RequireJS Module Support

Looks up modules and identifiers in CJS/AMD/ES projects using RequireJS.

• Go To Definition and Find All References for imported identifiers and string literals with module names.
• Autocomplete module names when typing.
• Show module paths when hovering above module names.
• Rename imported and exported symbols.
• Support module formats CJS, AMD, UMD and ES.
• Support modern JavaScript (ES2021).

This project started by enhancing the extension Require Module Support, but was rewritten to use parsing and AST traversal instead of regexp string matching, when the original approach started making further improvements difficult. It might behave differently than the original extension, but it should follow the language more correctly.

Installation

Look for RequireJS Module Support in the Visual Studio Marketplace, Open VSX Registry, or install the extension by the command line, if you have the VS Code or VS Codium binary in PATH:

code --install-extension prantlf.vscode-requirejs
vscodium --install-extension prantlf.vscode-requirejs

If you used the extension Require Module Support, uninstall it or disable it to prevent conflicts.

Navigation

You can navigate to the source file from locations marked with the caret (^):

// main
require('moduleA').foo()
           ^       ^

// moduleC
define(['moduleA', 'moduleB'], function(a, b) {
           ^           ^                ^  ^
  var foo = a
       ^    ^
  var bar = new b()
       ^        ^
  foo.baz()
   ^  ^
  bar.prop
   ^    ^
})

// moduleC ESM
import a from 'moduleA'
       ^          ^
import b from 'moduleB'
       ^          ^
const foo = a
       ^    ^
const bar = b
       ^    ^
foo.baz()
 ^   ^
bar.prop
 ^   ^

// moduleA
define(() => {
  return {
    foo: function() { ... },
    bar: function() { ... },
    baz: function() { ... }
  }
})

// moduleB
export default {
  prop: 6
}

Settings

The following properties can be set in settings.json to override the default values. The names from the table below have to be prefixed with requireModuleSupport., which is omitted in the table to save space. Paths in property values should be relative to the workspace root. See also the project examples.

Name	Type	Default	Description
enableDefinitionProvider	boolean	true	Enables cross-module symbol lookup in the "Go to Definition" command.
enableReferenceProvider	boolean	true	Enables cross-module symbol lookup in the "Find All References" command.
enableCompletionItemProvider	boolean	true	Enables selecting from the module directory content when typing "/" inside a string with a module path.
enableHoverProvider	boolean	true	Enables displaying the file-system path, which the module path resolves to, when hovering with the mouse cursor above a string with a module path.
enableRenameProvider	boolean	true	Enables cross-module symbol lookup in the "Rename Symbol" command.
showGoToDefinitionModuleCommand	boolean	true	Shows the "Go to Definition Module" command in context menus.
showRenameExportedSymbolCommand	boolean	true	Shows the "Rename Exported Symbol" command in context menus.
configFile	string	``	Path of the RequireJS configuration file relative to workspace root
enableCjsModules	boolean	false	Parse source files as pure CommonJS modules
enableJsxModules	boolean	false	Enable support for the JSX language extension
enableEsModules	boolean	false	Enable detection of ES modules in addition to AMD or CJS modules
moduleCacheSize	integer	10000	Maximum count of parsed modules and their dependencies kept in memory as cache to improve performance
dynamicModuleCacheSize	boolean	true	Make cache sizes depend on the count of JavaScript modules in the project
dynamicModuleCacheSizeExtra	integer	10	How many percent of the JavaScript module count should be reserved not to exhaust the cache so quickly
includeModulePattern	string	**/*.js	File globbing pattern to find JavaScript modules in this project
excludeModulePattern	string	``	File globbing pattern to exclude when looking for JavaScript modules in this project
cutFileCompletionExtensions	array	.js,.jsx,.css,.less,.scss,.hbs,.html	File extensions to cut, if the file name is offered in module path completion
includeFileCompletionExtensions	array	``	Only the specified file extensions will be included for module path completion; all will be included, if empty
excludeFileCompletionExtensions	array	``	The specified file extensions will not be included for module path completion
modulePath	string	.	Module path relative to workspace root
onlyNavigateToFile	boolean	false	When set to true, it will prevent the final search for the identifier in the landing module and instead just reference the file.
pluginExtensions	object	{}	Assigns default file extensions to target module paths used with RequireJS plugins
moduleProcessingBatchSize	number	30	How many documents should be opened and searched before cancelling of the operation is possible

Disable Functionality

If you want to omit a provider or a command registered by this extension, you can set the corresponding property to false: enableDefinitionProvider, enableReferenceProvider, enableCompletionItemProvider, enableHoverProvider, enableRenameProvider, showGoToDefinitionModuleCommand, showRenameExportedSymbolCommand.

