Add symbol name unit tests

Tests/SwiftSyntaxTest/SymbolNameTests.swift

@@ -0,0 +1,326 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2024 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+import SwiftSyntax
+import XCTest
+
+final class SymbolNameTests: XCTestCase {
+
+  // MARK: - Functions
+
+  func testFunctionNameWithoutParameters() {
+    assertSymbolName(ofFunction: "func name() {}", expecting: "name()")
+  }
+
+  func testFunctionNameWithSingleNamedParameter() {
+    assertSymbolName(ofFunction: "func name(one: Int) {}", expecting: "name(one:)")
+  }
+
+  func testFunctionNameWithSingleUnnamedParameter() {
+    assertSymbolName(ofFunction: "func name(_: Int) {}", expecting: "name(_:)")
+  }
+
+  func testFunctionNameWithExternalParameterName() {
+    assertSymbolName(ofFunction: "func name(one two: Int) {}", expecting: "name(one:)")
+  }
+
+  func testFunctionNameWithExplicitExternalParameterName() {
+    assertSymbolName(ofFunction: "func name(one _: Int) {}", expecting: "name(one:)")
+  }
+
+  func testFunctionNameWithImplicitExternalParameterName() {
+    assertSymbolName(ofFunction: "func name(_ two: Int) {}", expecting: "name(_:)")
+  }
+
+  func testFunctionNameWithOnlyAnonymousParameters() {
+    assertSymbolName(ofFunction: "func name(_ _: Int) {}", expecting: "name(_:)")
+  }
+
+  func testFunctionNameWithMultipleNamedParameters() {
+    assertSymbolName(ofFunction: "func name(one two: Int, three: Int) {}", expecting: "name(one:three:)")
+  }
+
+  func testFunctionNameWithAllParametersHavingExternalNames() {
+    assertSymbolName(ofFunction: "func name(one two: Int, three four: Int) {}", expecting: "name(one:three:)")
+  }
+
+  func testFunctionNameWithMixedNamedAndAnonymousParameters() {
+    assertSymbolName(ofFunction: "func name(one two: Int, _ four: Int) {}", expecting: "name(one:_:)")
+  }
+
+  func testFunctionNameWithAllAnonymousParameters() {
+    assertSymbolName(ofFunction: "func name(_ two: Int, _ four: Int) {}", expecting: "name(_:_:)")
+  }
+
+  func testFunctionNameWithBackticks() {
+    assertSymbolName(ofFunction: "func `name`() {}", expecting: "`name`()")
+  }
+
+  func testFunctionNameWithParameterNameInBackticks() {
+    assertSymbolName(ofFunction: "func name(`one`: Int) {}", expecting: "name(`one`:)")
+  }
+
+  func testOperatorFunctionName() {
+    assertSymbolName(ofFunction: "func == (one: Int, two: Int)", expecting: "==(one:two:)")
+  }
+
+  // MARK: - Initializer
+
+  func testInitializerWithoutParameters() {
+    assertSymbolName(ofInitializer: "init() {}", expecting: "init()")
+  }
+
+  func testInitializerWithSingleNamedParameter() {
+    assertSymbolName(ofInitializer: "init(one: Int) {}", expecting: "init(one:)")
+  }
+
+  func testInitializerWithSingleUnnamedParameter() {
+    assertSymbolName(ofInitializer: "init(_: Int) {}", expecting: "init(_:)")
+  }
+
+  func testInitializerWithExternalParameterName() {
+    assertSymbolName(ofInitializer: "init(one two: Int) {}", expecting: "init(one:)")
+  }
+
+  func testInitializerWithExplicitExternalParameterName() {
+    assertSymbolName(ofInitializer: "init(one _: Int) {}", expecting: "init(one:)")
+  }
+
+  func testInitializerWithImplicitExternalParameterName() {
+    assertSymbolName(ofInitializer: "init(_ two: Int) {}", expecting: "init(_:)")
+  }
+
+  func testInitializerWithOnlyAnonymousParameters() {
+    assertSymbolName(ofInitializer: "init(_ _: Int) {}", expecting: "init(_:)")
+  }
+
+  func testInitializerWithMultipleNamedParameters() {
+    assertSymbolName(ofInitializer: "init(one two: Int, three: Int) {}", expecting: "init(one:three:)")
+  }
+
+  func testInitializerWithAllParametersHavingExternalNames() {
+    assertSymbolName(ofInitializer: "init(one two: Int, three four: Int) {}", expecting: "init(one:three:)")
