feat: improve compatibility with webpack@5

BREAKING CHANGE: use `processAssets` hook for webpack@5 compatibility, it can create incompatibility with plugins that do not support webpack@5, please open an issue in their repositories

Author: evilebottnawi

.eslintignore

@@ -1,4 +1,5 @@
 /coverage
 /dist
 /node_modules
-/test/fixtures
+/test/fixtures
+/test/outputs

.gitignore

@@ -7,6 +7,7 @@ npm-debug.log*
 /local
 /reports
 /node_modules
+/test/outputs
 .DS_Store
 Thumbs.db
 .idea

.prettierignore

@@ -2,4 +2,5 @@
 /dist
 /node_modules
 /test/fixtures
-CHANGELOG.md
+/test/outputs
+CHANGELOG.md

src/Webpack4Cache.js

@@ -20,20 +20,27 @@ export default class Webpack4Cache {
     return Boolean(this.cacheDir);
   }
 
-  get(task) {
+  async get(task) {
     // eslint-disable-next-line no-param-reassign
     task.cacheIdent = task.cacheIdent || serialize(task.cacheKeys);
 
-    return cacache.get(this.cacheDir, task.cacheIdent).then(({ data }) => {
-      const result = JSON.parse(data);
+    let cachedResult;
 
-      result.output = Buffer.from(result.output);
+    try {
+      cachedResult = await cacache.get(this.cacheDir, task.cacheIdent);
+    } catch (ignoreError) {
+      // eslint-disable-next-line no-undefined
+      return undefined;
+    }
 
-      return result;
-    });
+    return Buffer.from(JSON.parse(cachedResult.data).data);
   }
 
-  store(task, data) {
-    return cacache.put(this.cacheDir, task.cacheIdent, JSON.stringify(data));
+  async store(task) {
+    return cacache.put(
+      this.cacheDir,
+      task.cacheIdent,
+      JSON.stringify(task.output)
+    );
   }
 }

src/Webpack5Cache.js

@@ -1,74 +1,22 @@
-// eslint-disable-next-line import/extensions,import/no-unresolved
-import getLazyHashedEtag from 'webpack/lib/cache/getLazyHashedEtag';
-
-import { util } from 'webpack';
-
 export default class Cache {
   // eslint-disable-next-line no-unused-vars
   constructor(compilation, ignored) {
-    this.compilation = compilation;
+    this.cache = compilation.getCache('CompressionWebpackPlugin');
   }
 
+  // eslint-disable-next-line class-methods-use-this
   isEnabled() {
-    return Boolean(this.compilation.cache);
-  }
-
-  createCacheIdent(task) {
-    const {
-      outputOptions: { hashSalt, hashDigest, hashDigestLength, hashFunction },
-    } = this.compilation;
-
-    const hash = util.createHash(hashFunction);
-
-    if (hashSalt) {
-      hash.update(hashSalt);
-    }
-
-    hash.update(JSON.stringify(task.cacheKeys));
-
-    const digest = hash.digest(hashDigest);
-    const cacheKeys = digest.substr(0, hashDigestLength);
-
-    return `${this.compilation.compilerPath}/CompressionPlugin/${cacheKeys}/${task.filename}`;
+    return true;
   }
 
-  get(task) {
-    // eslint-disable-next-line no-param-reassign
-    task.cacheIdent = task.cacheIdent || this.createCacheIdent(task);
+  async get(task) {
     // eslint-disable-next-line no-param-reassign
-    task.cacheETag = task.cacheETag || getLazyHashedEtag(task.assetSource);
+    task.eTag = task.eTag || this.cache.getLazyHashedEtag(task.assetSource);
 
-    return new Promise((resolve, reject) => {
-      this.compilation.cache.get(
-        task.cacheIdent,
-        task.cacheETag,
-        (err, result) => {
-          if (err) {
-            reject(err);
-          } else if (result) {
-            resolve(result);
-          } else {
-            reject();
-          }
-        }
-      );
-    });
+    return this.cache.getPromise(task.assetName, task.eTag);
   }
 
-  store(task, data) {
-    return new Promise((resolve, reject) => {
-      this.compilation.cache.store(
-        task.cacheIdent,
-        task.cacheETag,
-        data,
-        (err) => {
-          if (err) {
-            reject(err);
-          } else {
-            resolve(data);
-          }
-        }
-      );
-    });
+  async store(task) {
+    return this.cache.storePromise(task.assetName, task.eTag, task.output);
   }
 }