ReSharper Help

Coding Assistance in TypeScript

Most of ReSharper's coding assistance features are also supported in TypeScript. You can find the detailed information on these features in the corresponding topics of the Coding Assistance section. In the main topic of the section, you can also find the feature matrix and check what exactly is supported in TypeScript.

In this topic, you can find some examples of using coding assistance features in TypeScript:

Syntax highlighting

ReSharper recognises *.ts and *.d.ts files, and highlights source code within such files according to the predefined colors. You can change colors and fonts at any time. For more information, see Configuring Fonts and Colors.

Code completion

As usual, you can use Code completion features to ease code writing. TypeScript is an object-oriented programming language, so we can define types and members. For example, ReSharper suggests members of the current instance after this keyword.

ReSharper_by_Language__TypeScript__Code_Completion_01

ReSharper also takes into account the right level of abstraction. Consider the example below. After a new instance of the Vector object is initialized, ReSharper displays all available members in the completion list.
ReSharper_by_Language__TypeScript__Code_Completion_02

The minus and plus methods are public, so they are in the list. The times method is private, so it is excluded from the list.

Context actions

ReSharper provides a set of context actions that target TypeScript code. You can find the full list of these actions in the Code Editing | TypeScript | Context actions page of ReSharper options. If necessary, you can also disable some of the actions using this page.

As soon as a context action becomes available for the current caret position, ReSharper displays the corresponding action indicator Coding_Assistance__Context_Actions__icon_editing to the left of the caret. Sometimes, however, ReSharper provides several contextually available features for the current caret position. In this case, the action indicator corresponding to the action with the highest priority is shown, and all other actions only appear when you expand the action list by clicking on the action indicator or pressing Alt+Enter Context actions have the lowest priority, therefore, they often appear in the bottom of the action list:

Here are some examples of context actions for TypeScript:

Create from usage

You can create declarations of symbols after they have been actually used via the corresponding context action.

ReSharper_by_Language__TypeScript__Context_Actions__create_local_variable_01
Or you can use a data type that doesn't exist yet and declare it later using the following context action.
ReSharper_by_Language__TypeScript__Quick-Fixes__create_module_01

Import type

In some other cases, there is no need to create a new entity. When, for example, you want to use an existing one and the only thing that you you haven't taken into account yet is visibility scope.

ReSharper_by_Language__TypeScript__Context_Actions__import_type_01

Regular Expressions Assistance

ReSharper highlights syntax constructs as well as errors and redundancies in regular expressions:

Highlighting of regular expressions

Highlighting colors have the following meanings:

  • Light Blue – character classes, anchors and quantifiers
  • Light Green – grouping constructs
  • Orange – set constructs
  • Pink and light pink – escape sequence
  • Red with curly underline – errors

Matching brackets in groups, group names and sets are highlighted when you set a caret to one of the delimiters. You can toggle and adjust this highlighting using the Highlight matching delimiters setting in ReSharper Options | Environment | Editor | Editor Appearance.

By default, ReSharper also highlights correct and incorrect escape sequences in strings:

Highlighting of escape sequence in a string

and template strings:

Highlighting of escape sequence in a template string

If necessary, you can turn this highlighting of by clearing the Highlight special characters in string literals check box on the Code Inspection | Settings options page.

ReSharper also provides IntelliSense support for almost all TypeScript regular expression constructs. In the completion list, each construct is shown with a brief description.

Code completion in regular expressions

You can invoke Basic completion (Ctrl+Space) to show elements, available for the current scope.

Quick Documentation

With ReSharper, you can quickly review the documentation on TypeScript symbols right in the editor. JSDoc comments will appear in a tooltip. All tags will be presented as sections:

ReSharper showing JSDoc comments in a tooltip

To view the documentation of a symbol, place the caret on it and press Ctrl+Q or choose ReSharper | Edit | Show Quick Documentation in the main menu.

For more information, see Quick Documentation.

See Also

Last modified: 21 September 2015