WebStorm 2018.3 Help

TypeScript

WebStorm supports developing, running, and debugging TypeScript source code. WebStorm recognizes *.ts files and provides full range of coding assistance for editing them without any additional steps from your side. TypeScript files are marked with the TypeScript file icon.

TypeScript-aware coding assistance includes completion for keywords, labels, variables, parameters, and functions, error and syntax highlighting, formatting, numerous code inspections and quick-fixes, as well as common and TypeScript-specific refactoring. WebStorm also verifies and compiles TypeScript into JavaScript on the fly.

Verifying TypeScript and compiling it into JavaScript

WebStorm verifies TypeScript code mainly based on the data from the TypeScript Language Service which also compiles TypeScript into JavaScript.

All the detected syntax and compilation errors are reported in the Errors and Compile errors tabs of the TypeScript Tool Window. For each error, WebStorm provides a brief description and information about the number of the line where it occurred.

The Console tab shows the log of the TypeScript Language Service since the tool window was opened.

To configure integration with the TypeScript Language Service

  1. In the Settings/Preferences dialog (Ctrl+Alt+S), click TypeScript under Languages and Frameworks. The TypeScript page opens.

  2. Specify the Node.js interpreter to use. This can be a local Node.js interpreter or a Node.js on Windows Subsystem for Linux.

  3. From the TypeScript drop-down list, choose the version of the TypeScript to use (WebStorm displays the currently chosen version).
    • By default, the typescript package from the project's node_modules folder is used.

    • Bundled: choose this option to use the typescript package that comes bundled with WebStorm without attempting to find another one.

    • Select: choose this option to use a custom typescript package instead of the one bundled with WebStorm. Choose the path to the relevant package in the dialog that opens.

  4. Make sure the TypeScript Language Service checkbox is selected.

  5. Use the controls below to configure the behaviour of the TypeScript Language Service and enable or disable integration with the Angular language service.

  6. In the Options field, specify the command line options to be passed to the TypeScript Language Service when the tsconfig.json file is not found. See the list of acceptable options at TSC arguments. Note that the -w or --watch (Watch input files) option is irrelevant.

To monitor syntax errors

  • Open the TypeScript tool window (View | Tool Windows | TypeScript) and switch to the Errors tab.

    The tab lists the discrepancies in the code detected by the TypeScript Language Service. The list is updated dynamically as you change your code.

    By default, the list contains only the errors from the file in the active editor tab and the full path to this file is displayed at the top. To show the errors across the entire project, press the Show project errors toggle button Show project errors toggle button on the toolbar. Error messages are grouped by files in which they were detected.

    ws_ts_toolwindow_syntax_errors.png

    To navigate to the code in question, double-click the corresponding error message or select it and choose Jump to Source on the context menu.

    ws_ts_toolwindow_syntax_errors_jump_to_source.png

To monitor compilation errors

  • Open the TypeScript tool window (View | Tool Windows | TypeScript) and switch to the Compile errors tab.

    The tab opens when you click Compile all button and choose the compilation scope from the list:

    ws_ts_toolwindow_compilation_errors.png

    The tab lists all the compilation errors detected in the chosen scope. This list is not affected by changes you make to your code and is updated only when you invoke compilation manually again.

    Error messages are grouped by files in which they were detected. To navigate to the code in question, double-click the corresponding error message or select it and choose Jump to Source on the context menu.

    ws_ts_toolwindow_syntax_errors_jump_to_source.png

Viewing parameter hints

Parameter hints show the names of parameters in methods and functions to make your code easier to read. By default, parameter hints are shown only for values that are literals or function expressions but not for named objects.

ws_typescript_parameter_hints.png

To configure parameter hints

  1. In the Settings/Preferences dialog (Ctrl+Alt+S) box (Ctrl+Alt+S), click General under Editor, then click Appearance. The Appearance page opens.

  2. Click Configure next to the Show parameter name hint checkbox (the checkbox is selected by default).

  3. In the Configure Parameter Name Hints dialog that opens, select the Show name for all arguments checkbox in the Options area.