Plugins and File Extensions

If you use RequireJS plugins in your projects, which do not require appending file extensions to their target modules, you will need to supply these extensions too. For example:

"requireModuleSupport.pluginExtensions": {
  "css": ".css"
}

This will ensure, that a module reference like "css!views/panel" will be handled as "css!views/panel.css" before resolving the actual module path.

If you use module path completion, you can customise what file extensions will be omitted, because the corresponding plugin does not expect an extension. For example:

"requireModuleSupport.cutFileCompletionExtensions": [
  ".js", ".css"
]

Module Format

If you use pure CommonJS syntax instead of AMD in your sources (not CommonJS wrappers in define() statements) and then compile them together with r.js, which generates AMD wrappers for you, you have to set the following flag to true:

"requireModuleSupport.enableCjsModules"

CJS modules cannot be mixed with other module formats.

The following flags can be set to true to enable the ES module format and the JSX syntax:

"requireModuleSupport.enableEsModules"
"requireModuleSupport.enableJsxModules"

RequireJS Config Files

RequireJS configuration properties like paths, bundles and config are usually maintained in a separate file in a single require.config() statement. This file can be evaluated, when the project is loaded on debug pages, when the project is built (for root components) and in other situations - like this editor plugin.

Example:

// config.js
require.config({
  paths: {
    ui: 'ui/src',        // The "ui" component is located elsewere.
    css: 'libraries/css' // A shortcut for the full module path.
  }
})

// main.js
require(['ui/views/panel'], function (Panel) {
  const panel = new Panel()
  document.body.appendChild(panel.el)
})

// ui/src/views/panel.js
define(['css!./panel'], function () {
  function Panel () {
    this.el = ...
  }
  return Panel
})

// ui/src/views/panel.css
.panel {
  ...
}

If you specify a requireModuleSupport.configFile, which does not contain baseUrl, the value of requireModuleSupport.modulePath will be used as baseUrl.

Performance

The original extension used regexp string matching, which limited the correctness of language construct recognition. This extension traverses a ESTree AST, which has to be parsed from the source files, which slows down the operation.

Once parsed files are cached to avoid repetitive parsing of the same file. You can increase the default cache size for large projects:

"requireModuleSupport.enableEsModules": 50000

While Go To Definition parses only the target module source, Find All References does the same for all files in the project. The static cache size may be increased to satisfy this operation and set to a little more percent to avoid fast exhaustion:

"requireModuleSupport.dynamicModuleCacheSize": true
"requireModuleSupport.dynamicModuleCacheSizeExtra": 5

Find All References can be further optimised by specifying what files should be included and what files should be further excluded from the inclusion pattern:

"requireModuleSupport.includeModulePattern": "src/**/*.js"
"requireModuleSupport.excludeModulePattern": "src/vendor/**/*.js"

Find All References can process a limited batch of files in parallel to prevent CPU exhaustion by analysing thousands of files in parallel:

"requireModuleSupport.excludeModulePattern": 50

You can also limit files, which are suggested by the moule path autocompletion by listing either included or excluded file extensions:

"requireModuleSupport.includeFileCompletionExtensions": [".js", ".css"]
"requireModuleSupport.excludeFileCompletionExtensions": [".txt"]

Contributing

In lieu of a formal styleguide, take care to maintain the existing coding style. Run npm test to validate your changes. Use the examples in the pkg/examples directory to check the effect of your changes.

License

Copyright (c) 2020-2022 Ferdinand Prantl
Copyright (c) 2020 Ali Naci Erdem

Licensed under the MIT license.