacked,
   newhacked: newhacked,
-  default: style,
+  'default': style,
   stylesheet: stylesheet
 });
 

test/index.test.js

@@ -334,3 +334,31 @@ test('onExtract', async () => {
   expect(await res.jsCode()).toMatchSnapshot()
   expect(await res.hasCssFile()).toBe(false)
 })
+
+test('augmentChunkHash', async () => {
+  const outDir = fixture('dist', 'augmentChunkHash')
+  const cssFiles = ['simple/foo.css', 'simple/foo.css', 'simple/bar.css']
+
+  const outputFiles = []
+  /* eslint-disable no-await-in-loop */
+  for (const file of cssFiles) {
+    const newBundle = await rollup({
+      input: fixture(file),
+      plugins: [postcss({ extract: true })]
+    })
+    const entryFileName = file.split('.')[0]
+    const { output } = await newBundle.write({
+      dir: outDir,
+      entryFileNames: `${entryFileName}.[hash].css`
+    })
+    outputFiles.push(output[0])
+  }
+  const [fooOne, fooTwo, barOne] = outputFiles
+
+  const fooHash = fooOne.fileName.split('.')[1]
+  expect(fooHash).toBeTruthy() // Verify that [hash] part of `foo.[hash].css` is truthy
+  expect(fooOne.fileName).toEqual(fooTwo.fileName) // Verify that the foo hashes to the same fileName
+
+  const barHash = barOne.fileName.split('.')[1]
+  expect(barHash).not.toEqual(fooHash) // Verify that foo and bar does not hash to the same
+})

yarn.lock

@@ -646,6 +646,11 @@
     lodash "^4.17.10"
     to-fast-properties "^2.0.0"
 
+"@types/estree@*":
+  version "0.0.42"
+  resolved "https://registry.yarnpkg.com/@types/estree/-/estree-0.0.42.tgz#8d0c1f480339efedb3e46070e22dd63e0430dd11"
+  integrity sha512-K1DPVvnBCPxzD+G51/cxVIoc2X8uUVl1zpJeE6iKcgHMj4+tbat5Xu4TjV7v2QSDbIeAfLi2hIk+u2+s0MlpUQ==
+
 "@types/estree@0.0.39":
   version "0.0.39"
   resolved "https://registry.npmjs.org/@types/estree/-/estree-0.0.39.tgz#e177e699ee1b8c22d23174caaa7422644389509f"
@@ -706,6 +711,11 @@ acorn@^6.0.1, acorn@^6.0.5:
   resolved "https://registry.npmjs.org/acorn/-/acorn-6.0.5.tgz#81730c0815f3f3b34d8efa95cb7430965f4d887a"
   integrity sha512-i33Zgp3XWtmZBMNvCr4azvOFeWVw1Rk6p3hfi3LUDvIFraOMywb1kAtrbi+med14m4Xfpqm3zRZMT+c0FNE7kg==
 
+acorn@^7.1.0:
+  version "7.1.1"
+  resolved "https://registry.yarnpkg.com/acorn/-/acorn-7.1.1.tgz#e35668de0b402f359de515c5482a1ab9f89a69bf"
+  integrity sha512-add7dgA5ppRPxCFJoAGfMDi7PIBXq1RtGo7BhbLaxwrXPOmw8gq48Y9ozT01hUKy9byMjlR20EJhu5zlkErEkg==
+
 ajv-keywords@^1.0.0:
   version "1.5.1"
   resolved "https://registry.npmjs.org/ajv-keywords/-/ajv-keywords-1.5.1.tgz#314dd0a4b3368fad3dfcdc54ede6171b886daf3c"
@@ -6383,6 +6393,15 @@ rollup@^1.1.2:
     "@types/node" "*"
     acorn "^6.0.5"
 
+rollup@^1.32.0:
+  version "1.32.0"
+  resolved "https://registry.yarnpkg.com/rollup/-/rollup-1.32.0.tgz#c65ce134850aca1ce595fcac07d1dc5d53bf227c"
+  integrity sha512-ab2tF5pdDqm2zuI8j02ceyrJSScl9V2C24FgWQ1v1kTFTu1UrG5H0hpP++mDZlEFyZX4k0chtGEHU2i+pAzBgA==
+  dependencies:
+    "@types/estree" "*"
+    "@types/node" "*"
+    acorn "^7.1.0"
+
 rsvp@^3.3.3:
   version "3.6.2"
   resolved "https://registry.npmjs.org/rsvp/-/rsvp-3.6.2.tgz#2e96491599a96cde1b515d5674a8f7a91452926a"