Merge pull request #222 from dylansturg/accurate_decltypes

Specify the type of decl to rename in AlwaysUseLowerCamelCase.

Author: allevato

Sources/SwiftFormatRules/AlwaysUseLowerCamelCase.swift

@@ -55,7 +55,8 @@ public final class AlwaysUseLowerCamelCase: SyntaxLintRule {
       guard let pat = binding.pattern.as(IdentifierPatternSyntax.self) else {
         continue
       }
-      diagnoseLowerCamelCaseViolations(pat.identifier, allowUnderscores: false)
+      diagnoseLowerCamelCaseViolations(
+        pat.identifier, allowUnderscores: false, description: identifierDescription(for: node))
     }
     return .skipChildren
   }
@@ -64,26 +65,47 @@ public final class AlwaysUseLowerCamelCase: SyntaxLintRule {
     // 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)
-    diagnoseLowerCamelCaseViolations(node.identifier, allowUnderscores: allowUnderscores)
+    diagnoseLowerCamelCaseViolations(
+      node.identifier, allowUnderscores: allowUnderscores,
+      description: identifierDescription(for: node))
     return .skipChildren
   }
 
   public override func visit(_ node: EnumCaseElementSyntax) -> SyntaxVisitorContinueKind {
-    diagnoseLowerCamelCaseViolations(node.identifier, allowUnderscores: false)
+    diagnoseLowerCamelCaseViolations(
+      node.identifier, allowUnderscores: false, description: identifierDescription(for: node))
     return .skipChildren
   }
 
-  private func diagnoseLowerCamelCaseViolations(_ identifier: TokenSyntax, allowUnderscores: Bool) {
+  private func diagnoseLowerCamelCaseViolations(
+    _ identifier: TokenSyntax, allowUnderscores: Bool, description: String
+  ) {
     guard case .identifier(let text) = identifier.tokenKind else { return }
     if text.isEmpty { return }
     if (text.dropFirst().contains("_") && !allowUnderscores) || ("A"..."Z").contains(text.first!) {
-      diagnose(.variableNameMustBeLowerCamelCase(text), on: identifier) {
+      diagnose(.nameMustBeLowerCamelCase(text, description: description), on: identifier) {
         $0.highlight(identifier.sourceRange(converter: self.context.sourceLocationConverter))
       }
     }
   }
 }
 
+/// Returns a human readable description of the node type that can be used to describe the
+/// identifier of the node in diagnostics from this rule.
+///
+/// - Parameter node: A node whose identifier may be used in diagnostics.
+/// - Returns: A human readable description of the node and its identifier.
+fileprivate func identifierDescription<NodeType: SyntaxProtocol>(for node: NodeType) -> String {
+  switch Syntax(node).as(SyntaxEnum.self) {
+  case .enumCaseElement: return "enum case"
+  case .functionDecl: return "function"
+  case .variableDecl(let variableDecl):
+    return variableDecl.letOrVarKeyword.tokenKind == .varKeyword ? "variable" : "constant"
+  default:
+    return "identifier"
+  }
+}
+
 extension ReturnClauseSyntax {
   /// Whether this return clause specifies an explicit `Void` return type.
   fileprivate var isVoid: Bool {
@@ -98,7 +120,9 @@ extension ReturnClauseSyntax {
 }
 
 extension Diagnostic.Message {
-  public static func variableNameMustBeLowerCamelCase(_ name: String) -> Diagnostic.Message {
-    return .init(.warning, "rename variable '\(name)' using lower-camel-case")
+  public static func nameMustBeLowerCamelCase(
+    _ name: String, description: String
+  ) -> Diagnostic.Message {
+    return .init(.warning, "rename \(description) '\(name)' using lower-camel-case")
   }
 }

