Merge pull request swiftlang#295 from dylansturg/silence_override_warnings

Don't emit AlwaysUseLowerCamelCase for decls that `override`

Author: allevato

Sources/SwiftFormatRules/AlwaysUseLowerCamelCase.swift

@@ -51,6 +51,13 @@ public final class AlwaysUseLowerCamelCase: SyntaxLintRule {
   }
 
   public override func visit(_ node: VariableDeclSyntax) -> SyntaxVisitorContinueKind {
+    // Don't diagnose any issues when the variable is overriding, because this declaration can't
+    // rename the variable. If the user analyzes the code where the variable is really declared,
+    // then the diagnostic can be raised for just that location.
+    if let modifiers = node.modifiers, modifiers.has(modifier: "override") {
+      return .visitChildren
+    }
+
     for binding in node.bindings {
       guard let pat = binding.pattern.as(IdentifierPatternSyntax.self) else {
         continue
@@ -94,6 +101,13 @@ public final class AlwaysUseLowerCamelCase: SyntaxLintRule {
   }
 
   public override func visit(_ node: FunctionDeclSyntax) -> SyntaxVisitorContinueKind {
+    // Don't diagnose any issues when the function is overriding, because this declaration can't
+    // rename the function. If the user analyzes the code where the function is really declared,
+    // then the diagnostic can be raised for just that location.
+    if let modifiers = node.modifiers, modifiers.has(modifier: "override") {
+      return .visitChildren
+    }
+
     // We allow underscores in test names, because there's an existing convention of using
     // underscores to separate phrases in very detailed test names.
     let allowUnderscores = testCaseFuncs.contains(node)

Tests/SwiftFormatRulesTests/AlwaysUseLowerCamelCaseTests.swift

@@ -123,4 +123,25 @@ final class AlwaysUseLowerCamelCaseTests: LintOrFormatRuleTestCase {
     XCTAssertNotDiagnosed(
       .nameMustBeLowerCamelCase("test_HappyPath_Through_GoodCode_Throws", description: "function"))
   }
+
+  func testIgnoresFunctionOverrides() {
+    let input =
+      """
+      class ParentClass {
+        var poorly_named_variable: Int = 5
+        func poorly_named_method() {}
+      }
+
+      class ChildClass: ParentClass {
+        override var poorly_named_variable: Int = 5
+        override func poorly_named_method() {}
+      }
+      """
+
+    performLint(AlwaysUseLowerCamelCase.self, input: input)
+    XCTAssertDiagnosed(
+      .nameMustBeLowerCamelCase("poorly_named_variable", description: "variable"), line: 2, column: 7)
+    XCTAssertDiagnosed(
+      .nameMustBeLowerCamelCase("poorly_named_method", description: "function"), line: 3, column: 8)
+  }
 }