fix: nothing minifying salts no embedded-source hash either

The tap varies a module's hash on the minimizers, so an instance with none of them renamed files it never rewrote — the same defect the chunk hash had.

Author: alexander-akait

src/index.js

@@ -2413,7 +2413,10 @@ class MinimizerPlugin {
         /** @type {EmbeddedSourceHooks} */
         (/** @type {unknown} */ (compilation.hooks));
 
+      // Nothing minifying rewrites no embedded source either, and salting the
+      // module hash would rename a file this instance never touches.
       if (
+        this.minimizers().length > 0 &&
         embeddedHooks.renderEmbeddedSource &&
         embeddedHooks.embeddedSourceHash
       ) {

test/embedded-source.test.js

@@ -273,6 +273,45 @@ describe("embedded source", () => {
     );
   });
 
+  it("leaves the module hash alone where `minify` is an empty list", async () => {
+    /**
+     * @param {boolean} withPlugin whether to apply the plugin
+     * @returns {Promise<string[]>} the emitted names
+     */
+    const namesFrom = async (withPlugin) => {
+      const compiler = getCompiler({
+        entry: fixture("entry-css.js"),
+        target: "node",
+        output: {
+          path: path.resolve(__dirname, "./dist"),
+          filename: "[name].[contenthash].js",
+        },
+        experiments: { css: true },
+        module: {
+          rules: [
+            {
+              test: /\.css$/,
+              type: "css/auto",
+              parser: { exportType: "text" },
+            },
+          ],
+        },
+      });
+
+      if (withPlugin) {
+        new MinimizerPlugin({ test: /.*/, minify: [] }).apply(compiler);
+      }
+
+      const stats = await compile(compiler);
+
+      return Object.keys(stats.compilation.assets).sort();
+    };
+
+    // The embedded-source tap varies the module hash on the minimizers, and an
+    // instance with none of them rewrites nothing for it to vary on.
+    expect(await namesFrom(true)).toEqual(await namesFrom(false));
+  });
+
   it("dispatches by the language a minimizer declares, not by `test`", async () => {
     const compiler = getCompiler({
       entry: fixture("entry-css.js"),