Feat/plugin develop (medusajs#10926)

Fixes: FRMW-2865

In this PR we add support for developing a plugin in watch mode. During the file change, we re-compile the source code (incrementally), publishes the package, and updates the installations of the plugin. 

We are using `yalc` under the hood and it must be installed as a dev dependency in the plugin project and the main Medusa app.

.changeset/forty-lamps-fly.md

@@ -0,0 +1,7 @@
+---
+"@medusajs/medusa": patch
+"@medusajs/framework": patch
+"@medusajs/cli": patch
+---
+
+Feat/plugin develop

packages/cli/medusa-cli/src/create-cli.ts

@@ -254,6 +254,18 @@ function buildLocalCommands(cli, isLocalProject) {
         })
       ),
     })
+    .command({
+      command: "plugin:develop",
+      desc: "Start plugin development process in watch mode. Changes will be re-published to the local packages registry",
+      builder: (builder) => {},
+      handler: handlerP(
+        getCommandHandler("plugin/develop", (args, cmd) => {
+          process.env.NODE_ENV = process.env.NODE_ENV || `development`
+          cmd(args)
+          return new Promise(() => {})
+        })
+      ),
+    })
     .command({
       command: `telemetry`,
       describe: `Enable or disable collection of anonymous usage data.`,
@@ -310,7 +322,7 @@ function buildLocalCommands(cli, isLocalProject) {
           // Return an empty promise to prevent handlerP from exiting early.
           // The development server shouldn't ever exit until the user directly
           // kills it so this is fine.
-          return new Promise((resolve) => {})
+          return new Promise(() => {})
         })
       ),
     })

packages/core/framework/src/build-tools/compiler.ts

@@ -23,15 +23,26 @@ import type { AdminOptions, ConfigModule, Logger } from "@medusajs/types"
 export class Compiler {
   #logger: Logger
   #projectRoot: string
+  #tsConfigPath: string
   #adminSourceFolder: string
+  #pluginsDistFolder: string
+  #backendIgnoreFiles: string[]
   #adminOnlyDistFolder: string
   #tsCompiler?: typeof tsStatic
 
   constructor(projectRoot: string, logger: Logger) {
     this.#projectRoot = projectRoot
     this.#logger = logger
+    this.#tsConfigPath = path.join(this.#projectRoot, "tsconfig.json")
     this.#adminSourceFolder = path.join(this.#projectRoot, "src/admin")
     this.#adminOnlyDistFolder = path.join(this.#projectRoot, ".medusa/admin")
+    this.#pluginsDistFolder = path.join(this.#projectRoot, ".medusa/server")
+    this.#backendIgnoreFiles = [
+      "integration-tests",
+      "test",
+      "unit-tests",
+      "src/admin",
+    ]
   }
 
   /**
@@ -141,6 +152,20 @@ export class Compiler {
     return { configFilePath, configModule }
   }
 
+  /**
+   * Prints typescript diagnostic messages
+   */
+  #printDiagnostics(ts: typeof tsStatic, diagnostics: tsStatic.Diagnostic[]) {
+    if (diagnostics.length) {
+      console.error(
+        ts.formatDiagnosticsWithColorAndContext(
+          diagnostics,
+          ts.createCompilerHost({})
+        )
+      )
+    }
+  }
+
   /**
    * Given a tsconfig file, this method will write the compiled
    * output to the specified destination
@@ -177,14 +202,7 @@ export class Compiler {
     /**
      * Log errors (if any)
      */
-    if (diagnostics.length) {
-      console.error(
-        ts.formatDiagnosticsWithColorAndContext(
-          diagnostics,
-          ts.createCompilerHost({})
-        )
-      )
-    }
+    this.#printDiagnostics(ts, diagnostics)
 
     return { emitResult, diagnostics }
   }
@@ -198,7 +216,7 @@ export class Compiler {
     let tsConfigErrors: tsStatic.Diagnostic[] = []
 
     const tsConfig = ts.getParsedCommandLineOfConfigFile(
-      path.join(this.#projectRoot, "tsconfig.json"),
+      this.#tsConfigPath,
       {
         inlineSourceMap: true,
         excludes: [],
@@ -223,18 +241,17 @@ export class Compiler {
     /**
      * Display all config errors using the diagnostics reporter
      */
+    this.#printDiagnostics(ts, tsConfigErrors)
+
+    /**
+     * Return undefined when there are errors in parsing the config
+     * file
+     */
     if (tsConfigErrors.length) {
-      const compilerHost = ts.createCompilerHost({})
-      this.#logger.error(
-        ts.formatDiagnosticsWithColorAndContext(tsConfigErrors, compilerHost)
-      )
       return
     }
 
-    /**
-     * If there are no errors, the `tsConfig` object will always exist.
-     */
-    return tsConfig!
+    return tsConfig
   }
 
   /**
@@ -262,7 +279,7 @@ export class Compiler {
      */
     const { emitResult, diagnostics } = await this.#emitBuildOutput(
       tsConfig,
-      ["integration-tests", "test", "unit-tests", "src/admin"],
+      this.#backendIgnoreFiles,
       dist
     )
 