Tests/SwiftFormatRulesTests/AlwaysUseLowerCamelCaseTests.swift

@@ -19,16 +19,26 @@ final class AlwaysUseLowerCamelCaseTests: LintOrFormatRuleTestCase {
       class UnitTests: XCTestCase {
         func test_HappyPath_Through_GoodCode() {}
       }
+      enum FooBarCases {
+        case UpperCamelCase
+        case lowerCamelCase
+      }
       """
     performLint(AlwaysUseLowerCamelCase.self, input: input)
-    XCTAssertDiagnosed(.variableNameMustBeLowerCamelCase("Test"), line: 1, column: 5)
-    XCTAssertNotDiagnosed(.variableNameMustBeLowerCamelCase("foo"))
-    XCTAssertDiagnosed(.variableNameMustBeLowerCamelCase("bad_name"), line: 3, column: 5)
-    XCTAssertNotDiagnosed(.variableNameMustBeLowerCamelCase("_okayName"))
-    XCTAssertNotDiagnosed(.variableNameMustBeLowerCamelCase("Foo"))
-    XCTAssertDiagnosed(.variableNameMustBeLowerCamelCase("FooFunc"), line: 6, column: 8)
     XCTAssertDiagnosed(
-      .variableNameMustBeLowerCamelCase("test_HappyPath_Through_GoodCode"), line: 9, column: 8)
+      .nameMustBeLowerCamelCase("Test", description: "constant"), line: 1, column: 5)
+    XCTAssertNotDiagnosed(.nameMustBeLowerCamelCase("foo", description: "variable"))
+    XCTAssertDiagnosed(
+      .nameMustBeLowerCamelCase("bad_name", description: "variable"), line: 3, column: 5)
+    XCTAssertNotDiagnosed(.nameMustBeLowerCamelCase("_okayName", description: "variable"))
+    XCTAssertNotDiagnosed(.nameMustBeLowerCamelCase("Foo", description: "struct"))
+    XCTAssertDiagnosed(
+      .nameMustBeLowerCamelCase("FooFunc", description: "function"), line: 6, column: 8)
+    XCTAssertDiagnosed(
+      .nameMustBeLowerCamelCase("test_HappyPath_Through_GoodCode", description: "function"),
+      line: 9, column: 8)
+    XCTAssertDiagnosed(
+      .nameMustBeLowerCamelCase("UpperCamelCase", description: "enum case"), line: 12, column: 8)
   }
 
   func testIgnoresUnderscoresInTestNames() {
@@ -50,21 +60,30 @@ final class AlwaysUseLowerCamelCaseTests: LintOrFormatRuleTestCase {
       }
       """
     performLint(AlwaysUseLowerCamelCase.self, input: input)
-    XCTAssertDiagnosed(.variableNameMustBeLowerCamelCase("Test"), line: 3, column: 5)
-    XCTAssertDiagnosed(.variableNameMustBeLowerCamelCase("My_Constant_Value"), line: 5, column: 14)
-    XCTAssertNotDiagnosed(.variableNameMustBeLowerCamelCase("test_HappyPath_Through_GoodCode"))
-    XCTAssertDiagnosed(.variableNameMustBeLowerCamelCase("FooFunc"), line: 7, column: 16)
     XCTAssertDiagnosed(
-      .variableNameMustBeLowerCamelCase("helperFunc_For_HappyPath_Setup"), line: 8, column: 16)
+      .nameMustBeLowerCamelCase("Test", description: "constant"), line: 3, column: 5)
+    XCTAssertDiagnosed(
+      .nameMustBeLowerCamelCase("My_Constant_Value", description: "constant"), line: 5, column: 14)
+    XCTAssertNotDiagnosed(
+      .nameMustBeLowerCamelCase("test_HappyPath_Through_GoodCode", description: "function"))
+    XCTAssertDiagnosed(
+      .nameMustBeLowerCamelCase("FooFunc", description: "function"), line: 7, column: 16)
+    XCTAssertDiagnosed(
+      .nameMustBeLowerCamelCase("helperFunc_For_HappyPath_Setup", description: "function"),
+      line: 8, column: 16)
     XCTAssertDiagnosed(
-      .variableNameMustBeLowerCamelCase("testLikeMethod_With_Underscores"), line: 9, column: 16)
+      .nameMustBeLowerCamelCase("testLikeMethod_With_Underscores", description: "function"),
+      line: 9, column: 16)
     XCTAssertDiagnosed(
-      .variableNameMustBeLowerCamelCase("testLikeMethod_With_Underscores2"), line: 10, column: 16)
+      .nameMustBeLowerCamelCase("testLikeMethod_With_Underscores2", description: "function"),
+      line: 10, column: 16)
     XCTAssertNotDiagnosed(
-      .variableNameMustBeLowerCamelCase("test_HappyPath_Through_GoodCode_ReturnsVoid"))
+      .nameMustBeLowerCamelCase(
+        "test_HappyPath_Through_GoodCode_ReturnsVoid", description: "function"))
     XCTAssertNotDiagnosed(
-      .variableNameMustBeLowerCamelCase("test_HappyPath_Through_GoodCode_ReturnsShortVoid"))
+      .nameMustBeLowerCamelCase(
+        "test_HappyPath_Through_GoodCode_ReturnsShortVoid", description: "function"))
     XCTAssertNotDiagnosed(
-      .variableNameMustBeLowerCamelCase("test_HappyPath_Through_GoodCode_Throws"))
+      .nameMustBeLowerCamelCase("test_HappyPath_Through_GoodCode_Throws", description: "function"))
   }
 }