Add TestCaseAccessibilityRule

CHANGELOG.md

@@ -10,7 +10,9 @@
 
 #### Enhancements
 
-* None.
+* Add `test_case_accessibility` rule.  
+  [Keith Smiley](https://github.com/keith)
+  [#3376](https://github.com/realm/SwiftLint/issues/3376)
 
 #### Bug Fixes
 

Source/SwiftLintFramework/Helpers/XCTestHelpers.swift

@@ -0,0 +1,24 @@
+import SourceKittenFramework
+
+private let testFunctionNames: Set = [
+    "setUp()",
+    "setUpWithError()",
+    "tearDown()",
+    "tearDownWithError()"
+]
+
+private let testVariableNames: Set = [
+    "allTests"
+]
+
+enum XCTestHelpers {
+    static func isXCTestMember(kind: SwiftDeclarationKind, name: String) -> Bool {
+        if SwiftDeclarationKind.functionKinds.contains(kind) {
+            return name.hasPrefix("test") || testFunctionNames.contains(name)
+        } else if SwiftDeclarationKind.variableKinds.contains(kind) {
+            return testVariableNames.contains(name)
+        }
+
+        return false
+    }
+}

Source/SwiftLintFramework/Models/MasterRuleList.swift

@@ -162,6 +162,7 @@ public let masterRuleList = RuleList(rules: [
     SwitchCaseAlignmentRule.self,
     SwitchCaseOnNewlineRule.self,
     SyntacticSugarRule.self,
+    TestCaseAccessibilityRule.self,
     TodoRule.self,
     ToggleBoolRule.self,
     TrailingClosureRule.self,

Source/SwiftLintFramework/Rules/Lint/EmptyXCTestMethodRule.swift

@@ -33,8 +33,8 @@ public struct EmptyXCTestMethodRule: Rule, OptInRule, ConfigurationProviderRule,
         return dictionary.substructure.compactMap { subDictionary -> StyleViolation? in
             guard
                 let kind = subDictionary.declarationKind,
-                SwiftDeclarationKind.functionKinds.contains(kind),
-                let name = subDictionary.name, isXCTestMethod(name),
+                let name = subDictionary.name,
+                XCTestHelpers.isXCTestMember(kind: kind, name: name),
                 let offset = subDictionary.offset,
                 subDictionary.enclosedVarParameters.isEmpty,
                 subDictionary.substructure.isEmpty else { return nil }
@@ -44,8 +44,4 @@ public struct EmptyXCTestMethodRule: Rule, OptInRule, ConfigurationProviderRule,
                                   location: Location(file: file, byteOffset: offset))
         }
     }
-
-    private func isXCTestMethod(_ method: String) -> Bool {
-        return method.hasPrefix("test") || method == "setUp()" || method == "tearDown()"
-    }
 }

Source/SwiftLintFramework/Rules/Lint/TestCaseAccessibilityRule.swift

@@ -0,0 +1,52 @@
+import SourceKittenFramework
+
+public struct TestCaseAccessibilityRule: Rule, OptInRule, ConfigurationProviderRule, AutomaticTestableRule {
+    public var configuration = TestCaseAccessibilityConfiguration()
+
+    public init() {}
+
+    public static let description = RuleDescription(
+        identifier: "test_case_accessibility",
+        name: "Test case accessibility",
+        description: "Test cases should only contain private non-test members.",
+        kind: .lint,
+        nonTriggeringExamples: TestCaseAccessibilityRuleExamples.nonTriggeringExamples,
+        triggeringExamples: TestCaseAccessibilityRuleExamples.triggeringExamples
+    )
+
+    public func validate(file: SwiftLintFile) -> [StyleViolation] {
+        return testClasses(in: file).flatMap { violations(in: file, for: $0) }
+    }
+
+    // MARK: - Private
+
+    private func testClasses(in file: SwiftLintFile) -> [SourceKittenDictionary] {
+        let dict = file.structureDictionary
+        return dict.substructure.filter { dictionary in
+            guard dictionary.declarationKind == .class else { return false }
+            return dictionary.inheritedTypes.contains("XCTestCase")
+        }
+    }
+
+    private func violations(in file: SwiftLintFile,
+                            for dictionary: SourceKittenDictionary) -> [StyleViolation] {
+        return dictionary.substructure.compactMap { subDictionary -> StyleViolation? in
+            guard
+                let kind = subDictionary.declarationKind,
+                kind != .varLocal,
+                let name = subDictionary.name,
+                !isXCTestMember(kind: kind, name: name),
+                let offset = subDictionary.offset,
+                subDictionary.accessibility?.isPrivate != true else { return nil }
+
+            return StyleViolation(ruleDescription: Self.description,
+                                  severity: configuration.severity,
+                                  location: Location(file: file, byteOffset: offset))
+        }
+    }
+
+    private func isXCTestMember(kind: SwiftDeclarationKind, name: String) -> Bool {
+        return XCTestHelpers.isXCTestMember(kind: kind, name: name)
+            || configuration.methodPrefixes.contains { name.hasPrefix($0) }
+    }
+}

