P42 Refactoring for Visual Studio Code (alpha)

P42 adds refactorings for modernizing and simplifying your JavaScript (and TypeScript) to Visual Studio Code.

Features

Refactoring Suggestions in the Editor

Refactor suggestions are indicated as blue information underlines in applicable code segments. They can be invoked as quick fixes or through the refactoring menu. See Refactorings below for details.

Default Parameter Example

Bulk Refactoring for Folders

For folders in the Explorer, there is a new "Refactor... [P42]" command for bulk refactorings. You can select a code modernization refactoring from a dialog. The selected refactoring is then applied to the files in the folder.

Recommended Workflow

Get you workspace in a clean state, e.g. by committing or stashing current changes, or by switching to a clean branch.
Run the P42 code refactoring on the folders you want to update.
Thoroughly review the individual changes in the diff viewer and revert / fix them as needed. Refactorings need to cover many edge cases, so there is a chance that some changes may lose comments, break formatting, or affect the semantics. If you find bugs, please report them here: https://github.com/p42ai/refactor-vscode/issues
Run your test suites to ensure nothing broke unexpectedly.
Commit the changes.

Refactorings

Convert default value assignments to parameter default values

Default Parameter Example

Shorten default value assignments with nullish coalescing operator

Nullish Coalescing Operator Example

Combine nested if-statements into single if statement with '&&' condition

Nested If Example

Combine nested single `if` inside `else` into `else if`

Nested Else Example

Convert check of last string character to 'String.endsWith()

String.endsWith() Example

Convert indexed for loop to for..of loop

For..of Loop Example

Convert check for null and undefined into '== null' comparison

== null Example

Combine return statements into a single return with a conditional expression

Return Ternary Example

Split combined variable declaration into separate declarations

Unchain Variable Declaration Example

Convert to optional chain expressions

Optional Chaining Example

Convert '.apply()' call to use spread operator (...)

Spread Operator Example

Convert 'var' variable declarations that can be block scoped to let and const

Block Scoped Variable Example

Convert functions to arrow functions

Convert string concatenation to template literals

Template Literal Example

Configuration

The p42.toml file in the workspace root contains the P42 configuration.

Currently, individual refactorings can be enabled and disabled. By default, all refactorings are enabled.

To disable a refactoring, add a section with "refactoring.$refactoring-id" and set enabled to false, for example:

[refactoring.optional-chaining]
enabled = false

The refactoring ids are displayed as grayed-out text in parentheses in the hover messages.

FAQ

Does P42 analyse my code in the P42 cloud? No. Your code remains on your computer and all P42 code analysis happens on your computer. No code or other data is transferred to a cloud service by the P42 extension.
How can I disable a refactoring / suggestions? You can disable them by adding a section in the p42.config.toml configuration file. See Configuration above.

License

This software is offered free of charge by
P42 Software UG (haftungsbeschränkt), Pappelallee 78/79, 10437 Berlin, Germany.

The software may not be redistributed or sold without permission.

P42 Software UG (haftungsbeschränkt) is only liable for defects in accordance with applicable law.

Open Source Libraries

See DISCLAIMER.txt.

JavaScript Refactoring (P42)

P42