feat: add hex string extensions

Author: janndriessen

Sources/BasedUtils/extensions/String.swift

@@ -0,0 +1,27 @@
+//
+//  String.swift
+//
+//
+//  Created by Jann Driessen on 12.06.24.
+//
+
+import Foundation
+
+public extension String {
+
+    func addHexPrefix() -> String {
+        if !self.hasPrefix("0x") {
+            return "0x" + self
+        }
+        return self
+    }
+
+    func removeHexPrefix() -> String {
+        if self.hasPrefix("0x") {
+            let indexStart = self.index(self.startIndex, offsetBy: 2)
+            return String(self[indexStart...])
+        }
+        return self
+    }
+
+}

Tests/BasedUtilsTests/StringExtensionsTests.swift

@@ -0,0 +1,39 @@
+//
+//  StringExtensionsTests.swift
+//  
+//
+//  Created by Jann Driessen on 12.06.24.
+//
+
+import XCTest
+
+@testable import BasedUtils
+
+final class StringExtensionsTests: XCTestCase {
+
+    func testAddHexPrefix() throws {
+        let address = "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"
+        let hash = "d8dA6BF26964aF9D7eEd9e03E53415D37aA96045"
+        let hash2 = "d8dA6B"
+        let result = hash.addHexPrefix()
+        let result2 = hash2.addHexPrefix()
+        let result3 = "".addHexPrefix()
+        let resultAddress = address.addHexPrefix()
+        XCTAssertEqual(result, "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045")
+        XCTAssertEqual(result2, "0xd8dA6B")
+        XCTAssertEqual(result3, "0x")
+        XCTAssertEqual(resultAddress, address, "should not add a prefix if one exists")
+    }
+
+    func testStripHexPrefix() throws {
+        let address = "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"
+        let hex = "0xd8dA6B"
+        let stripped = address.removeHexPrefix()
+        let strippedHex = hex.removeHexPrefix()
+        let result = "d8dA6B".removeHexPrefix()
+        XCTAssertEqual(stripped, "d8dA6BF26964aF9D7eEd9e03E53415D37aA96045")
+        XCTAssertEqual(strippedHex, "d8dA6B")
+        XCTAssertEqual(result, "d8dA6B", "should not remove a prefix if none exists")
+    }
+
+}