Add W3C.TraceContext

Author: slashmo

Sources/W3CTraceContext/TraceContext.swift

@@ -10,4 +10,20 @@
 // SPDX-License-Identifier: Apache-2.0
 //
 //===----------------------------------------------------------------------===//
+
 public enum W3C {}
+
+extension W3C {
+    public struct TraceContext: Equatable {
+        public let parent: TraceParent
+
+        public init(parent: TraceParent) {
+            self.parent = parent
+        }
+
+        public init?(parent parentRawValue: String) {
+            guard let parent = TraceParent(rawValue: parentRawValue) else { return nil }
+            self.parent = parent
+        }
+    }
+}

Tests/W3CTraceContextTests/TraceContextTests.swift

@@ -0,0 +1,41 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift W3C Trace Context open source project
+//
+// Copyright (c) 2020 Moritz Lang and the Swift W3C Trace Context project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+import W3CTraceContext
+import XCTest
+
+final class TraceContextTests: XCTestCase {
+    func testInitWithValidRawValues() {
+        let traceParentRawValue = "00-0af7651916cd43dd8448eb211c80319c-b7ad6b7169203331-01"
+
+        guard let traceContext = W3C.TraceContext(parent: traceParentRawValue) else {
+            XCTFail("Could not decode valid trace context")
+            return
+        }
+
+        XCTAssertEqual(
+            traceContext,
+            W3C.TraceContext(
+                parent: W3C.TraceParent(
+                    traceID: "0af7651916cd43dd8448eb211c80319c",
+                    parentID: "b7ad6b7169203331",
+                    traceFlags: "01"
+                )
+            )
+        )
+    }
+
+    func testInitWithInvalidTraceParent() {
+        XCTAssertNil(W3C.TraceContext(parent: "invalid"))
+    }
+}