Implement `require.cache` (#3045)

Co-authored-by: Jarred Sumner <709451+Jarred-Sumner@users.noreply.github.com>

3 files changed, 112 insertions, 0 deletions

diff --git a/src/bun.js/builtins/WebCoreJSBuiltins.cpp b/src/bun.js/builtins/WebCoreJSBuiltins.cpp
index 898765f86..ab93a17ea 100644
--- a/src/bun.js/builtins/WebCoreJSBuiltins.cpp
+++ b/src/bun.js/builtins/WebCoreJSBuiltins.cpp
@@ -2208,6 +2208,14 @@ const int s_importMetaObjectInternalRequireCodeLength = 569;
 static const JSC::Intrinsic s_importMetaObjectInternalRequireCodeIntrinsic = JSC::NoIntrinsic;
 const char* const s_importMetaObjectInternalRequireCode = "(function (n){\"use strict\";var _=@requireMap.@get(n);const i=n.substring(n.length-5);if(_){if(i===\".node\")return _.exports;return _}if(i===\".json\"){var S=globalThis[Symbol.for(\"_fs\")]||=@Bun.fs(),F=JSON.parse(S.readFileSync(n,\"utf8\"));return @requireMap.@set(n,F),F}else if(i===\".node\"){var b={exports:{}};return process.dlopen(b,n),@requireMap.@set(n,b),b.exports}else if(i===\".toml\"){var S=globalThis[Symbol.for(\"_fs\")]||=@Bun.fs(),F=@Bun.TOML.parse(S.readFileSync(n,\"utf8\"));return @requireMap.@set(n,F),F}else{var F=@requireESM(n);return @requireMap.@set(n,F),F}})\n";
 
+// createRequireCache
+const JSC::ConstructAbility s_importMetaObjectCreateRequireCacheCodeConstructAbility = JSC::ConstructAbility::CannotConstruct;
+const JSC::ConstructorKind s_importMetaObjectCreateRequireCacheCodeConstructorKind = JSC::ConstructorKind::None;
+const JSC::ImplementationVisibility s_importMetaObjectCreateRequireCacheCodeImplementationVisibility = JSC::ImplementationVisibility::Public;
+const int s_importMetaObjectCreateRequireCacheCodeLength = 888;
+static const JSC::Intrinsic s_importMetaObjectCreateRequireCacheCodeIntrinsic = JSC::NoIntrinsic;
+const char* const s_importMetaObjectCreateRequireCacheCode = "(function (){\"use strict\";class r{id;parent;filename;children=[];paths=[];constructor(_){this.id=_;const c=_.lastIndexOf(\"/\");if(c!==-1&&_.length>c+1)this.filename=_.substring(c+1);else this.filename=_}get loaded(){return!0}require(_){return @internalRequire(@resolveSync(_,this.id))}get exports(){return @requireMap.@get(this.id)\?\?{}}set exports(_){@requireMap.@set(this.id,_)}}var w=new Map;return new Proxy({},{get(_,c){if(@requireMap.@get(c)){var b=w.@get(c);if(!b)b=new r(c),w.@set(c,b);return b}},set(_,c,t){if(!w.@has(c))w.@set(c,new r(c));return @requireMap.@set(c,t\?.exports),!0},has(_,c){return @requireMap.@has(c)},deleteProperty(_,c){return w.@delete(c),@requireMap.@delete(c),@Loader.registry.@delete(c)},ownKeys(_){return[...@requireMap.@keys()]},getPrototypeOf(_){return null},getOwnPropertyDescriptor(_,c){if(@requireMap.@has(c))return{configurable:!0,enumerable:!0}}})})\n";
+
 // require
 const JSC::ConstructAbility s_importMetaObjectRequireCodeConstructAbility = JSC::ConstructAbility::CannotConstruct;
 const JSC::ConstructorKind s_importMetaObjectRequireCodeConstructorKind = JSC::ConstructorKind::None;
diff --git a/src/bun.js/builtins/WebCoreJSBuiltins.h b/src/bun.js/builtins/WebCoreJSBuiltins.h
index 2f1fd3816..3414ed847 100644
--- a/src/bun.js/builtins/WebCoreJSBuiltins.h
+++ b/src/bun.js/builtins/WebCoreJSBuiltins.h
@@ -3964,6 +3964,14 @@ extern const JSC::ConstructAbility s_importMetaObjectInternalRequireCodeConstruc
 extern const JSC::ConstructorKind s_importMetaObjectInternalRequireCodeConstructorKind;
 extern const JSC::ImplementationVisibility s_importMetaObjectInternalRequireCodeImplementationVisibility;
 
