Adds Data(hex:) to allow creating Data from hex-Strings (without pref…

…ix) (#35)
teufelaudio · Jul 6, 2022 · 503d411 · 503d411
1 parent 34cba24
commit 503d411
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diff --git a/Sources/FoundationExtensions/Data/Data+Extensions.swift b/Sources/FoundationExtensions/Data/Data+Extensions.swift
@@ -31,6 +31,25 @@ extension Numeric {
     }
 }
 
+extension Data {
+
+    public init?(hex: String) {
+        let length = hex.count / 2
+        var data = Data(capacity: length)
+        for i in 0 ..< length {
+            let j = hex.index(hex.startIndex, offsetBy: i * 2)
+            let k = hex.index(j, offsetBy: 2)
+            let bytes = hex[j..<k]
+            if var byte = UInt8(bytes, radix: 16) {
+                data.append(&byte, count: 1)
+            } else {
+                return nil
+            }
+        }
+        self = data
+    }
+}
+
 extension Data {
 
     public func range(start: Int, length: Int) -> Data {

diff --git a/Tests/FoundationExtensionsTests/Data/DataExtensionsTests.swift b/Tests/FoundationExtensionsTests/Data/DataExtensionsTests.swift
@@ -34,5 +34,14 @@ class DataExtensionsTests: XCTestCase {
         let partialData = fullData.range(start: 4, length: 1)
         XCTAssertEqual(partialData, Data([]))
     }
+
+    func testDataFromHexString() {
+        let sut = Data(hex: "6949efc9cf1a68a772af811bca5250bb744aac7c")!
+        XCTAssertEqual(sut, Data([0x69, 0x49, 0xef, 0xc9,
+                                  0xcf, 0x1a, 0x68, 0xa7,
+                                  0x72, 0xaf, 0x81, 0x1b,
+                                  0xca, 0x52, 0x50, 0xbb,
+                                  0x74, 0x4a, 0xac, 0x7c]))
+    }
 }
 #endif