BridgeJS: Support case enums as imported function parameters and returns

Case enums (enums without raw values or associated values) already bridged
across the export boundary as their Int32 tag, but the TypeScript import path
rejected them with "Enum types are not yet supported in TypeScript imports".
The JS glue already round-trips the tag in both directions, so enable case
enums as imported (@JSFunction) parameters and return values by lowering and
lifting that Int32 tag in the import context, matching the export side.

Adds a CaseEnumImports round-trip test and an EnumCaseImport codegen snapshot.

Author: krodak

Plugins/BridgeJS/Sources/BridgeJSCore/ImportTS.swift

@@ -928,12 +928,7 @@ extension BridgeType {
                 return LoweringParameterInfo(loweredParameters: [("objectId", .i32)])
             }
         case .caseEnum:
-            switch context {
-            case .importTS:
-                throw BridgeJSCoreError("Enum types are not yet supported in TypeScript imports")
-            case .exportSwift:
-                return LoweringParameterInfo(loweredParameters: [("value", .i32)])
-            }
+            return LoweringParameterInfo(loweredParameters: [("value", .i32)])
         case .rawValueEnum(_, let rawType):
             if rawType == .string {
                 return .string
@@ -1011,12 +1006,7 @@ extension BridgeType {
                 return LiftingReturnInfo(valueToLift: .i32)
             }
         case .caseEnum:
-            switch context {
-            case .importTS:
-                throw BridgeJSCoreError("Enum types are not yet supported in TypeScript imports")
-            case .exportSwift:
-                return LiftingReturnInfo(valueToLift: .i32)
-            }
+            return LiftingReturnInfo(valueToLift: .i32)
         case .rawValueEnum(_, let rawType):
             let wasmType = rawType.wasmCoreType ?? .i32
             return LiftingReturnInfo(valueToLift: wasmType)

Plugins/BridgeJS/Tests/BridgeJSToolTests/Inputs/MacroSwift/EnumCaseImport.swift

@@ -0,0 +1,12 @@
+@JS enum Signal {
+    case start
+    case stop
+}
+
+// Case enums (no raw value) bridge as their `Int32` tag as imported-function
+// parameters and return values.
+@JSClass struct SignalControls {
+    @JSFunction func send(_ signal: Signal) throws(JSException)
+    @JSFunction func current() throws(JSException) -> Signal
+    @JSFunction static func roundTrip(_ signal: Signal) throws(JSException) -> Signal
+}

Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/EnumCaseImport.json

@@ -0,0 +1,139 @@
+{
+  "exported" : {
+    "classes" : [
+
+    ],
+    "enums" : [
+      {
+        "cases" : [
+          {
+            "associatedValues" : [
+
+            ],
+            "name" : "start"
+          },
+          {
+            "associatedValues" : [
+
+            ],
+            "name" : "stop"
+          }
+        ],
+        "emitStyle" : "const",
+        "name" : "Signal",
+        "staticMethods" : [
+
+        ],
+        "staticProperties" : [
+
+        ],
+        "swiftCallName" : "Signal",
+        "tsFullPath" : "Signal"
+      }
+    ],
+    "exposeToGlobal" : false,
+    "functions" : [
+
+    ],
+    "protocols" : [
+
+    ],
+    "structs" : [
+
+    ]
+  },
+  "imported" : {
+    "children" : [
+      {
+        "functions" : [
+
+        ],
+        "types" : [
+          {
+            "accessLevel" : "internal",
+            "getters" : [
+
+            ],
+            "methods" : [
+              {
+                "accessLevel" : "internal",
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
+                "name" : "send",
+                "parameters" : [
+                  {
+                    "name" : "signal",
+                    "type" : {
+                      "caseEnum" : {
+                        "_0" : "Signal"
+                      }
+                    }
+                  }
+                ],
+                "returnType" : {
+                  "void" : {
+
+                  }
+                }
+              },
+              {
+                "accessLevel" : "internal",
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
+                "name" : "current",
+                "parameters" : [
+
+                ],
+                "returnType" : {
+                  "caseEnum" : {
+                    "_0" : "Signal"
+                  }
+                }
+              }
+            ],
+            "name" : "SignalControls",
+            "setters" : [
+
+            ],
+            "staticMethods" : [
+              {
+                "accessLevel" : "internal",
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
+                "name" : "roundTrip",
+                "parameters" : [
+                  {
+                    "name" : "signal",
+                    "type" : {
+                      "caseEnum" : {
+                        "_0" : "Signal"
+                      }
+                    }
+                  }
+                ],
+                "returnType" : {
+                  "caseEnum" : {
+                    "_0" : "Signal"
+                  }
+                }
+              }
+            ]
+          }
+        ]
+      }
+    ]
+  },
+  "moduleName" : "TestModule",
+  "usedExternalModules" : [
+
+  ]
+}

Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/EnumCaseImport.swift

@@ -0,0 +1,97 @@
+extension Signal: _BridgedSwiftCaseEnum {
+    @_spi(BridgeJS) @_transparent public consuming func bridgeJSLowerParameter() -> Int32 {
+        return bridgeJSRawValue
+    }
+    @_spi(BridgeJS) @_transparent public static func bridgeJSLiftReturn(_ value: Int32) -> Signal {
+        return bridgeJSLiftParameter(value)
+    }
+    @_spi(BridgeJS) @_transparent public static func bridgeJSLiftParameter(_ value: Int32) -> Signal {
+        return Signal(bridgeJSRawValue: value)!
+    }
+    @_spi(BridgeJS) @_transparent public consuming func bridgeJSLowerReturn() -> Int32 {
+        return bridgeJSLowerParameter()
+    }
+
+    @_spi(BridgeJS) @usableFromInline init?(bridgeJSRawValue: Int32) {
+        switch bridgeJSRawValue {
+        case 0:
+            self = .start
+        case 1:
+            self = .stop
+        default:
+            return nil
+        }
+    }
+
+    @_spi(BridgeJS) @usableFromInline var bridgeJSRawValue: Int32 {
+        switch self {
+        case .start:
+            return 0
+        case .stop:
+            return 1
+        }
+    }
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "TestModule", name: "bjs_SignalControls_roundTrip_static")
+fileprivate func bjs_SignalControls_roundTrip_static_extern(_ signal: Int32) -> Int32
+#else
+fileprivate func bjs_SignalControls_roundTrip_static_extern(_ signal: Int32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_SignalControls_roundTrip_static(_ signal: Int32) -> Int32 {
+    return bjs_SignalControls_roundTrip_static_extern(signal)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "TestModule", name: "bjs_SignalControls_send")
+fileprivate func bjs_SignalControls_send_extern(_ self: Int32, _ signal: Int32) -> Void
+#else
+fileprivate func bjs_SignalControls_send_extern(_ self: Int32, _ signal: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_SignalControls_send(_ self: Int32, _ signal: Int32) -> Void {
+    return bjs_SignalControls_send_extern(self, signal)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "TestModule", name: "bjs_SignalControls_current")
+fileprivate func bjs_SignalControls_current_extern(_ self: Int32) -> Int32
+#else
+fileprivate func bjs_SignalControls_current_extern(_ self: Int32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_SignalControls_current(_ self: Int32) -> Int32 {
+    return bjs_SignalControls_current_extern(self)
+}
+
+func _$SignalControls_roundTrip(_ signal: Signal) throws(JSException) -> Signal {
+    let signalValue = signal.bridgeJSLowerParameter()
+    let ret = bjs_SignalControls_roundTrip_static(signalValue)
+    if let error = _swift_js_take_exception() {
+        throw error
+    }
+    return Signal.bridgeJSLiftReturn(ret)
+}
+
+func _$SignalControls_send(_ self: JSObject, _ signal: Signal) throws(JSException) -> Void {
+    let selfValue = self.bridgeJSLowerParameter()
+    let signalValue = signal.bridgeJSLowerParameter()
+    bjs_SignalControls_send(selfValue, signalValue)
+    if let error = _swift_js_take_exception() {
+        throw error
+    }
+}
+
+func _$SignalControls_current(_ self: JSObject) throws(JSException) -> Signal {
+    let selfValue = self.bridgeJSLowerParameter()
+    let ret = bjs_SignalControls_current(selfValue)
+    if let error = _swift_js_take_exception() {
+        throw error
+    }
+    return Signal.bridgeJSLiftReturn(ret)
+}

Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSLinkTests/EnumCaseImport.d.ts

@@ -0,0 +1,33 @@
+// NOTICE: This is auto-generated code by BridgeJS from JavaScriptKit,
+// DO NOT EDIT.
+//
+// To update this file, just rebuild your project or run
+// `swift package bridge-js`.
+
+export const SignalValues: {
+    readonly Start: 0;
+    readonly Stop: 1;
+};
+export type SignalTag = typeof SignalValues[keyof typeof SignalValues];
+
+export type SignalObject = typeof SignalValues;
+
+export interface SignalControls {
+    send(signal: SignalTag): void;
+    current(): SignalTag;
+}
+export type Exports = {
+    Signal: SignalObject
+}
+export type Imports = {
+    SignalControls: {
+        roundTrip(signal: SignalTag): SignalTag;
+    }
+}
+export function createInstantiator(options: {
+    imports: Imports;
+}, swift: any): Promise<{
+    addImports: (importObject: WebAssembly.Imports) => void;
+    setInstance: (instance: WebAssembly.Instance) => void;
+    createExports: (instance: WebAssembly.Instance) => Exports;
+}>;