From 0aa9050cb228eaa8d2e09be1457a1dec003fb43b Mon Sep 17 00:00:00 2001
From: Thomas Mellenthin <thomas.mellenthin@teufel.de>
Date: Thu, 9 Mar 2023 17:06:58 +0100
Subject: [PATCH] TypePathConvertible: add a simple type path extension (#46)

---
 .../Utils/TypePathConvertible.swift           | 24 +++++++++++++++
 .../TypePathConvertibleTests.swift            | 30 +++++++++++++++++++
 2 files changed, 54 insertions(+)
 create mode 100644 Sources/FoundationExtensions/Utils/TypePathConvertible.swift
 create mode 100644 Tests/FoundationExtensionsTests/TypePathConvertibleTests.swift

diff --git a/Sources/FoundationExtensions/Utils/TypePathConvertible.swift b/Sources/FoundationExtensions/Utils/TypePathConvertible.swift
new file mode 100644
index 0000000..c5eba9b
--- /dev/null
+++ b/Sources/FoundationExtensions/Utils/TypePathConvertible.swift
@@ -0,0 +1,24 @@
+// Copyright © 2023 Lautsprecher Teufel GmbH. All rights reserved.
+
+import Foundation
+
+/// Allows to turn the Type-hierarchy into a string, i.e. "`Superclass.Subclass`".
+public protocol TypePathConvertible {
+    var typePath: String { get }
+}
+
+extension TypePathConvertible {
+    public var typePath: String {
+        let reflectionString = String(reflecting: self)
+
+        // Regex: "\.\([^\)]*\)" matches .("anything but a closing brace")
+        guard let regex = try? NSRegularExpression(pattern: "\\.\\([^\\)]*\\)", options: NSRegularExpression.Options.caseInsensitive) else {
+            return String(describing: self)
+        }
+        // Remove anonymous types that appear in unit testing, i.e. "A.B.C.(unknown context at $1071608c4).(unknown context at $107160918).yak"
+        return regex.stringByReplacingMatches(in: reflectionString,
+                                              options: [],
+                                              range: NSMakeRange(0, reflectionString.count),
+                                              withTemplate: "")
+    }
+}
diff --git a/Tests/FoundationExtensionsTests/TypePathConvertibleTests.swift b/Tests/FoundationExtensionsTests/TypePathConvertibleTests.swift
new file mode 100644
index 0000000..33e9fca
--- /dev/null
+++ b/Tests/FoundationExtensionsTests/TypePathConvertibleTests.swift
@@ -0,0 +1,30 @@
+// Copyright © 2023 Lautsprecher Teufel GmbH. All rights reserved.
+
+import Foundation
+import FoundationExtensions
+import XCTest
+
+class TypePathConvertibleTests: XCTestCase {
+
+    func testTypePath() {
+        // given
+        enum A: TypePathConvertible {
+            enum B: TypePathConvertible {
+                case foo
+                case bar
+
+                enum C: TypePathConvertible {
+                    case yik
+                    case yak
+                }
+            }
+        }
+        let sut = A.B.C.yak
+
+        // when
+        let result = sut.typePath
+
+        // then
+        XCTAssertEqual(result, "FoundationExtensionsTests.TypePathConvertibleTests.A.B.C.yak")
+    }
+}