Bundle buddy reporter (#4648)

* WIP: bundle buddy reporter

* Update BundleBuddyReporter.js

* Add @parcel/reporter-bundle-analyzer to package.json

* Update BundleBuddyReporter.js

* fix lint

Co-authored-by: Jasper De Moor <jasperdemoor@gmail.com>

packages/configs/default/index.json

@@ -58,6 +58,7 @@
   "reporters": [
     "@parcel/reporter-cli",
     "@parcel/reporter-dev-server",
-    "@parcel/reporter-bundle-analyzer"
+    "@parcel/reporter-bundle-analyzer",
+    "@parcel/reporter-bundle-buddy"
   ]
 }

packages/configs/default/package.json

@@ -27,6 +27,7 @@
     "@parcel/packager-raw-url": "^2.0.0-alpha.3.1",
     "@parcel/packager-ts": "^2.0.0-alpha.3.1",
     "@parcel/reporter-bundle-analyzer": "^2.0.0-alpha.3.1",
+    "@parcel/reporter-bundle-buddy": "^2.0.0-alpha.3.1",
     "@parcel/reporter-cli": "^2.0.0-alpha.3.1",
     "@parcel/reporter-dev-server": "^2.0.0-alpha.3.1",
     "@parcel/resolver-default": "^2.0.0-alpha.3.1",

packages/reporters/bundle-buddy/package.json

@@ -0,0 +1,21 @@
+{
+  "name": "@parcel/reporter-bundle-buddy",
+  "version": "2.0.0-alpha.3.1",
+  "license": "MIT",
+  "publishConfig": {
+    "access": "public"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/parcel-bundler/parcel.git"
+  },
+  "main": "lib/BundleBuddyReporter.js",
+  "source": "src/BundleBuddyReporter.js",
+  "engines": {
+    "node": ">= 10.0.0",
+    "parcel": "^2.0.0-alpha.1.1"
+  },
+  "dependencies": {
+    "@parcel/plugin": "^2.0.0-alpha.3.1"
+  }
+}

packages/reporters/bundle-buddy/src/BundleBuddyReporter.js

@@ -0,0 +1,51 @@
+// @flow strict-local
+import type {NamedBundle} from '@parcel/types';
+import {Reporter} from '@parcel/plugin';
+import path from 'path';
+
+export default new Reporter({
+  async report({event, options}) {
+    if (event.type !== 'buildSuccess' || process.env.BUNDLE_BUDDY == null) {
+      return;
+    }
+
+    let bundlesByTarget: Map<string, Array<NamedBundle>> = new Map();
+    for (let bundle of event.bundleGraph.getBundles()) {
+      if (!bundle.isInline) {
+        let bundles = bundlesByTarget.get(bundle.target.distDir);
+        if (!bundles) {
+          bundles = [];
+          bundlesByTarget.set(bundle.target.distDir, bundles);
+        }
+
+        bundles.push(bundle);
+      }
+    }
+
+    for (let [targetDir, bundles] of bundlesByTarget) {
+      let out = [];
+
+      for (let bundle of bundles) {
+        bundle.traverseAssets(asset => {
+          let deps = event.bundleGraph.getDependencies(asset);
+          for (let dep of deps) {
+            let resolved = event.bundleGraph.getDependencyResolution(dep);
+            if (!resolved) {
+              continue;
+            }
+
+            out.push({
+              source: path.relative(options.projectRoot, asset.filePath),
+              target: path.relative(options.projectRoot, resolved.filePath),
+            });
+          }
+        });
+      }
+
+      await options.outputFS.writeFile(
+        `${targetDir}/bundle-buddy.json`,
+        JSON.stringify(out),
+      );
+    }
+  },
+});