+  }
+
+  func testInitializerWithMixedNamedAndAnonymousParameters() {
+    assertSymbolName(ofInitializer: "init(one two: Int, _ four: Int) {}", expecting: "init(one:_:)")
+  }
+
+  func testInitializerWithAllAnonymousParameters() {
+    assertSymbolName(ofInitializer: "init(_ two: Int, _ four: Int) {}", expecting: "init(_:_:)")
+  }
+
+  func testInitializerWithNameInBackticks() {
+    assertSymbolName(ofInitializer: "init(`one`: Int) {}", expecting: "init(`one`:)")
+  }
+
+  // MARK: - Subscript
+
+  func testSubscriptNameWithoutParameters() {
+    assertSymbolName(ofSubscript: "subscript() -> Int { 0 }", expecting: "subscript()")
+  }
+
+  func testSubscriptNameWithSingleNamedParameter() {
+    assertSymbolName(ofSubscript: "subscript(index: Int) -> Int { 0 }", expecting: "subscript(_:)")
+  }
+
+  func testSubscriptNameWithSingleUnnamedParameter() {
+    assertSymbolName(ofSubscript: "subscript(_: Int) -> Int { 0 }", expecting: "subscript(_:)")
+  }
+
+  func testSubscriptNameWithExternalParameterName() {
+    assertSymbolName(ofSubscript: "subscript(index i: Int) -> Int { 0 }", expecting: "subscript(index:)")
+  }
+
+  func testSubscriptNameWithExplicitExternalParameterName() {
+    assertSymbolName(ofSubscript: "subscript(index _: Int) -> Int { 0 }", expecting: "subscript(index:)")
+  }
+
+  func testSubscriptNameWithImplicitExternalParameterName() {
+    assertSymbolName(ofSubscript: "subscript(_ i: Int) -> Int { 0 }", expecting: "subscript(_:)")
+  }
+
+  func testSubscriptNameWithOnlyAnonymousParameters() {
+    assertSymbolName(ofSubscript: "subscript(_ _: Int) -> Int { 0 }", expecting: "subscript(_:)")
+  }
+
+  func testSubscriptNameWithMultipleNamedParameters() {
+    assertSymbolName(ofSubscript: "subscript(x: Int, y: Int) -> Int { 0 }", expecting: "subscript(_:_:)")
+  }
+
+  func testSubscriptNameWithMultipleParametersAndExternalNames() {
+    assertSymbolName(
+      ofSubscript: "subscript(indexX x: Int, indexY y: Int) -> Int { 0 }",
+      expecting: "subscript(indexX:indexY:)"
+    )
+  }
+
+  func testSubscriptNameWithParameterNameInBackticks() {
+    assertSymbolName(ofSubscript: "subscript(`index` i: Int) -> Int { 0 }", expecting: "subscript(`index`:)")
+  }
+
+  // MARK: - Enum Case Element
+
+  func testEnumCaseElementWithoutAssociatedValues() {
+    assertSymbolName(ofEnumCase: "case a", expecting: "a")
+  }
+
+  func testEnumCaseElementWithSingleNamedAssociatedValue() {
+    assertSymbolName(ofEnumCase: "case b(c: Int)", expecting: "b(c:)")
+  }
+
+  func testEnumCaseElementWithSingleUnnamedAssociatedValue() {
+    assertSymbolName(ofEnumCase: "case d(Int)", expecting: "d(_:)")
+  }
+
+  func testEnumCaseElementWithSingleUnnamedAssociatedValueWithUnderscore() {
+    assertSymbolName(ofEnumCase: "case e(_: Int)", expecting: "e(_:)")
+  }
+
+  func testEnumCaseElementWithMultipleNamedAssociatedValues() {
+    assertSymbolName(ofEnumCase: "case f(g: Int, h: Int)", expecting: "f(g:h:)")
+  }
+
+  func testEnumCaseElementNameWithBackticks() {
+    assertSymbolName(ofEnumCase: "case `i`", expecting: "`i`")
+  }
+
+  func testEnumCaseElementWithAssociatedValueNameInBackticks() {
+    assertSymbolName(ofEnumCase: "case j(`k`: Int)", expecting: "j(`k`:)")
+  }
+
+  // MARK: - Macro
+
+  func testMacroDeclWithoutParameters() {
+    assertSymbolName(ofMacroDecl: "macro myMacro()", expecting: "myMacro()")
+  }
+
+  func testMacroDeclWithSingleNamedParameter() {
+    assertSymbolName(ofMacroDecl: "macro myMacro(x: Int)", expecting: "myMacro(x:)")
+  }
+
+  func testMacroDeclWithSingleUnnamedParameter() {
+    assertSymbolName(ofMacroDecl: "macro myMacro(_: Int)", expecting: "myMacro(_:)")
+  }
+
+  func testMacroDeclWithExternalParameterName() {
