Fixing source maps (#47)

* source maps test

* adding assets to parent compilation in right lifecycle hook

* switching to afterOptimize

* making sure that source maps are created

Author: prateekbh

src/index.js

@@ -148,32 +148,34 @@ class BabelEsmPlugin {
               return childProcessDone(childCompilation.errors[0]);
             }
 
-            compilation.assets = Object.assign(
-              childCompilation.assets,
-              compilation.assets,
-            );
-
-            compilation.namedChunkGroups = Object.assign(
-              childCompilation.namedChunkGroups,
-              compilation.namedChunkGroups,
-            );
-
-            const childChunkFileMap = childCompilation.chunks.reduce(
-              (chunkMap, chunk) => {
-                chunkMap[chunk.name] = chunk.files;
-                return chunkMap;
-              },
-              {},
-            );
-
-            compilation.chunks.forEach(chunk => {
-              const childChunkFiles = childChunkFileMap[chunk.name];
-
-              if (childChunkFiles) {
-                chunk.files.push(
-                  ...childChunkFiles.filter(v => !chunk.files.includes(v)),
-                );
-              }
+            compilation.hooks.afterOptimizeAssets.tap(PLUGIN_NAME, () => {
+              compilation.assets = Object.assign(
+                childCompilation.assets,
+                compilation.assets,
+              );
+
+              compilation.namedChunkGroups = Object.assign(
+                childCompilation.namedChunkGroups,
+                compilation.namedChunkGroups,
+              );
+
+              const childChunkFileMap = childCompilation.chunks.reduce(
+                (chunkMap, chunk) => {
+                  chunkMap[chunk.name] = chunk.files;
+                  return chunkMap;
+                },
+                {},
+              );
+
+              compilation.chunks.forEach(chunk => {
+                const childChunkFiles = childChunkFileMap[chunk.name];
+
+                if (childChunkFiles) {
+                  chunk.files.push(
+                    ...childChunkFiles.filter(v => !chunk.files.includes(v)),
+                  );
+                }
+              });
             });
 
             childProcessDone();

tests/babel-preset-modules/fixtures/index.js

@@ -25,6 +25,11 @@ test('esm files are being generated', async t => {
   const compiler = getCompiler(config);
   const { hash } = await runWebpack(compiler);
   const files = fs.readdirSync(`${__dirname}/output/`);
-  t.is(files.length, 2);
-  t.deepEqual(files, [`index.${hash}.es6.js`, `index.${hash}.js`]);
+  t.is(files.length, 4);
+  t.deepEqual(files, [
+    `index.${hash}.es6.js`,
+    `index.${hash}.es6.js.map`,
+    `index.${hash}.js`,
+    `index.${hash}.js.map`,
+  ]);
 });