Adding an option to append a content hash to the end of font files for cache-busting on glyph changes

lib/index.js

@@ -1,5 +1,6 @@
 const fs = require('fs')
 const path = require('path')
+const crypto = require('crypto')
 const log = require('debug')('fontmin-webpack')
 
 const _ = require('lodash')
@@ -27,6 +28,7 @@ class FontminPlugin {
         autodetect: true,
         allowedFilesRegex: null,
         skippedFilesRegex: null,
+        appendHash: false,
       },
       options,
     )
@@ -189,6 +191,7 @@ class FontminPlugin {
   onAdditionalAssets(compilation) {
     const allowedFiles = this._options.allowedFilesRegex
     const skippedFiles = this._options.skippedFilesRegex
+    const appendHash = this._options.appendHash
     const fontFiles = this.findFontFiles(compilation)
     const glyphsInCss = this.findUnicodeGlyphs(compilation)
     log(`found ${glyphsInCss.length} glyphs in CSS`)
@@ -219,13 +222,38 @@ class FontminPlugin {
         .then(files => {
           files.forEach(file => {
             if (file.buffer.length > file.minified.length) {
-              compilation.assets[file.asset] = new RawSource(file.minified)
+              if (appendHash) {
+                const newAssetName = this.appendMinifiedFileHash(file)
+                compilation.assets[newAssetName] = new RawSource(file.minified)
+                this.hashifyFontReferences(file.asset, newAssetName, compilation.assets)
+                delete compilation.assets[file.asset]
+              } else {
+                compilation.assets[file.asset] = new RawSource(file.minified)
+              }
             }
           })
         })
     }, Promise.resolve())
   }
 
+  appendMinifiedFileHash(file) {
+    const fileHash = crypto.createHash('md5').update(file.minified).digest('hex')
+    return file.asset.split('.').join(`-${fileHash}.`)
+  }
+
+  hashifyFontReferences(oldAssetName, newAssetName, assets) {
+    Object.keys(assets).forEach(
+      asset => {
+        const oldAssetNameRegex = new RegExp(oldAssetName.replace('.', '\\.'), 'g')
+        const assetSource = assets[asset].source().toString()
+
+        if (assetSource.match(oldAssetNameRegex)) {
+          assets[asset] = new RawSource(assetSource.replace(oldAssetNameRegex, newAssetName))
+        }
+      }
+    )
+  }
+
   apply(compiler) {
     compiler.hooks.thisCompilation.tap('FontminPlugin', compilation => {
       compilation.hooks.additionalAssets.tapPromise('FontminPlugin', () => {

test/index.test.js

@@ -239,4 +239,19 @@ describe('FontminPlugin', () => {
       expect(svg.stats.size).to.be.equal(svgOriginal.stats.size)
     })
   })
+
+  describe('FontAwesome with appendHash option', () => {
+    it('should run successfully', function (done) {
+      this.timeout(60000)
+      const plugin = new Plugin({appendHash: true})
+      const config = _.cloneDeep(baseConfig)
+      testWithConfig(_.assign(config, {plugins: [plugin]}), done)
+    })
+
+    it('should append the hash to the ends of all refrences in all assets', () => {
+      const out = fs.readFileSync(DIST_FOLDER + '/out.js').toString()
+      fontStats.forEach(file => expect(out.match(file.filename)).to.be.ok)
+      fontStats.forEach(file => expect(out.match(file.filename.replace(/-([a-z]|[0-9])+\./, '.'))).to.not.be.ok)
+    })
+  })
 })