Add require.resolve.

Also, hack the repl so that it works as expected there, too.

lib/repl.js

@@ -31,6 +31,8 @@ function cwdRequire (id) {
 Object.keys(require).forEach(function (k) {
   cwdRequire[k] = require[k];
 });
+// hack for require.resolve("./relative") to work properly.
+module.filename = process.cwd() + "/repl";
 
 function resetContext() {
   context = Script.createContext();

src/node.js

@@ -164,10 +164,8 @@ var module = (function () {
     };
   }
 
-  function findModulePath (id, dirs) {
-    process.assert(Array.isArray(dirs));
-
-    var nextLoc = traverser(id, id.charAt(0) === '/' ? [''] : dirs);
+  function findModulePath (request, paths) {
+    var nextLoc = traverser(request, request.charAt(0) === '/' ? [''] : paths);
 
     var fs = requireNative('fs');
 
@@ -181,7 +179,10 @@ var module = (function () {
 
 
   // sync - no i/o performed
-  function resolveModulePath(request, parent) {
+  function resolveModuleLookupPaths (request, parent) {
+
+    if (natives[request]) return [request, []];
+
     var start = request.substring(0, 2);
     if (start !== "./" && start !== "..") {
       return [request, modulePaths];
@@ -207,18 +208,33 @@ var module = (function () {
   function loadModule (request, parent) {
     debug("loadModule REQUEST  " + (request) + " parent: " + parent.id);
 
+    var resolved = resolveModuleFilename(request, parent);
+    var id = resolved[0];
+    var filename = resolved[1];
+
     // With natives id === request
     // We deal with these first
-    var cachedNative = internalModuleCache[request];
+    var cachedNative = internalModuleCache[id];
     if (cachedNative) {
       return cachedNative.exports;
     }
-    if (natives[request]) {
+    if (natives[id]) {
       debug('load native module ' + request);
-      return loadNative(request).exports;
+      return loadNative(id).exports;
     }
 
-    var resolvedModule = resolveModulePath(request, parent),
+    var cachedModule = moduleCache[filename];
+    if (cachedModule) return cachedModule.exports;
+
+    var module = new Module(id, parent);
+    moduleCache[filename] = module;
+    module.load(filename);
+    return module.exports;
+  };
+  
+  function resolveModuleFilename (request, parent) {
+    if (natives[request]) return [request, request];
+    var resolvedModule = resolveModuleLookupPaths(request, parent),
         id             = resolvedModule[0],
         paths          = resolvedModule[1];
 
@@ -228,15 +244,8 @@ var module = (function () {
     if (!filename) {
       throw new Error("Cannot find module '" + request + "'");
     }
-
-    var cachedModule = moduleCache[filename];
-    if (cachedModule) return cachedModule.exports;
-
-    var module = new Module(id, parent);
-    moduleCache[filename] = module;
-    module.load(filename);
-    return module.exports;
-  };
+    return [id, filename];
+  }
 
 
   Module.prototype.load = function (filename) {
@@ -262,6 +271,9 @@ var module = (function () {
       return loadModule(path, self);
     }
 
+    require.resolve = function (request) {
+      return resolveModuleFilename(request, self)[1];
+    }
     require.paths = modulePaths;
     require.main = process.mainModule;
     // Enable support to add extra extension types

test/simple/test-require-resolve.js

@@ -0,0 +1,14 @@
+var common = require("../common");
+var fixturesDir = common.fixturesDir;
+var assert = common.assert;
+var path = require("path");
+
+assert.equal(path.join(__dirname, "../fixtures/a.js"),
+             require.resolve("../fixtures/a"));
+assert.equal(path.join(fixturesDir, "a.js"),
+             require.resolve(path.join(fixturesDir, "a")));
+assert.equal(path.join(fixturesDir, "nested-index", "one", "index.js"),
+             require.resolve("../fixtures/nested-index/one"));
+assert.equal("path", require.resolve("path"));
+
+console.log("ok");