Source/SwiftLintFramework/Rules/Lint/TestCaseAccessibilityRuleExamples.swift

@@ -0,0 +1,79 @@
+internal struct TestCaseAccessibilityRuleExamples {
+    static let nonTriggeringExamples = [
+        // Valid XCTestCase class
+
+        Example("""
+        let foo: String?
+
+        class FooTests: XCTestCase {
+            private let foo: String {
+                let nestedMember = "hi"
+                return nestedMember
+            }
+
+            override static func setUp() {
+                super.setUp()
+            }
+
+            override func setUp() {
+                super.setUp()
+            }
+
+            override func setUpWithError() throws {
+                try super.setUpWithError()
+            }
+
+            override static func tearDown() {
+                super.tearDown()
+            }
+
+            override func tearDown() {
+                super.tearDown()
+            }
+
+            override func tearDownWithError() {
+                try super.tearDownWithError()
+            }
+
+            func testFoo() {
+                XCTAssertTrue(true)
+            }
+        }
+        """),
+
+        // Not an XCTestCase class
+
+        Example("""
+        class Foobar {
+            func setUp() {}
+
+            func tearDown() {}
+
+            func testFoo() {}
+        }
+        """)
+    ]
+
+    static let triggeringExamples = [
+        Example("""
+        class FooTests: XCTestCase {
+            ↓var foo: String?
+            ↓let bar: String?
+
+            ↓static func foo() {}
+
+            ↓func setUp(withParam: String) {}
+
+            ↓func foobar() {}
+
+            ↓func not_testBar() {}
+
+            ↓enum Nested {}
+        }
+
+        final class BarTests: XCTestCase {
+            ↓class Nested {}
+        }
+        """)
+    ]
+}

Source/SwiftLintFramework/Rules/RuleConfigurations/OverridenSuperCallConfiguration.swift

@@ -29,7 +29,9 @@ public struct OverridenSuperCallConfiguration: RuleConfiguration, Equatable {
         "viewWillDisappear(_:)",
         //XCTestCase
         "setUp()",
-        "tearDown()"
+        "setUpWithError()",
+        "tearDown()",
+        "tearDownWithError()"
     ]
 
     var severityConfiguration = SeverityConfiguration(.warning)

Source/SwiftLintFramework/Rules/RuleConfigurations/TestCaseAccessibilityConfiguration.swift

@@ -0,0 +1,27 @@
+public struct TestCaseAccessibilityConfiguration: RuleConfiguration, Equatable {
+    public private(set) var severityConfiguration = SeverityConfiguration(.warning)
+    public private(set) var methodPrefixes: Set<String> = []
+
+    public var consoleDescription: String {
+        return severityConfiguration.consoleDescription +
+        	", method_prefixes: [\(methodPrefixes)]"
+    }
+
+    public mutating func apply(configuration: Any) throws {
+        guard let configuration = configuration as? [String: Any] else {
+            throw ConfigurationError.unknownConfiguration
+        }
+
+        if let severityString = configuration["severity"] as? String {
+            try severityConfiguration.apply(configuration: severityString)
+        }
+
+        if let methodPrefixes = configuration["method_prefixes"] as? [String] {
+            self.methodPrefixes = Set(methodPrefixes)
+        }
+    }
+
+    public var severity: ViolationSeverity {
+        return severityConfiguration.severity
+    }
+}