+    assertSymbolName(ofMacroDecl: "macro myMacro(external internal: Int)", expecting: "myMacro(external:)")
+  }
+
+  func testMacroDeclWithExplicitExternalParameterName() {
+    assertSymbolName(ofMacroDecl: "macro myMacro(external _: Int)", expecting: "myMacro(external:)")
+  }
+
+  func testMacroDeclWithImplicitExternalParameterName() {
+    assertSymbolName(ofMacroDecl: "macro myMacro(_ internal: Int)", expecting: "myMacro(_:)")
+  }
+
+  func testMacroDeclWithMultipleNamedParameters() {
+    assertSymbolName(ofMacroDecl: "macro myMacro(x: Int, y: String)", expecting: "myMacro(x:y:)")
+  }
+
+  func testMacroDeclWithAllParametersHavingExternalNames() {
+    assertSymbolName(
+      ofMacroDecl: "macro myMacro(external1 internal1: Int, external2 internal2: String)",
+      expecting: "myMacro(external1:external2:)"
+    )
+  }
+
+  func testMacroDeclWithMixedNamedAndUnnamedParameters() {
+    assertSymbolName(ofMacroDecl: "macro myMacro(x: Int, _: String)", expecting: "myMacro(x:_:)")
+  }
+
+  func testMacroDeclWithNameInBackticks() {
+    assertSymbolName(ofMacroDecl: "macro `myMacro`()", expecting: "`myMacro`()")
+  }
+
+  func testMacroDeclWithParameterNameInBackticks() {
+    assertSymbolName(ofMacroDecl: "macro myMacro(`x`: Int)", expecting: "myMacro(`x`:)")
+  }
+
+  func testMacroDeclWithExternalParameterNameInBackticks() {
+    assertSymbolName(ofMacroDecl: "macro myMacro(`external` internal: Int)", expecting: "myMacro(`external`:)")
+  }
+}
+
+// MARK: - Assertions
+
+private func assertSymbolName(
+  ofFunction function: DeclSyntax,
+  expecting expectedSymbolName: String,
+  file: StaticString = #filePath,
+  line: UInt = #line
+) {
+  guard let functionDecl = function.as(FunctionDeclSyntax.self) else {
+    XCTFail("Expected function declaration not found.", file: file, line: line)
+    return
+  }
+
+  XCTAssertEqual(functionDecl.symbolName, expectedSymbolName, file: file, line: line)
+}
+
+private func assertSymbolName(
+  ofInitializer initializer: DeclSyntax,
+  expecting expectedSymbolName: String,
+  file: StaticString = #filePath,
+  line: UInt = #line
+) {
+  guard let initializerDecl = initializer.as(InitializerDeclSyntax.self) else {
+    XCTFail("Expected initializer declaration not found.", file: file, line: line)
+    return
+  }
+
+  XCTAssertEqual(initializerDecl.symbolName, expectedSymbolName, file: file, line: line)
+}
+
+private func assertSymbolName(
+  ofSubscript subscriptDeclaration: DeclSyntax,
+  expecting expectedSymbolName: String,
+  file: StaticString = #filePath,
+  line: UInt = #line
+) {
+  guard let subscriptDecl = subscriptDeclaration.as(SubscriptDeclSyntax.self) else {
+    XCTFail("Expected subscript declaration not found.", file: file, line: line)
+    return
+  }
+
+  XCTAssertEqual(subscriptDecl.symbolName, expectedSymbolName, file: file, line: line)
+}
+
+private func assertSymbolName(
+  ofEnumCase enumCaseDeclaration: DeclSyntax,
+  expecting expectedSymbolName: String,
+  file: StaticString = #filePath,
+  line: UInt = #line
+) {
+  guard let enumCaseDecl = enumCaseDeclaration.as(EnumCaseDeclSyntax.self),
+    let enumCaseElement = enumCaseDecl.elements.first
+  else {
+    XCTFail("Expected enum case element declaration not found.", file: file, line: line)
+    return
+  }
+  XCTAssertEqual(enumCaseElement.symbolName, expectedSymbolName, file: file, line: line)
+}
+
+private func assertSymbolName(
+  ofMacroDecl macroDecl: DeclSyntax,
+  expecting expectedSymbolName: String,
+  file: StaticString = #filePath,
+  line: UInt = #line
+) {
+  guard let macroDeclSyntax = macroDecl.as(MacroDeclSyntax.self) else {
+    XCTFail("Expected macro declaration not found.", file: file, line: line)
+    return
+  }
+
+  XCTAssertEqual(macroDeclSyntax.symbolName, expectedSymbolName, file: file, line: line)
+}