+// createRequireCache
+#define WEBCORE_BUILTIN_IMPORTMETAOBJECT_CREATEREQUIRECACHE 1
+extern const char* const s_importMetaObjectCreateRequireCacheCode;
+extern const int s_importMetaObjectCreateRequireCacheCodeLength;
+extern const JSC::ConstructAbility s_importMetaObjectCreateRequireCacheCodeConstructAbility;
+extern const JSC::ConstructorKind s_importMetaObjectCreateRequireCacheCodeConstructorKind;
+extern const JSC::ImplementationVisibility s_importMetaObjectCreateRequireCacheCodeImplementationVisibility;
+
 // require
 #define WEBCORE_BUILTIN_IMPORTMETAOBJECT_REQUIRE 1
 extern const char* const s_importMetaObjectRequireCode;
@@ -3984,6 +3992,7 @@ extern const JSC::ImplementationVisibility s_importMetaObjectMainCodeImplementat
     macro(loadCJS2ESM, importMetaObjectLoadCJS2ESM, 1) \
     macro(requireESM, importMetaObjectRequireESM, 1) \
     macro(internalRequire, importMetaObjectInternalRequire, 1) \
+    macro(createRequireCache, importMetaObjectCreateRequireCache, 0) \
     macro(require, importMetaObjectRequire, 1) \
     macro(main, importMetaObjectMain, 0) \
 
@@ -3991,6 +4000,7 @@ extern const JSC::ImplementationVisibility s_importMetaObjectMainCodeImplementat
     macro(importMetaObjectLoadCJS2ESMCode, loadCJS2ESM, ASCIILiteral(), s_importMetaObjectLoadCJS2ESMCodeLength) \
     macro(importMetaObjectRequireESMCode, requireESM, ASCIILiteral(), s_importMetaObjectRequireESMCodeLength) \
     macro(importMetaObjectInternalRequireCode, internalRequire, ASCIILiteral(), s_importMetaObjectInternalRequireCodeLength) \
+    macro(importMetaObjectCreateRequireCacheCode, createRequireCache, ASCIILiteral(), s_importMetaObjectCreateRequireCacheCodeLength) \
     macro(importMetaObjectRequireCode, require, ASCIILiteral(), s_importMetaObjectRequireCodeLength) \
     macro(importMetaObjectMainCode, main, "get main"_s, s_importMetaObjectMainCodeLength) \
 
@@ -3998,6 +4008,7 @@ extern const JSC::ImplementationVisibility s_importMetaObjectMainCodeImplementat
     macro(loadCJS2ESM) \
     macro(requireESM) \
     macro(internalRequire) \
+    macro(createRequireCache) \
     macro(require) \
     macro(main) \
 
diff --git a/src/bun.js/builtins/ts/ImportMetaObject.ts b/src/bun.js/builtins/ts/ImportMetaObject.ts
index 6c66075c6..9ce53c192 100644
--- a/src/bun.js/builtins/ts/ImportMetaObject.ts
+++ b/src/bun.js/builtins/ts/ImportMetaObject.ts
@@ -135,6 +135,99 @@ export function internalRequire(this: ImportMetaObject, resolved) {
   }
 }
 
+export function createRequireCache() {
+  class Module {
+    id;
+    parent;
+    filename;
+    children = [];
+    paths = [];
+
+    constructor(filename) {
+      this.id = filename;
+      // TODO: windows
+      const lastSlash = filename.lastIndexOf("/");
+      if (lastSlash !== -1 && filename.length > lastSlash + 1) {
+        this.filename = filename.substring(lastSlash + 1);
+      } else {
+        this.filename = filename;
+      }
+    }
+
+    get loaded() {
+      return true;
+    }
+
+    require(path) {
+      return $internalRequire($resolveSync(path, this.id));
+    }
+
+    get exports() {
+      return $requireMap.$get(this.id) ?? {};
+    }
+
+    set exports(value) {
+      $requireMap.$set(this.id, value);
+    }
+  }
+
+  var moduleMap = new Map();
+
+  return new Proxy(
+    {},
+    {
+      get(target, key: string) {
+        const entry = $requireMap.$get(key);
+        if (entry) {
+          var mod = moduleMap.$get(key);
+          if (!mod) {
+            mod = new Module(key);
+            moduleMap.$set(key, mod);
+          }
+          return mod;
+        }
+      },
+      set(target, key: string, value) {
+        if (!moduleMap.$has(key)) {
+          moduleMap.$set(key, new Module(key));
+        }
+
+        $requireMap.$set(key, value?.exports);
+
+        return true;
+      },
+
+      has(target, key: string) {
+        return $requireMap.$has(key);
+      },
+
+      deleteProperty(target, key: string) {
+        moduleMap.$delete(key);
+        $requireMap.$delete(key);
+        return Loader.registry.$delete(key);
+      },
+
+      ownKeys(target) {
+        return [...$requireMap.$keys()];
+      },
+
+      // In Node, require.cache has a null prototype
+      getPrototypeOf(target) {
+        return null;
+      },
+
+      getOwnPropertyDescriptor(target, key: string) {
+        if ($requireMap.$has(key)) {
+          return {
+            configurable: true,
+            enumerable: true,
+          };
+        }
+      },
+    },
+  );
+}
+
 $sloppy;
 export function require(this: ImportMetaObject, name) {
   var from = this?.path ?? arguments.callee.path;