SwiftLint.xcodeproj/project.pbxproj

@@ -246,10 +246,14 @@
 		BC87573B2195CF2A00CA7A74 /* ModifierOrderRuleExamples.swift in Sources */ = {isa = PBXBuildFile; fileRef = BC8757392195CDD500CA7A74 /* ModifierOrderRuleExamples.swift */; };
 		BCB68283216213130078E4C3 /* CompilerProtocolInitRuleTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = BCB68282216213130078E4C3 /* CompilerProtocolInitRuleTests.swift */; };
 		BFF028AE1CBCF8A500B38A9D /* TrailingWhitespaceConfiguration.swift in Sources */ = {isa = PBXBuildFile; fileRef = BF48D2D61CBCCA5F0080BDAE /* TrailingWhitespaceConfiguration.swift */; };
+		C225E846252E8B2200EDE3E7 /* TestCaseAccessibilityRule.swift in Sources */ = {isa = PBXBuildFile; fileRef = C225E844252E8B1B00EDE3E7 /* TestCaseAccessibilityRule.swift */; };
+		C225E847252E8B2200EDE3E7 /* TestCaseAccessibilityRuleExamples.swift in Sources */ = {isa = PBXBuildFile; fileRef = C225E845252E8B1E00EDE3E7 /* TestCaseAccessibilityRuleExamples.swift */; };
+		C225E849252E8B3B00EDE3E7 /* XCTestHelpers.swift in Sources */ = {isa = PBXBuildFile; fileRef = C225E848252E8B2F00EDE3E7 /* XCTestHelpers.swift */; };
 		C25EBBDF2107884200E27603 /* PrefixedTopLevelConstantRuleTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = C25EBBDD210787B200E27603 /* PrefixedTopLevelConstantRuleTests.swift */; };
 		C25EBBE221078D5F00E27603 /* GlobTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = C25EBBE021078D5B00E27603 /* GlobTests.swift */; };
 		C25EBBE521078DCE00E27603 /* Glob.swift in Sources */ = {isa = PBXBuildFile; fileRef = C25EBBE321078DC700E27603 /* Glob.swift */; };
 		C26330382073DAC500D7B4FD /* LowerACLThanParentRule.swift in Sources */ = {isa = PBXBuildFile; fileRef = C26330352073DAA200D7B4FD /* LowerACLThanParentRule.swift */; };
+		C26522A2252E93AC00BF9C0C /* TestCaseAccessibilityConfiguration.swift in Sources */ = {isa = PBXBuildFile; fileRef = C26522A1252E93AC00BF9C0C /* TestCaseAccessibilityConfiguration.swift */; };
 		C28B2B3D2106DF730009A0FE /* PrefixedConstantRuleConfiguration.swift in Sources */ = {isa = PBXBuildFile; fileRef = C28B2B3B2106DF210009A0FE /* PrefixedConstantRuleConfiguration.swift */; };
 		C2A8D076243C0D0300642BC9 /* IBInspectableInExtensionRule.swift in Sources */ = {isa = PBXBuildFile; fileRef = C2A8D075243C0D0300642BC9 /* IBInspectableInExtensionRule.swift */; };
 		C2B3C1612106F78C00088928 /* ConfigurationAliasesTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = C2B3C15F2106F78100088928 /* ConfigurationAliasesTests.swift */; };
@@ -771,10 +775,14 @@
 		BC8757392195CDD500CA7A74 /* ModifierOrderRuleExamples.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ModifierOrderRuleExamples.swift; sourceTree = "<group>"; };
 		BCB68282216213130078E4C3 /* CompilerProtocolInitRuleTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CompilerProtocolInitRuleTests.swift; sourceTree = "<group>"; };
 		BF48D2D61CBCCA5F0080BDAE /* TrailingWhitespaceConfiguration.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = TrailingWhitespaceConfiguration.swift; sourceTree = "<group>"; };
+		C225E844252E8B1B00EDE3E7 /* TestCaseAccessibilityRule.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = TestCaseAccessibilityRule.swift; sourceTree = "<group>"; };
+		C225E845252E8B1E00EDE3E7 /* TestCaseAccessibilityRuleExamples.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = TestCaseAccessibilityRuleExamples.swift; sourceTree = "<group>"; };
+		C225E848252E8B2F00EDE3E7 /* XCTestHelpers.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = XCTestHelpers.swift; sourceTree = "<group>"; };
 		C25EBBDD210787B200E27603 /* PrefixedTopLevelConstantRuleTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PrefixedTopLevelConstantRuleTests.swift; sourceTree = "<group>"; };
 		C25EBBE021078D5B00E27603 /* GlobTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = GlobTests.swift; sourceTree = "<group>"; };
 		C25EBBE321078DC700E27603 /* Glob.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Glob.swift; sourceTree = "<group>"; };
 		C26330352073DAA200D7B4FD /* LowerACLThanParentRule.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LowerACLThanParentRule.swift; sourceTree = "<group>"; };
+		C26522A1252E93AC00BF9C0C /* TestCaseAccessibilityConfiguration.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = TestCaseAccessibilityConfiguration.swift; sourceTree = "<group>"; };
