ReSharper 2017.1 Help

Code Syntax Style: Bodies of Function Members

Starting from C# 6.0, you can declare function members using expression bodies, which look very similar to lambda expressions. You can use expression-bodied methods and properties to further simplify the syntax of simple implementations.

If you prefer to stick to either expression-bodied or block-bodied implementations for simple function members, ReSharper lets you configure your preferences separately for different kinds of members and maintain the consistency of your preferences throughout your codebase.

ReSharper helps you enforce preferences for expression-bodied functions in the existing code and takes your preferences into account when it produces new code with code completion and code generation features, applies code templates and performs refactorings.

In this topic:

Enforcing preferences for expression-bodied functions

ReSharper can help you check all simple members for compliance with your preferences and if they do not comply, it highlights such implementations and suggests the corresponding quick-fix or fix in scope. Default ReSharper's preferences say that expression body is preferred for properties, indexers, and events:

ReSharper. 'To expression body' quick-fix

For all other kinds of members, suggestions are disabled by default. However, you can configure your preferences in a different way, so that, for example, ReSharper suggests you to convert expression-bodied methods to block bodies:

ReSharper. 'To statement body' quick-fix

Another option to enforce preferences for expression-bodied functions in a bulk mode is code cleanup. You can either run code cleanup with the default profile Default: Full Cleanup or run the cleanup with a custom profile solely targeted at your specific task as described below.

To apply preferences for expression-bodied functions with code cleanup

  1. Open the Code Cleanup options: ReSharper | Options | Code Editing | Code Cleanup.
  2. Create a new profile as described in the Code Cleanup section. In the Selected profile settings section for the new profile, tick the Apply code body style check box.
  3. Click Save to apply the modifications and let ReSharper choose where to save them, or save the modifications to a specific settings layer using the Save To drop-down list. For more information, see Managing and Sharing ReSharper Settings.
  4. Select the scope where you want to enforce your preferences:
    • Set the caret anywhere in the file to enforce your preferences to the file.
    • Select one or more items in the Solution Explorer to enforce your preferences in the files under these nodes and their child items.
  5. Do one of the following:
    • Press Ctrl+Alt+F or choose ReSharper | Edit | Cleanup Code in the main menu.
    • Right-click anywhere in the text editor or right-click the selection and choose Cleanup Code in the context menu.
  6. In the Code Cleanup dialog that opens, select the newly created profile.
  7. Click Run. ReSharper will enforce your preferences in the selected scope.

If you want to enforce preferences for expression-bodied functions without opening the Code Cleanup dialog, you can bind the created profile to the silent cleanup and run it simply by pressing Ctrl+Shift+Alt+F. You can also create a custom cleanup profile that would combine applying the preferences with other code style tasks.

Configuring preferences for expression-bodied functions

Your function body preferences are saved using the mechanism of shared settings. Among other things, this mechanism allows you to maintain different preferences for different solutions as well as to keep these preferences under a VCS and automatically share them with your team members.

To configure preferences for expression-bodied functions

  1. Go to the Code Editing | C# | Code Style page of ReSharper options.
  2. Modify settings in the Code body category according to your coding practices/standards.
  3. By default, ReSharper applies heuristics to decide whether to convert block bodies of methods to expression bodies. Among other things, this means that ReSharper will not suggest expression bodies for void methods and for methods that contain a lambda expression.
    You can simplify this logic by clearing the Apply style heuristics check box. In this case, the logic is simple: if you choose to use expression body for some kind of members, ReSharper will suggest expression body if the declaration of a member of this kind consists of a single statement.
  4. The Notify with selectors in the right column allow you to set severity levels of code inspections detecting code that differs from your preferences.
  5. Click Save to apply the modifications and let ReSharper choose where to save them, or save the modifications to a specific settings layer using the Save To drop-down list. For more information, see Managing and Sharing ReSharper Settings.

You can also change your preferences for function bodies right in the editor, where a corresponding issue is highlighted:

To change preference of using expression body from the editor

  1. Set the caret to a code issue highlighted by a ReSharper's inspection.
  2. Press Alt+Enter or click on the action indicator to the left of the caret to open the action list.
  3. In the action list, choose Inspection "Use preferred body style..." | Configure code style and then select a desired preference:
    Changing code style preference for member body
  4. Your change will be saved using the smart save logic.
  5. If you need to save the modified style preference in a shared settings layer, click on the Configure code style menu item or press Enter when it is selected. ReSharper will open the Code Editing | C# | Code Style page of ReSharper options where you can modify your preference as needed, click Save To and then choose the desired settings layer.

This feature is supported in the following languages/technologies:

Last modified: 12 October 2017