@@ -365,9 +382,61 @@ export class Compiler {
     }
   }
 
+  // @todo
+  buildPluginBackend() {}
+
   /**
-   * @todo. To be implemented
+   * Compiles the backend source code of a plugin project in watch
+   * mode. Type-checking is disabled to keep compilation fast.
+   *
+   * The "onFileChange" argument can be used to get notified when
+   * a file has changed.
    */
-  buildPluginBackend() {}
-  developPluginBacked() {}
+  async developPluginBackend(onFileChange?: () => void) {
+    const ts = await this.#loadTSCompiler()
+
+    /**
+     * Format host is needed to print diagnostic messages
+     */
+    const formatHost: tsStatic.FormatDiagnosticsHost = {
+      getCanonicalFileName: (path) => path,
+      getCurrentDirectory: ts.sys.getCurrentDirectory,
+      getNewLine: () => ts.sys.newLine,
+    }
+
+    /**
+     * Creating a watcher compiler host to watch files and recompile
+     * them as they are changed
+     */
+    const host = ts.createWatchCompilerHost(
+      this.#tsConfigPath,
+      {
+        outDir: this.#pluginsDistFolder,
+        noCheck: true,
+      },
+      ts.sys,
+      ts.createEmitAndSemanticDiagnosticsBuilderProgram,
+      (diagnostic) => this.#printDiagnostics(ts, [diagnostic]),
+      (diagnostic) => {
+        if (typeof diagnostic.messageText === "string") {
+          this.#logger.info(diagnostic.messageText)
+        } else {
+          this.#logger.info(
+            ts.formatDiagnosticsWithColorAndContext([diagnostic], formatHost)
+          )
+        }
+      },
+      {
+        excludeDirectories: this.#backendIgnoreFiles,
+      }
+    )
+
+    const origPostProgramCreate = host.afterProgramCreate
+    host.afterProgramCreate = (program) => {
+      origPostProgramCreate!(program)
+      onFileChange?.()
+    }
+
+    ts.createWatchProgram(host)
+  }
 }

packages/medusa/package.json

@@ -57,7 +57,8 @@
     "@types/multer": "^1.4.7",
     "jest": "^29.7.0",
     "rimraf": "^5.0.1",
-    "typescript": "^5.6.2"
+    "typescript": "^5.6.2",
+    "yalc": "1.0.0-pre.53"
   },
   "dependencies": {
     "@inquirer/checkbox": "^2.3.11",
@@ -130,7 +131,13 @@
     "@mikro-orm/knex": "5.9.7",
     "@mikro-orm/migrations": "5.9.7",
     "@mikro-orm/postgresql": "5.9.7",
-    "awilix": "^8.0.1"
+    "awilix": "^8.0.1",
+    "yalc": "1.0.0-pre.53"
+  },
+  "peerDependenciesMeta": {
+    "yalc": {
+      "optional": true
+    }
   },
   "gitHead": "cd1f5afa5aa8c0b15ea957008ee19f1d695cbd2e"
 }

packages/medusa/src/commands/plugin/develop.ts

@@ -0,0 +1,19 @@
+import * as yalc from "yalc"
+import { logger } from "@medusajs/framework/logger"
+import { Compiler } from "@medusajs/framework/build-tools"
+
+export default async function developPlugin({
+  directory,
+}: {
+  directory: string
+}) {
+  const compiler = new Compiler(directory, logger)
+  await compiler.developPluginBackend(async () => {
+    await yalc.publishPackage({
+      push: true,
+      workingDir: directory,
+      changed: true,
+      replace: true,
+    })
+  })
+}

yarn.lock

@@ -6132,6 +6132,7 @@ __metadata:
     slugify: ^1.6.6
     typescript: ^5.6.2
     uuid: ^9.0.0
+    yalc: 1.0.0-pre.53
     zod: 3.22.4
   peerDependencies:
     "@medusajs/framework": ^2.0.0
@@ -6140,6 +6141,10 @@ __metadata:
     "@mikro-orm/migrations": 5.9.7
     "@mikro-orm/postgresql": 5.9.7
     awilix: ^8.0.1
+    yalc: 1.0.0-pre.53
+  peerDependenciesMeta:
+    yalc:
+      optional: true
   languageName: unknown
   linkType: soft
 
@@ -20760,7 +20765,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"fs-extra@npm:8.1.0, fs-extra@npm:^8.1, fs-extra@npm:^8.1.0":
+"fs-extra@npm:8.1.0, fs-extra@npm:^8.0.1, fs-extra@npm:^8.1, fs-extra@npm:^8.1.0":
   version: 8.1.0
   resolution: "fs-extra@npm:8.1.0"
   dependencies:
@@ -21797,13 +21802,29 @@ __metadata:
   languageName: node
   linkType: hard
 
