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Encode enum cases without associated values #158

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705f2d3
fix #157
Amzd Feb 6, 2026
b50f820
fixed an error and added a test
Amzd Feb 7, 2026
c189ae2
add coding test
Amzd Feb 7, 2026
37ec496
Fix unused variable
Amzd Feb 15, 2026
c7faecd
Added test
Amzd Feb 15, 2026
2f0473e
conditional break
Amzd Feb 15, 2026
77f07ff
fix tests for last commit
Amzd Feb 15, 2026
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2 changes: 1 addition & 1 deletion Sources/PluginCore/Variables/Enum/Switcher/AdjacentlyTaggableSwitcher.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -388,7 +388,7 @@ extension InternallyTaggedEnumSwitcher: AdjacentlyTaggableSwitcher {
let switchExpr = self.encodeSwitchExpression(
over: location.selfValue, at: location, from: encoder,
in: context, withDefaultCase: location.hasDefaultCase
) { name in
) { name, _ in
let (variable, _) = identifierVariableAndKey(
name, withType: "_", context: context
)
Expand Down
4 changes: 2 additions & 2 deletions Sources/PluginCore/Variables/Enum/Switcher/ExternallyTaggedEnumSwitcher.swift
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Expand Up @@ -170,9 +170,9 @@ package struct ExternallyTaggedEnumSwitcher: TaggedEnumSwitcherVariable {
let switchExpr = self.encodeSwitchExpression(
over: location.selfValue, at: location, from: contentEncoder,
in: context, withDefaultCase: location.hasDefaultCase
) { name in
) { name, hasContent in
"""
let \(contentEncoder) = \(container).superEncoder(forKey: \(name))
let \(hasContent ? contentEncoder : "_") = \(container).superEncoder(forKey: \(name))
"""
}
if let switchExpr = switchExpr {
Expand Down
12 changes: 6 additions & 6 deletions Sources/PluginCore/Variables/Enum/Switcher/TaggedEnumSwitcherVariable.swift
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Expand Up @@ -117,7 +117,7 @@ extension EnumSwitcherVariable {
from coder: TokenSyntax,
in context: some MacroExpansionContext,
withDefaultCase default: Bool,
preSyntax: (TokenSyntax) -> CodeBlockItemListSyntax
preSyntax: ((TokenSyntax, hasContent: Bool)) -> CodeBlockItemListSyntax
) -> SwitchExprSyntax? {
let cases = location.cases
let allEncodable = cases.allSatisfy { $0.variable.encode ?? true }
Expand All @@ -144,12 +144,12 @@ extension EnumSwitcherVariable {

let generatedCode = generated.code.combined()
SwitchCaseSyntax(label: .case(label)) {
let preSyntax = preSyntax(("\(values.first!)", !generatedCode.isEmpty))
preSyntax
if !generatedCode.isEmpty {
CodeBlockItemListSyntax {
preSyntax("\(values.first!)")
generatedCode
}
} else {
generatedCode
}
if preSyntax.isEmpty && generatedCode.isEmpty {
"break"
}
}
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82 changes: 82 additions & 0 deletions Tests/MetaCodableTests/CodableTests.swift
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Expand Up @@ -561,6 +561,88 @@ struct CodableTests {
)
}
}

struct EnumWithoutAssociatedVariables {
@Codable
enum Foo {
case foo
}

@Test
func expansion() throws {
assertMacroExpansion(
"""
@Codable
enum Foo {
case foo
}
""",
expandedSource:
"""
enum Foo {
case foo
}

extension Foo: Decodable {
init(from decoder: any Decoder) throws {
let container = try decoder.container(keyedBy: DecodingKeys.self)
guard container.allKeys.count == 1 else {
let context = DecodingError.Context(
codingPath: container.codingPath,
debugDescription: "Invalid number of keys found, expected one."
)
throw DecodingError.typeMismatch(Self.self, context)
}
let contentDecoder = try container.superDecoder(forKey: container.allKeys.first.unsafelyUnwrapped)
switch container.allKeys.first.unsafelyUnwrapped {
case DecodingKeys.foo:
self = .foo
}
}
}

extension Foo: Encodable {
func encode(to encoder: any Encoder) throws {
var container = encoder.container(keyedBy: CodingKeys.self)
switch self {
case .foo:
let _ = container.superEncoder(forKey: CodingKeys.foo)
}
}
}

extension Foo {
enum CodingKeys: String, CodingKey {
case foo = "foo"
}
enum DecodingKeys: String, CodingKey {
case foo = "foo"
}
}
"""
)
}

@Test
func decodingFromJSON() throws {
let jsonStr = """
{
"foo": {}
}
"""
let jsonData = try #require(jsonStr.data(using: .utf8))
let decoded = try JSONDecoder().decode(Foo.self, from: jsonData)
#expect(decoded == Foo.foo)
}

@Test
func encodingToJSON() throws {
let original = Foo.foo
let encoded = try JSONEncoder().encode(original)
let json = try JSONSerialization.jsonObject(with: encoded) as? [String: Any]
#expect((json?["foo"] as? [String: Any])?.isEmpty == true)
}
}
}

#if canImport(MacroPlugin)
Expand Down
98 changes: 98 additions & 0 deletions Tests/MetaCodableTests/CodedAt/CodedAtEnumTests.swift
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Expand Up @@ -802,4 +802,102 @@ struct CodedAtEnumTests {
#expect(json["int"] as? Int == 42)
}
}

struct WithoutAssociatedVariables {
@Codable
@CodedAt("type")
enum Foo {
case foo
}

@Test
func expansion() throws {
assertMacroExpansion(
"""
@Codable
@CodedAt("type")
enum Foo {
case foo
}
""",
expandedSource:
"""
enum Foo {
case foo
}

extension Foo: Decodable {
init(from decoder: any Decoder) throws {
var typeContainer: KeyedDecodingContainer<CodingKeys>?
let container = try? decoder.container(keyedBy: CodingKeys.self)
if let container = container {
typeContainer = container
} else {
typeContainer = nil
}
if let typeContainer = typeContainer {
let typeString: String?
do {
typeString = try typeContainer.decodeIfPresent(String.self, forKey: CodingKeys.type) ?? nil
} catch {
typeString = nil
}
if let typeString = typeString {
switch typeString {
case "foo":
self = .foo
return
default:
break
}
}
}
let context = DecodingError.Context(
codingPath: decoder.codingPath,
debugDescription: "Couldn't match any cases."
)
throw DecodingError.typeMismatch(Self.self, context)
}
}

extension Foo: Encodable {
func encode(to encoder: any Encoder) throws {
let container = encoder.container(keyedBy: CodingKeys.self)
var typeContainer = container
switch self {
case .foo:
try typeContainer.encode("foo", forKey: CodingKeys.type)
}
}
}

extension Foo {
enum CodingKeys: String, CodingKey {
case type = "type"
}
}
"""
)
}

@Test
func decodingFromJSON() throws {
let jsonStr = """
{
"type": "foo"
}
"""
let jsonData = try #require(jsonStr.data(using: .utf8))
let decoded = try JSONDecoder().decode(Foo.self, from: jsonData)
#expect(decoded == Foo.foo)
}

@Test
func encodingToJSON() throws {
let original = Foo.foo
let encoded = try JSONEncoder().encode(original)
let json = try JSONSerialization.jsonObject(with: encoded) as? [String: Any]
#expect(json?["type"] as? String == "foo")
}
}
}