 		C28B2B3B2106DF210009A0FE /* PrefixedConstantRuleConfiguration.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PrefixedConstantRuleConfiguration.swift; sourceTree = "<group>"; };
 		C2A8D075243C0D0300642BC9 /* IBInspectableInExtensionRule.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = IBInspectableInExtensionRule.swift; sourceTree = "<group>"; };
 		C2B3C15F2106F78100088928 /* ConfigurationAliasesTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ConfigurationAliasesTests.swift; sourceTree = "<group>"; };
@@ -1128,6 +1136,7 @@
 				3BCC04CF1C4F56D3006073C3 /* SeverityLevelsConfiguration.swift */,
 				725094881D0855760039B353 /* StatementModeConfiguration.swift */,
 				787CDE38208E7D41005F3D2F /* SwitchCaseAlignmentConfiguration.swift */,
+				C26522A1252E93AC00BF9C0C /* TestCaseAccessibilityConfiguration.swift */,
 				D450D1DA21F1992E00E60010 /* TrailingClosureConfiguration.swift */,
 				D40F83871DE9179200524C62 /* TrailingCommaConfiguration.swift */,
 				BF48D2D61CBCCA5F0080BDAE /* TrailingWhitespaceConfiguration.swift */,
@@ -1146,6 +1155,7 @@
 				C25EBBE321078DC700E27603 /* Glob.swift */,
 				D4AB0EA11F8993DD00CEC380 /* NamespaceCollector.swift */,
 				4DCB8E7D1CBE43640070FCF0 /* RegexHelpers.swift */,
+				C225E848252E8B2F00EDE3E7 /* XCTestHelpers.swift */,
 			);
 			path = Helpers;
 			sourceTree = "<group>";
@@ -1243,6 +1253,8 @@
 				B89F3BC91FD5ED9000931E59 /* RequiredEnumCaseRule.swift */,
 				D450D1D021EC4A6900E60010 /* StrongIBOutletRule.swift */,
 				D40E041B1F46E3B30043BC4E /* SuperfluousDisableCommandRule.swift */,
+				C225E844252E8B1B00EDE3E7 /* TestCaseAccessibilityRule.swift */,
+				C225E845252E8B1E00EDE3E7 /* TestCaseAccessibilityRuleExamples.swift */,
 				E88DEA811B0990A700A66CB0 /* TodoRule.swift */,
 				D47421F324E14760009AE788 /* UnneededNotificationCenterRemovalRule.swift */,
 				7565E5F02262BA0900B0597C /* UnusedCaptureListRule.swift */,
@@ -2080,6 +2092,7 @@
 				D4F10614229A2F5E00FDE319 /* NoFallthroughOnlyRuleExamples.swift in Sources */,
 				3ABE19CF20B7CE32009C2EC2 /* MultilineFunctionChainsRule.swift in Sources */,
 				82FE253F20F604AD00295958 /* VerticalWhitespaceOpeningBracesRule.swift in Sources */,
+				C26522A2252E93AC00BF9C0C /* TestCaseAccessibilityConfiguration.swift in Sources */,
 				827169B51F48D712003FB9AF /* NoGroupingExtensionRule.swift in Sources */,
 				D41B57781ED8CEE0007B0470 /* ExtensionAccessModifierRule.swift in Sources */,
 				E881985C1BEA978500333A11 /* TrailingNewlineRule.swift in Sources */,
@@ -2137,6 +2150,7 @@
 				623675B01F960C5C009BE6F3 /* QuickDiscouragedPendingTestRule.swift in Sources */,
 				8F4E30D52519092800EED8CB /* UnusedDeclarationRuleExamples.swift in Sources */,
 				287F8B642230843000BDC504 /* NSLocalizedStringRequireBundleRule.swift in Sources */,
+				C225E847252E8B2200EDE3E7 /* TestCaseAccessibilityRuleExamples.swift in Sources */,
 				D47079AD1DFE2FA700027086 /* EmptyParametersRule.swift in Sources */,
 				E87E4A091BFB9CAE00FCFE46 /* SyntaxKind+SwiftLint.swift in Sources */,
 				3B0B14541C505D6300BE82F7 /* SeverityConfiguration.swift in Sources */,
@@ -2191,6 +2205,7 @@
 				E889D8C71F1D357B00058332 /* Configuration+Merging.swift in Sources */,
 				D44254271DB9C15C00492EA4 /* SyntacticSugarRule.swift in Sources */,
 				D4EA77C81F817FD200C315FB /* UnneededBreakInSwitchRule.swift in Sources */,
+				C225E846252E8B2200EDE3E7 /* TestCaseAccessibilityRule.swift in Sources */,
 				D4D383852145F550000235BD /* StaticOperatorRule.swift in Sources */,
 				CC6D285B2292F0600052B682 /* IndentationWidthConfiguration.swift in Sources */,
 				006204DC1E1E492F00FFFBE1 /* VerticalWhitespaceConfiguration.swift in Sources */,
@@ -2409,6 +2424,7 @@
 				A1A6F3F21EE319ED00A9F9E2 /* ObjectLiteralConfiguration.swift in Sources */,
 				D489B548231233A40090BAA0 /* ContainsOverFilterCountRule.swift in Sources */,
 				D4B0228E1E0CC608007E5297 /* ClassDelegateProtocolRule.swift in Sources */,
+				C225E849252E8B3B00EDE3E7 /* XCTestHelpers.swift in Sources */,
 				D4369C572430830000505BB9 /* ComputedAccessorsOrderRuleExamples.swift in Sources */,
 				E881985F1BEA987C00333A11 /* TypeNameRule.swift in Sources */,
 				D40AD08A1E032F9700F48C30 /* UnusedClosureParameterRule.swift in Sources */,

