Code Inspection and Quick-Fixes in TypeScript

The key features of ReSharper's code analysis are also supported in TypeScript. You can find the detailed information on these features in the corresponding topics of the Code Analysis 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 code analysis features in TypeScript:

• Code Inspection
• Quick-fixes
  • Add missing imports
  • Implement missing members
  • Rename function overload properly
  • Make public/private
  • Add type annotation
  • Remove question mark
  • Remove ambient function body

Code Inspection

ReSharper's code inspection detects compiler errors and and other code issues in TypeScript files. By default, TypeScript code is inspected in design time. If necessary, you can also run code inspection in specific scope:

Code inspection behavior as well as code generation results depend on the TypeScript project settings. In Visual Studio 2013 and higher, you can configure the first two of this settings in the project property editor (right-click on the project and choose Properties). In Visual Studio 2012, you can only change these properties manually by editing the project file (.cproj).

• ECMAScript version (TargetEsVersion)
  If the version is lower than 5, ReSharper detects usages of get and set as errors. If the version is 5 or greater, then ReSharper detects octal literals as errors and suggests replacing them with hexadecimal or decimal literals.
• Allow implicit 'any' types (NotImplicitAny)
  Depending on this property, ReSharper either detects implicit 'any' types (e.g. var a; a = 5;) as errors or not.
• TypeScriptNoResolve
  If this option is set to 'true', ReSharper detects usages of external modules as errors.

Code inspection behavior also depends on the options configured in the Code Editing | TypeScript | Code Style page of ReSharper options. For more information, see Code Style Assistance in TypeScript.

Quick-fixes

ReSharper provides dozens of quick-fixes for TypeScript. Here are some examples:

Add missing imports

If ReSharper detects types that have not been imported in the current file, it highlights them and suggests to add all missing imports at once. For more information, see Importing Missing Namespaces.

Implement missing members

ReSharper suggests generating non-implemented members automatically:

Rename function overload properly

If the names of function overloads are not the same because of a typo, ReSharper highlights mismatching name and suggests a quick-fix:

Make public/private

The default member accessibility is public, but if you explicitly specify a function as private, then all its overloads should have the same modifier. If it is not so, ReSharper highlights that and suggests changes.

Add type annotation

When type is not specified, the variable is highlighted. Press Alt+Enter to display the list of quick-fixes and apply the following one. Necessary type annotation will be added.

Remove question mark

In TypeScript optional parameters can't have default values. If they by accident have, you can either remove a question mark or remove the initializer.

Remove ambient function body

There is no need to keep unnecessary constructs in your code. In attempt to make code readable, ReSharper suggests removing ambient function bodies, for example.