feat: emliminate output js when empty

src/__tests__/fixtures/basic-template-plugin-production/server.js

@@ -0,0 +1,8 @@
+const http = require("http");
+const test = require("./test.marko");
+
+http
+  .createServer((req, res) => {
+    test.render({}, res);
+  })
+  .listen(0);

src/__tests__/fixtures/basic-template-plugin-production/test.marko

@@ -0,0 +1 @@
+<h1>Hello World</h1>

src/__tests__/fixtures/basic-template-plugin-production/webpack.config.ts

@@ -0,0 +1,42 @@
+import * as path from "path";
+import * as webpack from "webpack";
+import MarkoPlugin from "../../../plugin";
+
+const markoPlugin = new MarkoPlugin();
+
+export default [
+  {
+    name: "server",
+    target: "async-node",
+    mode: "production",
+    entry: path.join(__dirname, "server.js"),
+    module: {
+      rules: [
+        {
+          test: /\.marko$/,
+          loader: "@marko/webpack/loader"
+        }
+      ]
+    },
+    plugins: [
+      new webpack.DefinePlugin({
+        "process.env.BUNDLE": true
+      }),
+      markoPlugin.server
+    ]
+  },
+  {
+    name: "browser",
+    target: "web",
+    mode: "production",
+    module: {
+      rules: [
+        {
+          test: /\.marko$/,
+          loader: "@marko/webpack/loader"
+        }
+      ]
+    },
+    plugins: [markoPlugin.browser]
+  }
+];

src/__tests__/main.ts

@@ -24,6 +24,7 @@ for (const [version, webpack] of Object.entries({ webpack4, webpack5 })) {
       test(`${name}`, async () => {
         const fixtureDir = path.join(fixturesDir, name);
         const snapshotDir = path.join(fixtureDir, "__snapshots__", version);
+        const remainingSnapshots = fs.readdirSync(snapshotDir);
         const configPath = path.join(fixtureDir, "webpack.config.ts");
         const { outputPath, outputFS, stats } = await compilation(
           webpack as typeof webpack4,
@@ -42,9 +43,32 @@ for (const [version, webpack] of Object.entries({ webpack4, webpack5 })) {
               path.join(outputPath, assetName),
               "utf-8"
             );
+            const snapshotName = prefixName + assetName;
+            const snapshotIndex = remainingSnapshots.indexOf(snapshotName);
 
-            expect(source).toMatchFile(
-              path.join(snapshotDir, prefixName + assetName)
+            if (
+              snapshotIndex == -1 &&
+              expect.getState().snapshotState._updateSnapshot !== "all"
+            ) {
+              throw new Error(`Missing snapshot: ${version}/${snapshotName}`);
+            } else {
+              // eslint-disable-next-line jest/no-conditional-expect
+              expect(source).toMatchFile(path.join(snapshotDir, snapshotName));
+              remainingSnapshots.splice(snapshotIndex, 1);
+            }
+          }
+        }
+
+        if (remainingSnapshots.length) {
+          if (expect.getState().snapshotState._updateSnapshot === "all") {
+            for (const snapshotName of remainingSnapshots) {
+              fs.unlinkSync(path.join(snapshotDir, snapshotName));
+            }
+          } else {
+            throw new Error(
+              `Unexpected snapshots for ${version}: ${remainingSnapshots.join(
+                ", "
+              )}`
             );
           }
         }

src/plugin/index.ts

@@ -288,6 +288,25 @@ export default class MarkoWebpackPlugin {
           });
         }
       );
+
+      compiler.hooks.afterCompile.tap(
+        "MarkWebpackBrowser:afterCompile",
+        compilation => {
+          for (const chunk of compilation.chunks) {
+            for (const assetName of chunk.files) {
+              const asset = compilation.assets[assetName];
+              if (asset.size() === 0) {
+                delete compilation.assets[assetName];
+                if (Array.isArray(chunk.files)) {
+                  chunk.files.splice(chunk.files.indexOf(assetName), 1);
+                } else {
+                  chunk.files.delete(assetName);
+                }
+              }
+            }
+          }
+        }
+      );
     };
   }
 }