module: remove dead code

This removes a lot of code that has no functionality anymore. All Node.js internal code calls `_resolveLookupPaths` with two arguments. The code that validates `index.js` is not required at all as we check for these files anyway, so it's just redundant code that should be removed.

Author: BridgeAR

lib/internal/modules/cjs/helpers.js

@@ -23,7 +23,7 @@ function makeRequireFunction(mod) {
 
  function paths(request) {
  validateString(request, 'request');
- return Module._resolveLookupPaths(request, mod, true);
+ return Module._resolveLookupPaths(request, mod);
  }
 
  resolve.paths = paths;

lib/internal/modules/cjs/loader.js

@@ -63,16 +63,9 @@ let ModuleJob;
 let createDynamicModule;
 
 const {
- CHAR_UPPERCASE_A,
- CHAR_LOWERCASE_A,
- CHAR_UPPERCASE_Z,
- CHAR_LOWERCASE_Z,
  CHAR_FORWARD_SLASH,
  CHAR_BACKWARD_SLASH,
- CHAR_COLON,
- CHAR_UNDERSCORE,
- CHAR_0,
- CHAR_9,
+ CHAR_COLON
 } = require('internal/constants');
 
 const isWindows = process.platform === 'win32';
@@ -466,14 +459,10 @@ if (isWindows) {
  };
 }
 
-
-// 'index.' character codes
-const indexChars = [ 105, 110, 100, 101, 120, 46 ];
-const indexLen = indexChars.length;
-Module._resolveLookupPaths = function(request, parent, newReturn) {
+Module._resolveLookupPaths = function(request, parent) {
  if (NativeModule.canBeRequiredByUsers(request)) {
  debug('looking for %j in []', request);
- return (newReturn ? null : [request, []]);
+ return null;
  }
 
  // Check for node modules paths.
@@ -489,71 +478,24 @@ Module._resolveLookupPaths = function(request, parent, newReturn) {
  }
 
  debug('looking for %j in %j', request, paths);
- return (newReturn ? (paths.length > 0 ? paths : null) : [request, paths]);
+ return paths.length > 0 ? paths : null;
  }
 
  // With --eval, parent.id is not set and parent.filename is null.
  if (!parent || !parent.id || !parent.filename) {
  // Make require('./path/to/foo') work - normally the path is taken
  // from realpath(__filename) but with eval there is no filename
- var mainPaths = ['.'].concat(Module._nodeModulePaths('.'), modulePaths);
+ const mainPaths = ['.'].concat(Module._nodeModulePaths('.'), modulePaths);
 
  debug('looking for %j in %j', request, mainPaths);
- return (newReturn ? mainPaths : [request, mainPaths]);
- }
-
- // Is the parent an index module?
- // We can assume the parent has a valid extension,
- // as it already has been accepted as a module.
- const base = path.basename(parent.filename);
- var parentIdPath;
- if (base.length > indexLen) {
- var i = 0;
- for (; i < indexLen; ++i) {
- if (indexChars[i] !== base.charCodeAt(i))
- break;
- }
- if (i === indexLen) {
- // We matched 'index.', let's validate the rest
- for (; i < base.length; ++i) {
- const code = base.charCodeAt(i);
- if (code !== CHAR_UNDERSCORE &&
- (code < CHAR_0 || code > CHAR_9) &&
- (code < CHAR_UPPERCASE_A || code > CHAR_UPPERCASE_Z) &&
- (code < CHAR_LOWERCASE_A || code > CHAR_LOWERCASE_Z))
- break;
- }
- if (i === base.length) {
- // Is an index module
- parentIdPath = parent.id;
- } else {
- // Not an index module
- parentIdPath = path.dirname(parent.id);
- }
- } else {
- // Not an index module
- parentIdPath = path.dirname(parent.id);
- }
- } else {
- // Not an index module
- parentIdPath = path.dirname(parent.id);
- }
- var id = path.resolve(parentIdPath, request);
-
- // Make sure require('./path') and require('path') get distinct ids, even
- // when called from the toplevel js file
- if (parentIdPath === '.' &&
- id.indexOf('/') === -1 &&
- (!isWindows || id.indexOf('\\') === -1)) {
- id = './' + id;
+ return mainPaths;
  }
 
- debug('RELATIVE: requested: %s set ID to: %s from %s', request, id,
- parent.id);
+ debug('RELATIVE: requested: %s from parent.id %s', request, parent.id);
 
  const parentDir = [path.dirname(parent.filename)];
- debug('looking for %j in %j', id, parentDir);
- return (newReturn ? parentDir : [id, parentDir]);
+ debug('looking for %j', parentDir);
+ return parentDir;
 };
 
 // Check the cache for the requested file.
@@ -625,15 +567,15 @@ Module._resolveFilename = function(request, parent, isMain, options) {
  for (var i = 0; i < options.paths.length; i++) {
  const path = options.paths[i];
  fakeParent.paths = Module._nodeModulePaths(path);
- const lookupPaths = Module._resolveLookupPaths(request, fakeParent, true);
+ const lookupPaths = Module._resolveLookupPaths(request, fakeParent);
 
  for (var j = 0; j < lookupPaths.length; j++) {
  if (!paths.includes(lookupPaths[j]))
  paths.push(lookupPaths[j]);
  }
  }
  } else {
- paths = Module._resolveLookupPaths(request, parent, true);
+ paths = Module._resolveLookupPaths(request, parent);
  }
 
  // Look up the filename first, since that's the cache key.

lib/repl.js

@@ -855,8 +855,7 @@ REPLServer.prototype.createContext = function() {
  }
 
  const module = new CJSModule('<repl>');
- module.paths =
- CJSModule._resolveLookupPaths('<repl>', parentModule, true) || [];
+ module.paths = CJSModule._resolveLookupPaths('<repl>', parentModule) || [];
 
  Object.defineProperty(context, 'module', {
  configurable: true,

test/parallel/test-module-relative-lookup.js

@@ -10,12 +10,11 @@ function testFirstInPath(moduleName, isLocalModule) {
  assert.strictEqual :
  assert.notStrictEqual;
 
- const lookupResults = _module._resolveLookupPaths(moduleName);
+ let paths = _module._resolveLookupPaths(moduleName);
 
- let paths = lookupResults[1];
  assertFunction(paths[0], '.');
 
- paths = _module._resolveLookupPaths(moduleName, null, true);
+ paths = _module._resolveLookupPaths(moduleName, null);
  assertFunction(paths && paths[0], '.');
 }