Merge pull request #47 from swiftwasm/jserror

Add JSError with tests, add JSObject.description

Author: kateinoigakukun

IntegrationTests/TestSuites/Sources/PrimaryTests/main.swift

@@ -394,3 +394,11 @@ try test("TypedArray_Mutation") {
     }
     try expectEqual(toString(array.jsValue().object!), jsStringify(Array(0..<100)))
 }
+
+try test("Error") {
+    let message = "test error"
+    let error = JSError(message: message)
+    try expectEqual(error.name, "Error")
+    try expectEqual(error.message, message)
+    try expectEqual(error.description, "Error: test error")
+}

Sources/JavaScriptKit/BasicObjects/JSError.swift

@@ -0,0 +1,20 @@
+public final class JSError {
+    private let ref: JSObject
+    private static let constructor = JSObject.global.Error.function!
+
+    public init(message: String) {
+        ref = Self.constructor.new([message])
+    }
+
+    public var message: String {
+        ref.message.string!
+    }
+
+    public var name: String {
+        ref.name.string!
+    }
+}
+
+extension JSError: CustomStringConvertible {
+    public var description: String { ref.description }
+}

Sources/JavaScriptKit/FundamentalObjects/JSObject.swift

@@ -48,3 +48,6 @@ public class JSObject: Equatable {
     }
 }
 
+extension JSObject: CustomStringConvertible {
+    public var description: String { self.toString!().string! }
+}