lib: improve error message for MODULE_NOT_FOUND

Include the require stack in the reported error message. PR-URL: #25690 Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com> Reviewed-By: Colin Ihrig <cjihrig@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>
nodejs · Feb 13, 2019 · a02e3e2d5f1f96f3c408270d45935afdd5d1fffc · a02e3e2
1 parent 05cd1a0
commit a02e3e2d5f1f96f3c408270d45935afdd5d1fffc
diff --git a/lib/internal/modules/cjs/loader.js b/lib/internal/modules/cjs/loader.js
@@ -612,8 +612,12 @@ Module._resolveFilename = function(request, parent, isMain, options) {
      cursor = cursor.parent) {
      requireStack.push(cursor.filename || cursor.id);
    }
+  
+    let message = `Cannot find module '${request}'`;
+  
+    if (requireStack.length > 0) {
+  
+      message = message + '\nRequire stack:\n- ' + requireStack.join('\n- ');
+  
+    }
    // eslint-disable-next-line no-restricted-syntax
-  
-    var err = new Error(`Cannot find module '${request}'`);
+  
+    var err = new Error(message);
    err.code = 'MODULE_NOT_FOUND';
    err.requireStack = requireStack;
    throw err;

diff --git a/test/fixtures/require-resolve.js b/test/fixtures/require-resolve.js
@@ -15,21 +15,21 @@ assert.strictEqual(
 // Verify that existing paths are removed.
 assert.throws(() => {
  require.resolve('bar', { paths: [] })
-  
-}, /^Error: Cannot find module 'bar'$/);
+  
+}, /^Error: Cannot find module 'bar'/);
 // Verify that resolution path can be overwritten.
 {
  // three.js cannot be loaded from this file by default.
  assert.throws(() => {
    require.resolve('three')
-  
-  }, /^Error: Cannot find module 'three'$/);
+  
+  }, /^Error: Cannot find module 'three'/);
  // If the nested-index directory is provided as a resolve path, 'three'
  // cannot be found because nested-index is used as a starting point and not
  // a searched directory.
  assert.throws(() => {
    require.resolve('three', { paths: [nestedIndex] })
-  
-  }, /^Error: Cannot find module 'three'$/);
+  
+  }, /^Error: Cannot find module 'three'/);
  // Resolution from nested index directory also checks node_modules.
  assert.strictEqual(

diff --git a/test/parallel/test-internal-modules.js b/test/parallel/test-internal-modules.js
@@ -5,7 +5,7 @@ const assert = require('assert');
 assert.throws(function() {
  require('internal/freelist');
-  
-}, /^Error: Cannot find module 'internal\/freelist'$/);
+  
+}, /^Error: Cannot find module 'internal\/freelist'/);
 assert.strictEqual(
  require(fixtures.path('internal-modules')),

diff --git a/test/parallel/test-loaders-hidden-from-users.js b/test/parallel/test-loaders-hidden-from-users.js
@@ -9,7 +9,7 @@ common.expectsError(
    require('internal/bootstrap/loaders');
  }, {
    code: 'MODULE_NOT_FOUND',
-  
-    message: 'Cannot find module \'internal/bootstrap/loaders\''
+  
+    message: /Cannot find module 'internal\/bootstrap\/loaders'/
  }
 );
@@ -20,6 +20,6 @@ common.expectsError(
    require('owo');
  }, {
    code: 'MODULE_NOT_FOUND',
-  
-    message: 'Cannot find module \'owo\''
+  
+    message: /Cannot find module 'owo'/
  }
 );
diff --git a/test/parallel/test-module-loading-error.js b/test/parallel/test-module-loading-error.js
@@ -80,9 +80,10 @@ common.expectsError(
    message: 'The argument \'id\' must be a non-empty string. Received \'\''
  });
-  
-common.expectsError(
+  
+assert.throws(
  () => { require('../fixtures/packages/is-dir'); },
  {
    code: 'MODULE_NOT_FOUND',
-  
-    message: 'Cannot find module \'../fixtures/packages/is-dir\''
-  
-  });
+  
+    message: /Cannot find module '\.\.\/fixtures\/packages\/is-dir'/
+  
+  }
+  
+);
diff --git a/test/parallel/test-module-multi-extensions.js b/test/parallel/test-module-multi-extensions.js
@@ -35,7 +35,7 @@ fs.writeFileSync(dotfileWithExtension, 'console.log(__filename);', 'utf8');
  require(modulePath);
  assert.throws(
    () => require(`${modulePath}.foo`),
-  
-    new Error(`Cannot find module '${modulePath}.foo'`)
+  
+    (err) => err.message.startsWith(`Cannot find module '${modulePath}.foo'`)
  );
  require(`${modulePath}.foo.bar`);
  delete require.cache[file];
@@ -47,7 +47,7 @@ fs.writeFileSync(dotfileWithExtension, 'console.log(__filename);', 'utf8');
  const modulePath = path.join(tmpdir.path, 'test-extensions');
  assert.throws(
    () => require(modulePath),
-  
-    new Error(`Cannot find module '${modulePath}'`)
+  
+    (err) => err.message.startsWith(`Cannot find module '${modulePath}'`)
  );
  delete require.cache[file];
  Module._pathCache = Object.create(null);
@@ -69,7 +69,7 @@ fs.writeFileSync(dotfileWithExtension, 'console.log(__filename);', 'utf8');
  const modulePath = path.join(tmpdir.path, 'test-extensions.foo');
  assert.throws(
    () => require(modulePath),
-  
-    new Error(`Cannot find module '${modulePath}'`)
+  
+    (err) => err.message.startsWith(`Cannot find module '${modulePath}'`)
  );
  delete require.extensions['.foo.bar'];
  Module._pathCache = Object.create(null);

diff --git a/test/parallel/test-repl.js b/test/parallel/test-repl.js
@@ -534,6 +534,8 @@ const errorTests = [
    expect: [
      'Thrown:',
      /^{ Error: Cannot find module 'internal\/repl'/,
+  
+      /^Require stack:/,
+  
+      /^- <repl>/,
      /^    at .*/,
      /^    at .*/,
      /^    at .*/,

diff --git a/test/sequential/test-module-loading.js b/test/sequential/test-module-loading.js
@@ -131,7 +131,7 @@ require('../fixtures/node_modules/foo');
  assert.ok(my_path.path_func instanceof Function);
  // this one does not exist and should throw
  assert.throws(function() { require('./utils'); },
-  
-                /^Error: Cannot find module '\.\/utils'$/);
+  
+                /^Error: Cannot find module '\.\/utils'/);
 }
 let errorThrown = false;
@@ -170,12 +170,13 @@ assert.strictEqual(require('../fixtures/registerExt2').custom, 'passed');
 assert.strictEqual(require('../fixtures/foo').foo, 'ok');
 // Should not attempt to load a directory
-  
-try {
-  
-  tmpdir.refresh();
-  
-  require(tmpdir.path);
-  
-} catch (err) {
-  
-  assert.strictEqual(err.message, `Cannot find module '${tmpdir.path}'`);
-  
-}
+  
+assert.throws(
+  
+  () => {
+  
+    tmpdir.refresh();
+  
+    require(tmpdir.path);
+  
+  },
+  
+  (err) => err.message.startsWith(`Cannot find module '${tmpdir.path}`)
+  
+);
 {
  // Check load order is as expected