Viewing inferred type information

To see the inferred type of an object, hold on macOS or Ctrl on Windows and Linux and hover the mouse pointer over it.

ws_typescript_inferred_types.png

Using JavaScript libraries in TypeScript

When working with JavaScript libraries in TypeScript, you need to install type declarations for them. WebStorm reminds you to install them via npm and updates your package.json file accordingly.

To install the type declarations

  1. Position the cursor at the warning and press Alt+Enter.

  2. Select the suggestion and press Enter.

    ws_ts_add_types.png

Documentation look-up

WebStorm lets you get reference for symbols from your project and from its dependencies, for symbols defined in external libraries, and for standard JavaScript APIs because TypeScript implements all of them.

The documentation is shown in a Documentation pop-up window that helps navigate to the related symbols via hyperlinks, and provides a toolbar for moving back and forth through the already navigated pages.

To view documentation for a symbol at caret

  • Press Ctrl+Q or choose View | Quick Documentation Lookup on the main menu. The reference for the symbol is shown in the Documentation pop-up window.

    For standard JavaScript methods available in TypeScript, WebStorm also shows a link to the corresponding MDN article.

    ws_ts_doc_from_mdn.png

To view the MDN documentation for a symbol at caret, do one of the following:

  • In the Documentation window (Ctrl+Q), click the MDN link.

  • Press Shift+F1 or choose View | External Documentation on the main menu.

Refactoring code

WebStorm provides both common refactoring procedures, such as rename/move, etc., and TypeScript-specific refactoring procedures, such as change signature, extract parameter, extract variable. See Copying, renaming, and moving files and folders and Refactoring TypeScript for details.

Auto import in TypeScript

WebStorm can generate import statements for modules, classes, components, and any other TypeScript symbols that are exported. By default, WebStorm adds import statements when you complete TypeScript symbols.

When you type your code or paste a fragment with a symbol that is not yet imported, WebStorm can also generate an import statement for this symbol. If there is only one source to import the symbol from, WebStorm inserts an import statement silently. Otherwise, use an import popup or a dedicated import quick-fix.

To add import statements on code completion

  1. In the Settings/Preferences dialog (Ctrl+Alt+S), click General under Editor, and then click Auto Import. The Auto Import page opens.

  2. In the TypeScript/JavaScript area, select the Add TypeScript imports automatically and On code completion checkboxes.

To add import statements on typing or pasting code

  1. In the Settings/Preferences dialog (Ctrl+Alt+S), click General under editor, and then click Auto Import. The Auto Import page opens.

  2. In the TypeScript/JavaScript area, select the Add TypeScript imports automatically and Unambiguous imports on the fly checkboxes.

Using import popups

If for some reason an import statement for a TypeScript symbol was not added on completion or editing, WebStorm shows you a popup that suggests importing the symbol. To accept the suggestion, press Alt+Enter:

ws_import_pop_up.png
If there's more than one possible source of import, WebStorm informs you about that:
ws_import_pop_up_multiple_choices.png
Pressing Alt+Enter in this case opens a list of suggestions:
ws_import_multiple_choices_suggestion_list.png

To hide import popups

  1. In the Settings/Preferences dialog (Ctrl+Alt+S), click General under editor, and then click Auto Import. The Auto Import page opens.

  2. Clear With import popup checkbox.

Using import quick-fixes

You can always add an import statement via the dedicated quick-fix:

Auto import with quick-fix: no choices
When you choose Add import statement WebStorm adds an import:
Auto import with quick-fix: import statement added
If there are several sources to import a symbol from, WebStorm shows you a suggestion list:
Auto import with quick-fix, multiple choices: suggestion list
If the TypeScript Language Service is enabled in your project, you can also use its suggestion:
Auto import with suggestion from the TypeScript Language Service: no choices
If there are several sources to import a symbol from, the TypeScript Language Service shows several suggestions:
Auto import with suggestion from the TypeScript Language Service: multiple choices

Last modified: 19 November 2018

See Also

Reference:

Language and Framework-Specific Guidelines: