AppCode 2019.2 Help

TypeScript

AppCode supports developing, running, and debugging TypeScript source code. AppCode 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. AppCode also verifies and compiles TypeScript into JavaScript on the fly.

Verifying TypeScript and compiling it into JavaScript

AppCode 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, AppCode 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.

Configure integration with the TypeScript Language Service

  1. In the Preferences dialog (⌘,), go to Languages and Frameworks | TypeScript. The TypeScript page opens.

  2. Specify the Node.js interpreter to use. If you choose the Project alias, AppCode will automatically use the project default interpreter from the Node interpreter field on the Node.js and NPM page.

    In most cases, AppCode detects the project default interpreter and fills in the field itself. You can also choose another configured local interpreter or click the Browse button and configure a new one.

  3. From the TypeScript list, choose the version of the TypeScript to use (AppCode 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 AppCode without attempting to find another one.

    • Select: choose this option to use a custom typescript package instead of the one bundled with AppCode. 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.

  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.

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 from the context menu.

    ws_ts_toolwindow_syntax_errors_jump_to_source.png

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 from 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

Configure parameter hints

  1. In the Preferences dialog (⌘,), go to Editor | General | 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 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. AppCode reminds you to install them via npm and updates your package.json file accordingly.

Install the type declarations

  1. Position the caret at the warning and press ⌥⏎.

  2. Select the suggestion and press .

    ws_ts_add_types.png

Documentation look-up

AppCode 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 popup that helps navigate to the related symbols via hyperlinks, and provides a toolbar for moving back and forth through the already navigated pages.

View documentation for a symbol at caret

  • Press F1 or choose View | Quick Documentation Lookup from the main menu. The reference for the symbol is shown in the Documentation popup.

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

    ws_ts_doc_from_mdn.png

View the MDN documentation for a symbol at caret

  • In the Documentation window F1, click the MDN link.

  • Alternatively, press ⇧F1 or choose View | External Documentation from the main menu.

AppCode opens the MDN article in the default AppCode browser.

Refactoring code

AppCode provides both common refactoring procedures, such as rename/move, and so on, and TypeScript-specific refactoring procedures, such as change signature, extract parameter, extract variable. See Rename and Move and copy for details.

Auto import in TypeScript

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

See Auto import to learn how to optimize import statements and configure their style.

When you type your code or paste a fragment with a symbol that is not yet imported, AppCode can also generate an import statement for this symbol. If there is only one source to import the symbol from, AppCode 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 Preferences dialog (⌘,), go to Editor | General | 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 Preferences dialog (⌘,), go to Editor | General | 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, AppCode shows you a popup that suggests importing the symbol. To accept the suggestion, press ⌥⏎:

ws_import_pop_up.png

If there's more than one possible source of import, AppCode informs you about that:

ws_import_pop_up_multiple_choices.png

Pressing ⌥⏎ in this case opens a list of suggestions:

ws_import_multiple_choices_suggestion_list.png

To hide import popups

  1. In the Preferences dialog (⌘,), go to Editor | General | 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 AppCode adds an import:

Auto import with quick-fix: import statement added

If there are several sources to import a symbol from, AppCode 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

Configuring syntax highlighting

You can configure TypeScript-aware syntax highlighting according to your preferences and habits.

  1. In the Preferences dialog (⌘,), go to Editor | Color Scheme | TypeScript.

  2. Select the color scheme, accept the highlighting settings inherited from defaults or customize them as described in Configuring Colors and Fonts.

Last modified: 10 October 2019