Tests/LinuxMain.swift

@@ -1450,6 +1450,12 @@ extension SyntacticSugarRuleTests {
     ]
 }
 
+extension TestCaseAccessibilityRuleTests {
+    static var allTests: [(String, (TestCaseAccessibilityRuleTests) -> () throws -> Void)] = [
+        ("testWithDefaultConfiguration", testWithDefaultConfiguration)
+    ]
+}
+
 extension TodoRuleTests {
     static var allTests: [(String, (TodoRuleTests) -> () throws -> Void)] = [
         ("testTodo", testTodo),
@@ -1900,6 +1906,7 @@ XCTMain([
     testCase(SwitchCaseAlignmentRuleTests.allTests),
     testCase(SwitchCaseOnNewlineRuleTests.allTests),
     testCase(SyntacticSugarRuleTests.allTests),
+    testCase(TestCaseAccessibilityRuleTests.allTests),
     testCase(TodoRuleTests.allTests),
     testCase(ToggleBoolRuleTests.allTests),
     testCase(TrailingClosureConfigurationTests.allTests),

Tests/SwiftLintFrameworkTests/AutomaticRuleTests.generated.swift

@@ -708,6 +708,12 @@ class SyntacticSugarRuleTests: XCTestCase {
     }
 }
 
+class TestCaseAccessibilityRuleTests: XCTestCase {
+    func testWithDefaultConfiguration() {
+        verifyRule(TestCaseAccessibilityRule.description)
+    }
+}
+
 class ToggleBoolRuleTests: XCTestCase {
     func testWithDefaultConfiguration() {
         verifyRule(ToggleBoolRule.description)