feat: add hot-hook/register entrypoint loader

examples/hono/package.json

@@ -3,7 +3,7 @@
   "private": true,
   "type": "module",
   "scripts": {
-    "dev:tsnode": "hot-runner --node-args=\"--import=./tsnode.esm.js\" bin/start.ts",
+    "dev:tsnode": "hot-runner --node-args=--import=./tsnode.esm.js --node-args=--import=hot-hook/register src/index.tsx",
     "dev:tsx": "hot-runner --node-args=\"--import=tsx\" bin/start.ts"
   },
   "devDependencies": {
@@ -14,5 +14,11 @@
   "dependencies": {
     "@hono/node-server": "^1.9.0",
     "hono": "^4.1.4"
+  },
+  "hot-hook": {
+    "root": "./bin/server.ts",
+    "boundaries": [
+      "./views/**/*.tsx"
+    ]
   }
 }

examples/hono/src/index.tsx

@@ -27,7 +27,7 @@ console.log('Ready to serve requests')
 const app = new Hono()
 
 app.get('/', async (c) => {
-  const { Home } = await import('./views/home.js', { with: { hot: 'true' } })
+  const { Home } = await import('./views/home.js')
   return c.html(<Home />)
 })
 

packages/hot_hook/package.json

@@ -11,7 +11,7 @@
   "exports": {
     ".": "./build/src/hot.js",
     "./loader": "./build/src/loader.js",
-    "./runner": "./build/src/runner.js",
+    "./register": "./build/src/register.js",
     "./import-meta": {
       "types": "./import-meta.d.ts"
     }
@@ -33,7 +33,8 @@
   "dependencies": {
     "chokidar": "^3.6.0",
     "fast-glob": "^3.3.2",
-    "picomatch": "^4.0.2"
+    "picomatch": "^4.0.2",
+    "read-package-up": "^11.0.0"
   },
   "author": "Julien Ripouteau <[email protected]>",
   "license": "MIT",

packages/hot_hook/src/dependency_tree.ts

@@ -39,12 +39,16 @@ export default class DependencyTree {
   #tree!: FileNode
   #pathMap: Map<string, FileNode> = new Map()
 
-  constructor(options: { root: string }) {
+  constructor(options: { root?: string }) {
+    if (options.root) this.addRoot(options.root)
+  }
+
+  addRoot(path: string) {
     this.#tree = {
       version: 0,
       parents: null,
       reloadable: false,
-      path: options.root,
+      path: path,
       dependents: new Set(),
       dependencies: new Set(),
     }

packages/hot_hook/src/loader.ts

@@ -11,25 +11,34 @@ import DependencyTree from './dependency_tree.js'
 import { InitializeHookOptions } from './types.js'
 
 export class HotHookLoader {
-  #projectRoot: string
+  #options: InitializeHookOptions
+  #projectRoot!: string
   #messagePort?: MessagePort
-  #watcher: chokidar.FSWatcher
-  #pathIgnoredMatcher: Matcher
+  #watcher!: chokidar.FSWatcher
+  #pathIgnoredMatcher!: Matcher
   #dependencyTree: DependencyTree
-  #hardcodedBoundaryMatcher: Matcher
+  #hardcodedBoundaryMatcher!: Matcher
 
   constructor(options: InitializeHookOptions) {
-    this.#projectRoot = dirname(options.root)
+    this.#options = options
     this.#messagePort = options.messagePort
 
-    this.#watcher = this.#createWatcher().add(options.root)
-    this.#pathIgnoredMatcher = new Matcher(this.#projectRoot, options.ignore)
-    this.#hardcodedBoundaryMatcher = new Matcher(this.#projectRoot, options.boundaries)
+    if (options.root) this.#initialize(options.root)
 
     this.#dependencyTree = new DependencyTree({ root: options.root })
     this.#messagePort?.on('message', (message) => this.#onMessage(message))
   }
 
+  /**
+   * Initialize the class with the provided root path.
+   */
+  #initialize(root: string) {
+    this.#projectRoot = dirname(root)
+    this.#watcher = this.#createWatcher().add(root)
+    this.#pathIgnoredMatcher = new Matcher(this.#projectRoot, this.#options.ignore)
+    this.#hardcodedBoundaryMatcher = new Matcher(this.#projectRoot, this.#options.boundaries)
+  }
+
   /**
    * When a message is received from the main thread
    */
@@ -153,13 +162,19 @@ export class HotHookLoader {
     }
 
     const resultPath = fileURLToPath(resultUrl)
-    const parentPath = fileURLToPath(parentUrl)
-
-    const isHardcodedBoundary = this.#hardcodedBoundaryMatcher.match(resultPath)
-    const reloadable = context.importAttributes.hot === 'true' ? true : isHardcodedBoundary
+    const isRoot = !parentUrl
+    if (isRoot) {
+      this.#dependencyTree.addRoot(resultPath)
+      this.#initialize(resultPath)
+      return result
+    } else {
+      const parentPath = fileURLToPath(parentUrl)
+      const isHardcodedBoundary = this.#hardcodedBoundaryMatcher.match(resultPath)
+      const reloadable = context.importAttributes.hot === 'true' ? true : isHardcodedBoundary
 
