Add 'Add Explicit Raw Values' code action

[ayush-that]

resolves #2516.

adds a syntactic refactoring action that converts implicit raw values to explicit ones for enums whose first inherited type is an integer (any width up to Int128/UInt128) or String.

before:

enum Status: Int {
    case active
    case inactive
    case pending = 10
    case archived
}

after:

enum Status: Int {
    case active = 0
    case inactive = 1
    case pending = 10
    case archived = 11
}

design follows the feedback @ahoppen left on #2536: implemented as SyntaxRefactoringCodeActionProvider, only the first inherited type is consulted for the raw value type, raw value expressions are validated as integer literals and the action is suppressed when they cannot be parsed, Int128 and UInt128 are accepted in the type list, and the action is suppressed when there is nothing to transform.

beyond #2536, the action also handles:

• negative integer raw values (case low = -5 followed by implicit cases continues at -4)
• alternate-base integer literals with underscore separators (case bit0 = 0x10 continues at 17)
• backticked case identifiers in String enums (case `default becomes = "default", not = "default")
• integer overflow during continuation (suppresses the action rather than trapping)
• enums containing #if directives (rintaro flagged this on the original issue)
• enums containing freestanding macro expansions
• cases with associated values (suppresses rather than producing case payload = 0(String))

motivation

making implicit raw values explicit is a common refactor before serialising values or relying on their numeric identity. doing it by hand is error-prone once any cases already have explicit values, because the continuation rule must be reapplied for every gap.

modifications

• new Sources/SwiftSyntaxCodeActions/AddExplicitEnumRawValues.swift
• registered in Sources/SwiftSyntaxCodeActions/SyntaxCodeActions.swift and Sources/SwiftSyntaxCodeActions/CMakeLists.txt
• 12 LSP-level tests in Tests/SourceKitLSPTests/CodeActionTests.swift covering positive cases (Int, String, negative continuation, hex continuation, backtick stripping) and negative cases (no raw value type, raw value type not first, all cases explicit, unsupported raw value expression, #if directives, freestanding macros, associated value cases)

result

when the cursor is on an enum declaration with a supported raw value type and at least one case missing an explicit raw value, sourcekit-lsp offers "Add Explicit Raw Values" and inserts the missing values in place. existing positive and negative cases continue to behave as before.

all 12 new tests pass locally.

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

This PR introduces a new SwiftSyntax-based refactoring code action to add explicit raw values to enum cases, along with targeted test coverage and build/registration wiring.

Changes:

• Add AddExplicitEnumRawValues code action provider and register it with the code action registry.
• Add a suite of LSP tests covering Int/String raw value insertion and “not offered” scenarios.
• Introduce a test helper to assert that a code action is not offered at a marker.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
Tests/SourceKitLSPTests/CodeActionTests.swift	Adds tests for the new refactor and a helper to assert non-offering.
Sources/SwiftSyntaxCodeActions/SyntaxCodeActions.swift	Registers the new provider in the global provider list.
Sources/SwiftSyntaxCodeActions/CMakeLists.txt	Adds the new Swift source file to the CMake target.
Sources/SwiftSyntaxCodeActions/AddExplicitEnumRawValues.swift	Implements the refactor logic for adding explicit enum raw values.

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[ahoppen]

This looks great. Thank you @ayush-that. I just have two

[ahoppen]

This looks great. Thank you 🙏🏽

[ahoppen]

@swift-ci Please test

[ahoppen]

@swift-ci Please test Windows