From 6dd7f53588d03688b7ade05dbc5e0c314beb962e Mon Sep 17 00:00:00 2001
From: Anthony Fu <anthonyfu117@hotmail.com>
Date: Tue, 29 Mar 2022 17:35:57 +0800
Subject: [PATCH] feat(vite-node): support debug flag to emit additional info

---
 packages/vite-node/src/client.ts | 47 +++++++++++++++++++++++++-------
 packages/vite-node/src/types.ts  |  1 +
 2 files changed, 38 insertions(+), 10 deletions(-)

diff --git a/packages/vite-node/src/client.ts b/packages/vite-node/src/client.ts
index 29cb4288a5ab..6cf320995350 100644
--- a/packages/vite-node/src/client.ts
+++ b/packages/vite-node/src/client.ts
@@ -51,6 +51,8 @@ export class ModuleCacheMap extends Map<string, ModuleCache> {
 export class ViteNodeRunner {
   root: string
 
+  debug: boolean
+
   /**
    * Holds the cache of modules
    * Keys of the map are filepaths, or plain package names
@@ -58,8 +60,9 @@ export class ViteNodeRunner {
   moduleCache: ModuleCacheMap
 
   constructor(public options: ViteNodeRunnerOptions) {
-    this.root = options.root || process.cwd()
-    this.moduleCache = options.moduleCache || new ModuleCacheMap()
+    this.root = options.root ?? process.cwd()
+    this.moduleCache = options.moduleCache ?? new ModuleCacheMap()
+    this.debug = options.debug ?? (typeof process !== 'undefined' ? !!process.env.VITE_NODE_DEBUG : false)
   }
 
   async executeFile(file: string) {
@@ -85,9 +88,13 @@ export class ViteNodeRunner {
   }
 
   /** @internal */
-  async directRequest(id: string, fsPath: string, callstack: string[]) {
-    callstack = [...callstack, normalizeModuleId(id)]
+  async directRequest(id: string, fsPath: string, _callstack: string[]) {
+    const callstack = [..._callstack, normalizeModuleId(id)]
     const request = async(dep: string) => {
+      const getStack = () => {
+        return `stack:\n${[...callstack, dep].reverse().map(p => `- ${p}`).join('\n')}`
+      }
+
       // probably means it was passed as variable
       // and wasn't transformed by Vite
       if (this.options.resolveId && this.shouldResolveId(dep)) {
@@ -95,13 +102,27 @@ export class ViteNodeRunner {
         dep = resolvedDep?.id?.replace(this.root, '') || dep
       }
 
-      if (callstack.includes(normalizeModuleId(dep))) {
-        const depExports = this.moduleCache.get(dep)?.exports
-        if (depExports)
-          return depExports
-        throw new Error(`[vite-node] Circular dependency detected\nStack:\n${[...callstack, dep].reverse().map(p => `- ${p}`).join('\n')}`)
+      let debugTimer: any
+      if (this.debug)
+        debugTimer = setTimeout(() => this.debugLog(() => `module ${dep} takes over 2s to load.\n${getStack()}`), 2000)
+
+      try {
+        if (callstack.includes(normalizeModuleId(dep))) {
+          this.debugLog(() => `circular dependency, ${getStack()}`)
+          const depExports = this.moduleCache.get(dep)?.exports
+          if (depExports)
+            return depExports
+          throw new Error(`[vite-node] Failed to resolve circular dependency, ${getStack()}`)
+        }
+
+        const mod = await this.cachedRequest(dep, callstack)
+
+        return mod
+      }
+      finally {
+        if (debugTimer)
+          clearTimeout(debugTimer)
       }
-      return this.cachedRequest(dep, callstack)
     }
 
     const requestStubs = this.options.requestStubs || DEFAULT_REQUEST_STUBS
@@ -212,6 +233,12 @@ export class ViteNodeRunner {
   hasNestedDefault(target: any) {
     return '__esModule' in target && target.__esModule && 'default' in target.default
   }
+
+  private debugLog(msg: () => string) {
+    if (this.debug)
+      // eslint-disable-next-line no-console
+      console.log(`[vite-node] ${msg()}`)
+  }
 }
 
 function proxyMethod(name: 'get' | 'set' | 'has' | 'deleteProperty', tryDefault: boolean) {
diff --git a/packages/vite-node/src/types.ts b/packages/vite-node/src/types.ts
index 92a15e6c2d8c..06666b4c2cb6 100644
--- a/packages/vite-node/src/types.ts
+++ b/packages/vite-node/src/types.ts
@@ -47,6 +47,7 @@ export interface ViteNodeRunnerOptions {
   moduleCache?: ModuleCacheMap
   interopDefault?: boolean
   requestStubs?: Record<string, any>
+  debug?: boolean
 }
 
 export interface ViteNodeResolveId {