Add bundle-size check action (#3454)

* feat: add scripts action, bundle-size checker

* chore: trigger action

* fix: update prefix logic

7 files changed, 135 insertions, 6 deletions

diff --git a/.github/scripts/bundle-size.mjs b/.github/scripts/bundle-size.mjs
new file mode 100644
index 000000000..4166735a9
--- /dev/null
+++ b/.github/scripts/bundle-size.mjs
@@ -0,0 +1,81 @@
+import { build } from 'esbuild';
+
+const CLIENT_RUNTIME_PATH = 'packages/astro/src/runtime/client/';
+
+function formatBytes(bytes, decimals = 2) {
+    if (bytes === 0) return '0 B';
+
+    const k = 1024;
+    const dm = decimals < 0 ? 0 : decimals;
+    const sizes = ['B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'];
+
+    const i = Math.floor(Math.log(bytes) / Math.log(k));
+
+    return parseFloat((bytes / Math.pow(k, i)).toFixed(dm)) + ' ' + sizes[i];
+}
+
+export default async function checkBundleSize({ github, context }) {
+	const PR_NUM = context.payload.pull_request.number;
+	const SHA = context.payload.pull_request.head.sha;
+
+	const { data: files } = await github.rest.pulls.listFiles({
+		...context.repo,
+		pull_number: PR_NUM,
+	});
+	const clientRuntimeFiles = files.filter(({ filename }) => filename.startsWith(CLIENT_RUNTIME_PATH));
+	if (clientRuntimeFiles.length === 0) return;
+	
+	const table = [
+		'| File | Old Size | New Size | Change |',
+		'| ---- | -------- | -------- | ------ |',
+	];
+	const output = await bundle(clientRuntimeFiles);
+	
+	for (let [filename, { oldSize, newSize, sourceFile }] of Object.entries(output)) {
+		filename = filename !== 'hmr' ? `client:${filename}` : filename;
+		const prefix = (newSize - oldSize) === 0 ? '' : (newSize - oldSize) > 0 ? '+ ' : '- ';
+		const change = `${prefix}${formatBytes(newSize - oldSize)}`;
+		table.push(`| [\`${filename}\`](https://github.com/${context.repo.owner}/${context.repo.repo}/tree/${context.payload.pull_request.head.ref}/${sourceFile}) | ${formatBytes(oldSize)} | ${formatBytes(newSize)} | ${change} |`);
+	}
+
+	const { data: comments } = await github.rest.issues.listComments({
+		...context.repo,
+		issue_number: PR_NUM
+	})
+	const comment = comments.find(comment => comment.user.login === 'github-actions[bot]' && comment.body.includes('Bundle Size Check'));
+	const method = comment ? 'updateComment' : 'createComment';
+	const payload = comment ? { comment_id: comment.id } : { issue_number: PR_NUM };
+	await github.rest.issues[method]({
+		...context.repo,
+		...payload,
+		body: `###  ⚖️  Bundle Size Check
+
+Latest commit: ${SHA}
+
+${table.join('\n')}`,
+	});
+}
+
+async function bundle(files) {
+	const { metafile } = await build({
+		entryPoints: [...files.map(({ filename }) => filename), ...files.map(({ filename }) => `main/${filename}`)],
+		bundle: true,
+		minify: true,
+		sourcemap: false,
+		target: ['es2018'],
+		outdir: 'out',
+		metafile: true,
+	})
+
+	return Object.entries(metafile.outputs).reduce((acc, [filename, info]) => {
+		filename = filename.slice('out/'.length);
+		if (filename.startsWith('main/')) {
+			filename = filename.slice('main/'.length).replace(CLIENT_RUNTIME_PATH, '').replace('.js', '');
+			const oldSize = info.bytes;
+			return Object.assign(acc, { [filename]: Object.assign(acc[filename] ?? {}, { oldSize }) });
+		}
+		filename = filename.replace(CLIENT_RUNTIME_PATH, '').replace('.js', '');
+		const newSize = info.bytes;
+		return Object.assign(acc, { [filename]: Object.assign(acc[filename] ?? {}, { newSize, sourceFile: Object.keys(info.inputs).find(src => src.endsWith('.ts')) }) });
+	}, {});
+}
diff --git a/.github/workflows/scripts.yml b/.github/workflows/scripts.yml
new file mode 100644
index 000000000..40a29ee61
--- /dev/null
+++ b/.github/workflows/scripts.yml
@@ -0,0 +1,48 @@
+name: Scripts
+
+on:
+  pull_request:
+    branches:
+      - 'main'
+
+# Automatically cancel in-progress actions on the same branch
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event_name == 'pull_request_target' && github.head_ref || github.ref }}
+  cancel-in-progress: true
+
+defaults:
+  run:
+    shell: bash
+
+jobs:
+  bundle:
+    name: Bundle Size
+    runs-on: ubuntu-latest
+    steps: 
+      - name: Checkout Repo
+        uses: actions/checkout@v2
+
+      - name: Checkout Main into tmp
+        uses: actions/checkout@v2
+        with:
+          ref: main
+          path: main
+
+      - name: Setup PNPM
+        uses: pnpm/action-setup@v2.2.1
+
+      - name: Setup Node
+        uses: actions/setup-node@v3
+        with:
+          node-version: 16
+          cache: 'pnpm'
+
+      - name: Install dependencies
+        run: pnpm install
+      
+      - name: Check Bundle Size
+        uses: actions/github-script@v6
+        with:
+          script: |
+            const { default: script } = await import('${{ github.workspace }}/.github/scripts/bundle-size.mjs')
+            await script({ github, context })
diff --git a/packages/astro/src/runtime/client/idle.ts b/packages/astro/src/runtime/client/idle.ts
index 627d896db..e1e1c5b2f 100644
--- a/packages/astro/src/runtime/client/idle.ts
+++ b/packages/astro/src/runtime/client/idle.ts
@@ -1,7 +1,7 @@
 import type { GetHydrateCallback, HydrateOptions } from '../../@types/astro';
 
 /**
- * Hydrate this component as soon as the main thread is free
+ * Hydrate this component as soon as the main thread is free!
  * (or after a short delay, if `requestIdleCallback`) isn't supported
  */
 export default async function onIdle(
diff --git a/packages/astro/src/runtime/client/load.ts b/packages/astro/src/runtime/client/load.ts
index cf4cd83af..d969b4061 100644
--- a/packages/astro/src/runtime/client/load.ts
+++ b/packages/astro/src/runtime/client/load.ts
@@ -1,7 +1,7 @@
 import type { GetHydrateCallback, HydrateOptions } from '../../@types/astro';
 
 /**
- * Hydrate this component immediately
+ * Hydrate this component immediately!
  */
 export default async function onLoad(
 	astroId: string,
diff --git a/packages/astro/src/runtime/client/media.ts b/packages/astro/src/runtime/client/media.ts
index 32e883908..edaa9a433 100644
--- a/packages/astro/src/runtime/client/media.ts
+++ b/packages/astro/src/runtime/client/media.ts
@@ -1,7 +1,7 @@
 import type { GetHydrateCallback, HydrateOptions } from '../../@types/astro';
 
 /**
- * Hydrate this component when a matching media query is found
+ * Hydrate this component when a matching media query is found!
  */
 export default async function onMedia(
 	astroId: string,
diff --git a/packages/astro/src/runtime/client/only.ts b/packages/astro/src/runtime/client/only.ts
index 6400d44b8..04937c608 100644
--- a/packages/astro/src/runtime/client/only.ts
+++ b/packages/astro/src/runtime/client/only.ts
@@ -1,9 +1,9 @@
 import type { GetHydrateCallback, HydrateOptions } from '../../@types/astro';
 
 /**
- * Hydrate this component immediately
+ * Hydrate this component only on the client
  */
-export default async function onLoad(
+export default async function onOnly(
 	astroId: string,
 	options: HydrateOptions,
 	getHydrateCallback: GetHydrateCallback
diff --git a/packages/astro/src/runtime/client/visible.ts b/packages/astro/src/runtime/client/visible.ts
index e0c1fdc73..e9c3e3310 100644
--- a/packages/astro/src/runtime/client/visible.ts
+++ b/packages/astro/src/runtime/client/visible.ts
@@ -1,7 +1,7 @@
 import type { GetHydrateCallback, HydrateOptions } from '../../@types/astro';
 
 /**
- * Hydrate this component when one of it's children becomes visible.
+ * Hydrate this component when one of it's children becomes visible!
  * We target the children because `astro-root` is set to `display: contents`
  * which doesn't work with IntersectionObserver
  */