From ca29537bbcdf2a36c5ecf118a6de01bdf3f8721b Mon Sep 17 00:00:00 2001
From: Aaron Klinker <aklinker1@users.noreply.github.com>
Date: Fri, 23 Jun 2023 21:17:41 -0500
Subject: [PATCH] feat: Virtualized content script entrypoint

Generalized the background logic so it can be reused with mulitple entrypoint types
---
 package.json                          |  3 ++-
 src/utils/buildEntrypoints.ts         |  8 +++++-
 src/utils/getInternalConfig.ts        |  2 ++
 src/vite-plugins/index.ts             |  1 +
 src/vite-plugins/virtualEntrypoint.ts | 35 +++++++++++++++++++++++++++
 templates/template-vars.d.ts          | 11 +++++++++
 templates/virtual-background.ts       | 13 ++++++++++
 templates/virtual-content-script.ts   |  9 +++++++
 8 files changed, 80 insertions(+), 2 deletions(-)
 create mode 100644 src/vite-plugins/virtualEntrypoint.ts
 create mode 100644 templates/template-vars.d.ts
 create mode 100644 templates/virtual-background.ts
 create mode 100644 templates/virtual-content-script.ts

diff --git a/package.json b/package.json
index 5401bd93..15c50341 100644
--- a/package.json
+++ b/package.json
@@ -14,7 +14,8 @@
   "author": "Aaron Klinker",
   "license": "MIT",
   "files": [
-    "dist"
+    "dist",
+    "templates"
   ],
   "bin": "dist/cli/index.cjs",
   "main": "./dist/index.cjs",
diff --git a/src/utils/buildEntrypoints.ts b/src/utils/buildEntrypoints.ts
index 8925bf2d..4a865037 100644
--- a/src/utils/buildEntrypoints.ts
+++ b/src/utils/buildEntrypoints.ts
@@ -32,10 +32,16 @@ async function buildSingleEntrypoint(
   entrypoint: Entrypoint,
   config: InternalConfig,
 ): Promise<BuildOutput> {
+  // Should this entrypoint be wrapped by the vite-plugins/virtualEntrypoint plugin?
+  const isVirtual = ['background', 'content-script'].includes(entrypoint.type);
+  const entry = isVirtual
+    ? `virtual:exvite-${entrypoint.type}?${entrypoint.inputPath}`
+    : entrypoint.inputPath;
+
   const libMode: vite.InlineConfig = {
     build: {
       lib: {
-        entry: entrypoint.inputPath,
+        entry,
         formats: ['iife'],
         name: entrypoint.name,
         fileName: entrypoint.name,
diff --git a/src/utils/getInternalConfig.ts b/src/utils/getInternalConfig.ts
index 311b04fd..61692be2 100644
--- a/src/utils/getInternalConfig.ts
+++ b/src/utils/getInternalConfig.ts
@@ -79,6 +79,8 @@ export async function getInternalConfig(
   merged.vite.plugins.push(plugins.download(merged));
   merged.vite.plugins.push(plugins.devHtmlPrerender(merged));
   merged.vite.plugins.push(plugins.unimport(merged));
+  merged.vite.plugins.push(plugins.virtualEntrypoin('background'));
+  merged.vite.plugins.push(plugins.virtualEntrypoin('content-script'));
 
   return merged;
 }
diff --git a/src/vite-plugins/index.ts b/src/vite-plugins/index.ts
index a18d3ee4..83ef53c8 100644
--- a/src/vite-plugins/index.ts
+++ b/src/vite-plugins/index.ts
@@ -2,3 +2,4 @@ export * from './download';
 export * from './unimport';
 export * from './multipageMove';
 export * from './devHtmlPrerender';
+export * from './virtualEntrypoint';
diff --git a/src/vite-plugins/virtualEntrypoint.ts b/src/vite-plugins/virtualEntrypoint.ts
new file mode 100644
index 00000000..2dcbcc6f
--- /dev/null
+++ b/src/vite-plugins/virtualEntrypoint.ts
@@ -0,0 +1,35 @@
+import { Plugin } from 'vite';
+import { Entrypoint } from '../types';
+import fs from 'fs-extra';
+import { resolve } from 'path';
+
+/**
+ * Wraps a user's entrypoint with a vitual version with additional logic.
+ */
+export function virtualEntrypoin(type: Entrypoint['type']): Plugin {
+  const virtualId = `virtual:exvite-${type}?`;
+  const resolvedVirtualId = `\0${virtualId}`;
+
+  return {
+    name: `exvite:virtual-entrypoint`,
+    resolveId(id) {
+      // Id doesn't start with prefix, it looks like this:
+      // /path/to/project/virtual:background?/path/to/project/entrypoints/background.ts
+      const index = id.indexOf(virtualId);
+      if (index === -1) return;
+
+      const inputPath = id.substring(index + virtualId.length);
+      return resolvedVirtualId + inputPath;
+    },
+    async load(id) {
+      if (!id.startsWith(resolvedVirtualId)) return;
+
+      const inputPath = id.replace(resolvedVirtualId, '');
+      const template = await fs.readFile(
+        resolve(`node_modules/exvite/templates/virtual-${type}.ts`),
+        'utf-8',
+      );
+      return template.replaceAll('{{moduleId}}', inputPath);
+    },
+  };
+}
diff --git a/templates/template-vars.d.ts b/templates/template-vars.d.ts
new file mode 100644
index 00000000..b62adf05
--- /dev/null
+++ b/templates/template-vars.d.ts
@@ -0,0 +1,11 @@
+// Types required to make templates happy.
+
+declare module '*?raw' {
+  const content: any;
+  export default content;
+}
+
+declare module '{{moduleId}}' {
+  const variable: any;
+  export default variable;
+}
diff --git a/templates/virtual-background.ts b/templates/virtual-background.ts
new file mode 100644
index 00000000..a427d94e
--- /dev/null
+++ b/templates/virtual-background.ts
@@ -0,0 +1,13 @@
+import definition from '{{moduleId}}';
+
+try {
+  const res = definition.main();
+  if (res instanceof Promise) {
+    console.warn(
+      "The background's main() function return a promise, but it must be synchonous",
+    );
+  }
+} catch (err) {
+  console.error('The background script crashed on startup!\n\n', err);
+  throw err;
+}
diff --git a/templates/virtual-content-script.ts b/templates/virtual-content-script.ts
new file mode 100644
index 00000000..1a167622
--- /dev/null
+++ b/templates/virtual-content-script.ts
@@ -0,0 +1,9 @@
+import definition from '{{moduleId}}';
+
+(async () => {
+  try {
+    await definition.main();
+  } catch (err) {
+    console.error('The content script crashed on startup!\n\n', err);
+  }
+})();