+"ignore-walk@npm:^3.0.3":
+  version: 3.0.4
+  resolution: "ignore-walk@npm:3.0.4"
+  dependencies:
+    minimatch: ^3.0.4
+  checksum: 690372b433887796fa3badd25babab7daf60a1882259dcc130ec78eea79745c2416322e10d1a96b367071204471c532647d20b11cd7ab70bd9b49879e461f956
+  languageName: node
+  linkType: hard
+
 "ignore@npm:^4.0.6":
   version: 4.0.6
   resolution: "ignore@npm:4.0.6"
   checksum: 836ee7dc7fd9436096e2dba429359dbb9fa0e33d309e2b2d81692f375f6ca82024fc00567f798613d50c6b989e9cd2ad2b065acf116325cde177f02c86b7d4e0
   languageName: node
   linkType: hard
 
+"ignore@npm:^5.0.4":
+  version: 5.3.2
+  resolution: "ignore@npm:5.3.2"
+  checksum: f9f652c957983634ded1e7f02da3b559a0d4cc210fca3792cb67f1b153623c9c42efdc1c4121af171e295444459fc4a9201101fb041b1104a3c000bccb188337
+  languageName: node
+  linkType: hard
+
 "ignore@npm:^5.2.0, ignore@npm:^5.2.4":
   version: 5.3.1
   resolution: "ignore@npm:5.3.1"
@@ -21936,6 +21957,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"ini@npm:^2.0.0":
+  version: 2.0.0
+  resolution: "ini@npm:2.0.0"
+  checksum: 2e0c8f386369139029da87819438b20a1ff3fe58372d93fb1a86e9d9344125ace3a806b8ec4eb160a46e64cbc422fe68251869441676af49b7fc441af2389c25
+  languageName: node
+  linkType: hard
+
 "inquirer@npm:^8.0.0":
   version: 8.2.6
   resolution: "inquirer@npm:8.2.6"
@@ -25831,6 +25859,36 @@ __metadata:
   languageName: node
   linkType: hard
 
+"npm-bundled@npm:^1.1.1":
+  version: 1.1.2
+  resolution: "npm-bundled@npm:1.1.2"
+  dependencies:
+    npm-normalize-package-bin: ^1.0.1
+  checksum: 3f2337789afc8cb608a0dd71cefe459531053d48a5497db14b07b985c4cab15afcae88600db9f92eae072c89b982eeeec8e4463e1d77bc03a7e90f5dacf29769
+  languageName: node
+  linkType: hard
+
+"npm-normalize-package-bin@npm:^1.0.1":
+  version: 1.0.1
+  resolution: "npm-normalize-package-bin@npm:1.0.1"
+  checksum: b0c8c05fe419a122e0ff970ccbe7874ae24b4b4b08941a24d18097fe6e1f4b93e3f6abfb5512f9c5488827a5592f2fb3ce2431c41d338802aed24b9a0c160551
+  languageName: node
+  linkType: hard
+
+"npm-packlist@npm:^2.1.5":
+  version: 2.2.2
+  resolution: "npm-packlist@npm:2.2.2"
+  dependencies:
+    glob: ^7.1.6
+    ignore-walk: ^3.0.3
+    npm-bundled: ^1.1.1
+    npm-normalize-package-bin: ^1.0.1
+  bin:
+    npm-packlist: bin/index.js
+  checksum: cf0b1350bfa2e4bdef5e283365fb54811bd095f4b6c8e5f1352a12a155f9aafbd22776b5a79fea7c5e952fab2e72c40f54cea2e139d7d705cfc6f6f955f1aa48
+  languageName: node
+  linkType: hard
+
 "npm-run-path@npm:^2.0.0":
   version: 2.0.2
   resolution: "npm-run-path@npm:2.0.2"
@@ -33799,6 +33857,24 @@ __metadata:
   languageName: node
   linkType: hard
 
+"yalc@npm:1.0.0-pre.53":
+  version: 1.0.0-pre.53
+  resolution: "yalc@npm:1.0.0-pre.53"
+  dependencies:
+    chalk: ^4.1.0
+    detect-indent: ^6.0.0
+    fs-extra: ^8.0.1
+    glob: ^7.1.4
+    ignore: ^5.0.4
+    ini: ^2.0.0
+    npm-packlist: ^2.1.5
+    yargs: ^16.1.1
+  bin:
+    yalc: src/yalc.js
+  checksum: 630f65b00740da6d568d46748a40e2bf2c872cf9babe7c319642a5b6db2dcd0a5d4a34e249d20099709e3ba09bb7e9b34ff78af5cd54c690668e094e156551c9
+  languageName: node
+  linkType: hard
+
 "yallist@npm:^2.1.2":
   version: 2.1.2
   resolution: "yallist@npm:2.1.2"
@@ -33916,7 +33992,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"yargs@npm:^16.1.0":
+"yargs@npm:^16.1.0, yargs@npm:^16.1.1":
   version: 16.2.0
   resolution: "yargs@npm:16.2.0"
   dependencies: