Update swift-syntax, fix Bool switch warnings, and improve test organization & coverage

.github/workflows/swift.yml

@@ -0,0 +1,42 @@
+# This workflow will build a Swift project
+# For more information see: https://docs.github.com/en/actions/automating-builds-and-tests/building-and-testing-swift
+
+name: Swift `build` & `test`
+
+permissions:
+  contents: read
+
+on:
+  push:
+    branches: [ "main" ]
+    paths-ignore:
+      - '**/*.md'
+  pull_request:
+    paths-ignore:
+      - '**/*.md'
+
+jobs:
+  build-and-test:
+    runs-on: macos-latest
+    timeout-minutes: 20
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v5
+
+      - name: Show Swift version
+        run: swift --version
+
+      - name: Cache SwiftPM dependencies
+        uses: actions/cache@v4
+        with:
+          path: .build
+          key: ${{ runner.os }}-swiftpm-${{ hashFiles('Package.resolved') }}
+          restore-keys: |
+            ${{ runner.os }}-swiftpm-
+
+      - name: Build
+        run: swift build --configuration debug
+
+      - name: Run tests
+        run: swift test --configuration debug --parallel --verbose

.gitignore

@@ -59,6 +59,7 @@ Package.resolved
 *.o
 *.d
 *.swiftdeps*
+*.dia
 
 # CocoaPods
 #

.markdownlint.json

@@ -0,0 +1,11 @@
+{
+  "default": true,
+  "MD012": false,
+  "MD013": false,
+  "MD024": {
+    "siblings_only": true
+  },
+  "MD033": false,
+  "MD041": false,
+  "MD060": false
+}

Package.swift

@@ -35,6 +35,7 @@ let package = Package(
                 .product(name: "SwiftDiagnostics", package: "swift-syntax"),
                 .product(name: "SwiftSyntaxBuilder", package: "swift-syntax"),
                 .product(name: "SwiftSyntaxMacros", package: "swift-syntax"),
+                .product(name: "SwiftSyntaxMacroExpansion", package: "swift-syntax"),
                 .product(name: "OrderedCollections", package: "swift-collections"),
             ]
         ),

Package@swift-5.swift

@@ -34,6 +34,7 @@ let package = Package(
                 .product(name: "SwiftDiagnostics", package: "swift-syntax"),
                 .product(name: "SwiftSyntaxBuilder", package: "swift-syntax"),
                 .product(name: "SwiftSyntaxMacros", package: "swift-syntax"),
+                .product(name: "SwiftSyntaxMacroExpansion", package: "swift-syntax"),
                 .product(name: "OrderedCollections", package: "swift-collections"),
             ]
         ),

README.md

@@ -1,5 +1,6 @@
 # MetaCodable
 
+[![Swift `build` & `test`](https://github.com/qizh/MetaCodable/actions/workflows/swift.yml/badge.svg?branch=tests%2Fimprove%2Fcoverage%2F30-01-26)](https://github.com/qizh/MetaCodable/actions/workflows/swift.yml)
 [![API Docs](http://img.shields.io/badge/Read_the-docs-2196f3.svg)](https://swiftpackageindex.com/SwiftyLab/MetaCodable/documentation/metacodable)
 [![Swift Package Manager Compatible](https://img.shields.io/github/v/tag/SwiftyLab/MetaCodable?label=SPM&color=orange)](https://badge.fury.io/gh/SwiftyLab%2FMetaCodable)
 [![CocoaPods Compatible](https://img.shields.io/cocoapods/v/MetaCodable.svg?label=CocoaPods&color=C90005)](https://badge.fury.io/co/MetaCodable)

Sources/PluginCore/Variables/Enum/Switcher/TaggedEnumSwitcherVariable.swift

@@ -11,23 +11,34 @@ import SwiftSyntaxMacros
 protocol TaggedEnumSwitcherVariable: EnumSwitcherVariable {}
 
 extension TaggedEnumSwitcherVariable {
-    /// Provides the switch expression for decoding.
+    /// Provides a `switch` expression used to decode a tagged enum variable.
     ///
-    /// Based on enum-cases the each case for switch expression is generated.
-    /// Final expression generated combining all cases with provided parameters.
+    /// Generates a `switch` over `header` by mapping each eligible enum case in `location`
+    /// to a corresponding `case` clause. Each generated clause runs `preSyntax` for the
+    /// matched tag value and then emits the decoding code for that enum case.
     ///
     /// - Parameters:
-    ///   - header: The switch header cases are compared to.
-    ///   - location: The decoding location.
-    ///   - coder: The decoder for cases.
-    ///   - context: The context in which to perform the macro expansion.
-    ///   - default: Whether default case is needed.
-    ///   - forceDecodingReturn: Whether to force explicit `return` statements in each
-    ///     switch case. When `true`, adds a `return` statement after the case assignment
-    ///     for early exit. Defaults to `false` for backward compatibility.
-    ///   - preSyntax: The callback to generate case variation data.
+    ///   - header: The expression whose value is matched by the `switch`.
+    ///   - location: The decoding location containing tagged enum cases.
+    ///   - coder: The decoder token used by generated decoding code.
+    ///   - context: The macro expansion context.
+    ///   - default: Whether to include a `default` case.
+    ///   - forceDecodingReturn:
+    ///     - When `true`, emits an explicit `return` after each `case` assignment
+    ///       for early exit.
+    ///     - Defaults to `false` for backward compatibility.
+    ///   - preSyntax: A callback used to generate case-variation syntax for the matched
+    ///     tag value.
     ///
-    /// - Returns: The generated switch expression.
+    /// - Important: For `Bool` tags, the `default` case is omitted only when both `true`
+    ///   and `false` are explicitly covered. With partial coverage (only one of the two
+    ///   values), the `default` case is retained.
+    ///
+    /// - Returns: A `SwitchExprSyntax` when at least one matching switch case can be
+    ///   generated; otherwise `nil`.
+    ///
+    /// - Complexity: `O(𝑛)` in the number of tagged cases in `location`.
+    ///   - Plus the number of tag expressions scanned for `Bool` coverage.
     func decodeSwitchExpression(
         over header: EnumVariable.CaseValue.Expr,
         at location: EnumSwitcherLocation,
@@ -38,6 +49,25 @@ extension TaggedEnumSwitcherVariable {
         preSyntax: (TokenSyntax) -> CodeBlockItemListSyntax
     ) -> SwitchExprSyntax? {
         var switchable = false
+
+        // For Bool type, check if both true and false values are present
+        var hasBoolTrue = false
+        var hasBoolFalse = false
+        if header.type == .bool {
+            for (_, value) in location.cases {
+                let boolValues = value.decodeExprs.filter { $0.type == .bool }
+                for boolValue in boolValues {
+                    let valueStr = boolValue.syntax.trimmedDescription
+                    if valueStr == "true" {
+                        hasBoolTrue = true
+                    } else if valueStr == "false" {
+                        hasBoolFalse = true
+                    }
+                }
+            }
+        }
+        let skipDefaultForBool = header.type == .bool && hasBoolTrue && hasBoolFalse
+
         let switchExpr = SwitchExprSyntax(subject: header.syntax) {
             for (`case`, value) in location.cases where `case`.decode ?? true {
                 let values = value.decodeExprs
@@ -60,7 +90,7 @@ extension TaggedEnumSwitcherVariable {
                 }
             }
 
-            if `default` {
+            if `default` && !skipDefaultForBool {
                 SwitchCaseSyntax(label: .default(.init())) {
                     "break"
                 }

Sources/PluginCore/Variables/Type/EnumVariable.swift

@@ -84,15 +84,19 @@ package struct EnumVariable: TypeVariable, DeclaredVariable {
         let caseEncodeExpr: CaseCode = { name, variables in
             let args = Self.encodingArgs(representing: variables)
             let callee: ExprSyntax = ".\(name)"
-            let fExpr =
-                if !args.isEmpty {
-                    FunctionCallExprSyntax(callee: callee) { args }
-                } else {
-                    FunctionCallExprSyntax(
-                        calledExpression: callee, leftParen: nil, rightParen: nil
-                    ) {}
-                }
-            return ExprSyntax(fExpr)
+            if args.isEmpty {
+                /// No associated values: return just the case name without parentheses
+                return callee
+            } else {
+                let fExpr = FunctionCallExprSyntax(
+                    calledExpression: callee,
+                    leftParen: .leftParenToken(),
+                    arguments: args,
+                    rightParen: .rightParenToken(),
+                    trailingClosure: nil
+                )
+                return ExprSyntax(fExpr)
+            }
         }
         self.init(
             from: decl, in: context,

Tests/MetaCodableTests/AccessModifierTests.swift

@@ -4,14 +4,16 @@ import Testing
 
 @testable import PluginCore
 
+@Suite("Access Modifier Tests")
 struct AccessModifierTests {
+    @Suite("Access Modifier - Open")
     struct Open {
         @Codable
         open class SomeCodable {
             let value: String
         }
 
-        @Test
+        @Test("Generates @Codable conformance for class with 'open' access", .tags(.accessModifiers, .classes, .codable, .decoding, .encoding, .enums, .macroExpansion))
         func expansion() throws {
             assertMacroExpansion(
                 """
@@ -49,7 +51,7 @@ struct AccessModifierTests {
             )
         }
 
-        @Test
+        @Test("Decodes class from JSON successfully", .tags(.accessModifiers, .classes, .decoding))
         func openClassDecodingOnly() throws {
             // Open class doesn't have memberwise init, only decoder init
             let jsonStr = """
@@ -63,7 +65,7 @@ struct AccessModifierTests {
             #expect(decoded.value == "open_test")
         }
 
-        @Test
+        @Test("Decodes from JSON successfully", .tags(.accessModifiers, .decoding))
         func openClassFromJSON() throws {
             let jsonStr = """
                 {
@@ -77,14 +79,15 @@ struct AccessModifierTests {
         }
     }
 
+    @Suite("Access Modifier - Public")
     struct Public {
         @Codable
         @MemberInit
         public struct SomeCodable {
             let value: String
         }
 
-        @Test
+        @Test("Generates macro expansion with @Codable for struct with 'public' access", .tags(.accessModifiers, .codable, .decoding, .encoding, .enums, .macroExpansion, .memberInit, .structs))
         func expansion() throws {
             assertMacroExpansion(
                 """
@@ -127,7 +130,7 @@ struct AccessModifierTests {
             )
         }
 
-        @Test
+        @Test("Encodes and decodes successfully", .tags(.accessModifiers, .decoding, .encoding))
         func publicStructDecodingAndEncoding() throws {
             let original = SomeCodable(value: "public_test")
             let encoded = try JSONEncoder().encode(original)
@@ -136,7 +139,7 @@ struct AccessModifierTests {
             #expect(decoded.value == "public_test")
         }
 
-        @Test
+        @Test("Decodes from JSON successfully (AccessModifierTests #1)", .tags(.accessModifiers, .decoding))
         func publicStructFromJSON() throws {
             let jsonStr = """
                 {
@@ -150,14 +153,15 @@ struct AccessModifierTests {
         }
     }
 
+    @Suite("Access Modifier - Package")
     struct Package {
         @Codable
         @MemberInit
         package struct SomeCodable {
             let value: String
         }
 
-        @Test
+        @Test("Generates macro expansion with @Codable for struct", .tags(.accessModifiers, .codable, .decoding, .encoding, .enums, .macroExpansion, .memberInit, .structs))
         func expansion() throws {
             assertMacroExpansion(
                 """
@@ -201,6 +205,7 @@ struct AccessModifierTests {
         }
     }
 
+    @Suite("Access Modifier - Others")
     struct Others {
         struct Internal {
             @Codable

Tests/MetaCodableTests/Attributes/CodedByTests.swift

@@ -2,8 +2,9 @@ import Testing
 
 @testable import PluginCore
 
+@Suite("Coded By Tests")
 struct CodedByTests {
-    @Test
+    @Test("Reports error for @CodedBy misuse", .tags(.codedBy, .errorHandling, .macroExpansion, .structs))
     func misuseOnNonVariableDeclaration() throws {
         assertMacroExpansion(
             """
@@ -34,7 +35,7 @@ struct CodedByTests {
         )
     }
 
-    @Test
+    @Test("Reports error for @CodedBy misuse (CodedByTests #1)", .tags(.codedBy, .errorHandling, .macroExpansion, .structs))
     func misuseOnStaticVariable() throws {
         assertMacroExpansion(
             """
@@ -63,7 +64,7 @@ struct CodedByTests {
         )
     }
 
-    @Test
+    @Test("Reports error when @CodedBy is applied multiple times", .tags(.codedBy, .errorHandling, .macroExpansion, .structs))
     func duplicatedMisuse() throws {
         assertMacroExpansion(
             """

Tests/MetaCodableTests/Attributes/DefaultTests.swift

@@ -4,8 +4,9 @@ import Testing
 
 @testable import PluginCore
 
+@Suite("Default Tests")
 struct DefaultTests {
-    @Test
+    @Test("Reports error for @Default misuse", .tags(.default, .errorHandling, .macroExpansion, .structs))
     func misuseOnNonVariableDeclaration() throws {
         assertMacroExpansion(
             """
@@ -36,7 +37,7 @@ struct DefaultTests {
         )
     }
 
-    @Test
+    @Test("Reports error for @Default misuse (DefaultTests #1)", .tags(.default, .errorHandling, .macroExpansion, .structs))
     func misuseOnStaticVariable() throws {
         assertMacroExpansion(
             """
@@ -65,7 +66,7 @@ struct DefaultTests {
         )
     }
 
-    @Test
+    @Test("Reports error when @Default is applied multiple times", .tags(.default, .errorHandling, .macroExpansion, .structs))
     func duplicatedMisuse() throws {
         assertMacroExpansion(
             """
@@ -104,6 +105,7 @@ struct DefaultTests {
         )
     }
 
+    @Suite("Default - Default Value Behavior")
     struct DefaultValueBehavior {
         @Codable
         struct SomeCodable {
@@ -113,7 +115,7 @@ struct DefaultTests {
             let number: Int
         }
 
-        @Test
+        @Test("Decodes from JSON successfully (DefaultTests #2)", .tags(.decoding, .default))
         func defaultValueUsage() throws {
             // Test with missing keys in JSON
             let jsonStr = "{}"
@@ -124,7 +126,7 @@ struct DefaultTests {
             #expect(decoded.number == 42)
         }
 
-        @Test
+        @Test("Decodes from JSON successfully (DefaultTests #3)", .tags(.decoding, .default))
         func overrideDefaultValues() throws {
             // Test with provided values in JSON
             let jsonStr = """
@@ -140,7 +142,7 @@ struct DefaultTests {
             #expect(decoded.number == 100)
         }
 
-        @Test
+        @Test("Encodes and decodes successfully (DefaultTests #1)", .tags(.decoding, .default, .encoding))
         func encodingWithDefaults() throws {
             let original = SomeCodable(value: "test", number: 99)
             let encoded = try JSONEncoder().encode(original)