-    this.#dependencyTree.addDependency(parentPath, { path: resultPath, reloadable })
-    this.#dependencyTree.addDependent(resultPath, parentPath)
+      this.#dependencyTree.addDependency(parentPath, { path: resultPath, reloadable })
+      this.#dependencyTree.addDependent(resultPath, parentPath)
+    }
 
     if (this.#pathIgnoredMatcher.match(resultPath)) {
       return result

packages/hot_hook/src/register.ts

@@ -0,0 +1,17 @@
+import { resolve } from 'node:path'
+import { hot } from './hot.js'
+import { readPackageUp } from 'read-package-up'
+
+const pkgJson = await readPackageUp()
+if (!pkgJson) {
+  throw new Error('Could not find package.json')
+}
+
+const { packageJson, path: packageJsonPath } = pkgJson
+const hotHookConfig = packageJson['hot-hook']
+
+await hot.init({
+  root: hotHookConfig?.root ? resolve(packageJsonPath, packageJson['hot-hook'].root) : undefined,
+  boundaries: packageJson['hot-hook']?.boundaries,
+  ignore: packageJson['hot-hook']?.ignore,
+})

packages/hot_hook/src/types.ts

@@ -21,7 +21,7 @@ export interface InitOptions {
   /**
    * Path to the root file of the application.
    */
-  root: string
+  root?: string
 
   /**
    * Files that will create an HMR boundary. This is equivalent of importing

packages/hot_hook/tests/register.spec.ts

@@ -0,0 +1,131 @@
+import { join } from 'node:path'
+import { pEvent } from 'p-event'
+import supertest from 'supertest'
+import { test } from '@japa/runner'
+import { setTimeout } from 'node:timers/promises'
+
+import { createHandlerFile, fakeInstall, runProcess } from './helpers.js'
+
+test.group('Register', () => {
+  test('Works fine with', async ({ fs }) => {
+    await fakeInstall(fs.basePath)
+
+    await fs.createJson('package.json', { type: 'module' })
+    await fs.create(
+      'server.js',
+      `import * as http from 'http'
+       import { join } from 'node:path'
+
+       const server = http.createServer(async (request, response) => {
+         const app = await import('./app.js', import.meta.hot?.boundary)
+         await app.default(request, response)
+       })
+
+       server.listen(3333, () => console.log('Server is running'))`
+    )
+
+    await createHandlerFile({ path: 'app.js', response: 'Hello World!' })
+
+    const server = runProcess('server.js', {
+      cwd: fs.basePath,
+      env: { NODE_DEBUG: 'hot-hook' },
+      nodeOptions: ['--import=hot-hook/register'],
+    })
+
+    await server.waitForOutput('Server is running')
+
+    await supertest('http://localhost:3333').get('/').expect(200).expect('Hello World!')
+
+    await setTimeout(100)
+    await createHandlerFile({ path: 'app.js', response: 'Hello World! Updated' })
+    await supertest('http://localhost:3333').get('/').expect(200).expect('Hello World! Updated')
+
+    await setTimeout(100)
+    await createHandlerFile({ path: 'app.js', response: 'Hello World! Updated new' })
+    await supertest('http://localhost:3333').get('/').expect(200).expect('Hello World! Updated new')
+  })
+
+  test('send full reload message', async ({ fs, assert }) => {
+    await fakeInstall(fs.basePath)
+
+    await fs.createJson('package.json', { type: 'module' })
+    await fs.create(
+      'server.js',
+      `import * as http from 'http'
+       import { join } from 'node:path'
+
+       const server = http.createServer(async (request, response) => {
+         const app = await import('./app.js')
+         await app.default(request, response)
+       })
+
+       server.listen(3333, () => console.log('Server is running'))`
+    )
+
+    await createHandlerFile({ path: 'app.js', response: 'Hello World!' })
+
+    const server = runProcess('server.js', {
+      cwd: fs.basePath,
+      env: { NODE_DEBUG: 'hot-hook' },
+      nodeOptions: ['--import=hot-hook/register'],
+    })
+
+    await server.waitForOutput('Server is running')
+
+    await supertest('http://localhost:3333').get('/').expect(200).expect('Hello World!')
+    await setTimeout(100)
+
+    await createHandlerFile({ path: 'app.js', response: 'Hello World! Updated' })
+    const result = await pEvent(
+      server.child,
+      'message',
+      (message: any) =>
+        message?.type === 'hot-hook:full-reload' && message.path === join(fs.basePath, 'app.js')
+    )
+    assert.isDefined(result)
+  })
+
+  test('Can define hardcoded boundaries from package json', async ({ fs }) => {
+    await fakeInstall(fs.basePath)
+
+    await fs.createJson('package.json', {
+      'type': 'module',
+      'hot-hook': {
+        boundaries: ['./app.js'],
+      },
+    })
+    await fs.create(
+      'server.js',
+      `import * as http from 'http'
+       import { join } from 'node:path'
+
+       const server = http.createServer(async (request, response) => {
+         const app = await import('./app.js')
+         await app.default(request, response)
+       })
+
+       server.listen(3333, () => console.log('Server is running'))
+      `
+    )
+
+    await createHandlerFile({ path: 'app.js', response: 'Hello World!' })
+
+    const server = runProcess('server.js', {
+      cwd: fs.basePath,
+      env: { NODE_DEBUG: 'hot-hook' },
+      nodeOptions: ['--import=hot-hook/register'],
+    })
+
+    await server.waitForOutput('Server is running')
+
+    await supertest('http://localhost:3333').get('/').expect(200).expect('Hello World!')
+
+    await setTimeout(100)
+    await createHandlerFile({ path: 'app.js', response: 'Hello World! Updated' })
+    await supertest('http://localhost:3333').get('/').expect(200).expect('Hello World! Updated')
+
+    await setTimeout(100)
+    await createHandlerFile({ path: 'app.js', response: 'Hello World! Updated new' })
+    await supertest('http://localhost:3333').get('/').expect(200).expect('Hello World! Updated new')
+  })
+})