fix: Tags -> Anlytics

Tests/ResgenSwiftTests/Analytics/DiffString.swift

@@ -0,0 +1,135 @@
+//
+//  File.swift
+//  
+//
+//  Created by Loris Perret on 06/12/2023.
+//
+
+import Foundation
+
+
+/// Find first differing character between two strings
+///
+/// :param: s1 First String
+/// :param: s2 Second String
+///
+/// :returns: .DifferenceAtIndex(i) or .NoDifference
+public func firstDifferenceBetweenStrings(s1: NSString, s2: NSString) -> FirstDifferenceResult {
+    let len1 = s1.length
+    let len2 = s2.length
+    
+    let lenMin = min(len1, len2)
+    
+    for i in 0..<lenMin {
+        if s1.character(at: i) != s2.character(at: i) {
+            return .DifferenceAtIndex(i)
+        }
+    }
+    
+    if len1 < len2 {
+        return .DifferenceAtIndex(len1)
+    }
+
+    if len2 < len1 {
+        return .DifferenceAtIndex(len2)
+    }
+
+    return .NoDifference
+}
+
+
+/// Create a formatted String representation of difference between strings
+///
+/// :param: s1 First string
+/// :param: s2 Second string
+///
+/// :returns: a string, possibly containing significant whitespace and newlines
+public func prettyFirstDifferenceBetweenStrings(s1: String, s2: String) -> String {
+    let firstDifferenceResult = firstDifferenceBetweenStrings(s1: s1 as NSString, s2: s2 as NSString)
+    return prettyDescriptionOfFirstDifferenceResult(firstDifferenceResult: firstDifferenceResult, s1: s1 as NSString, s2: s2 as NSString) as String
+}
+
+
+/// Create a formatted String representation of a FirstDifferenceResult for two strings
+///
+/// :param: firstDifferenceResult FirstDifferenceResult
+/// :param: s1 First string used in generation of firstDifferenceResult
+/// :param: s2 Second string used in generation of firstDifferenceResult
+///
+/// :returns: a printable string, possibly containing significant whitespace and newlines
+public func prettyDescriptionOfFirstDifferenceResult(firstDifferenceResult: FirstDifferenceResult, s1: NSString, s2: NSString) -> NSString {
+
+    func diffString(index: Int, s1: NSString, s2: NSString) -> NSString {
+        let markerArrow = "\u{2b06}"  // "⬆"
+        let ellipsis    = "\u{2026}"  // "…"
+        /// Given a string and a range, return a string representing that substring.
+        ///
+        /// If the range starts at a position other than 0, an ellipsis
+        /// will be included at the beginning.
+        ///
+        /// If the range ends before the actual end of the string,
+        /// an ellipsis is added at the end.
+        func windowSubstring(s: NSString, range: NSRange) -> String {
+            let validRange = NSMakeRange(range.location, min(range.length, s.length - range.location))
+            let substring = s.substring(with: validRange)
+
+            let prefix = range.location > 0 ? ellipsis : ""
+            let suffix = (s.length - range.location > range.length) ? ellipsis : ""
+
+            return "\(prefix)\(substring)\(suffix)"
+        }
+
+        // Show this many characters before and after the first difference
+        let windowPrefixLength = 10
+        let windowSuffixLength = 10
+        let windowLength = windowPrefixLength + 1 + windowSuffixLength
+
+        let windowIndex = max(index - windowPrefixLength, 0)
+        let windowRange = NSMakeRange(windowIndex, windowLength)
+
+        let sub1 = windowSubstring(s: s1, range: windowRange)
+        let sub2 = windowSubstring(s: s2, range: windowRange)
+
+        let markerPosition = min(windowSuffixLength, index) + (windowIndex > 0 ? 1 : 0)
+
+        let markerPrefix = String(repeating: " " as Character, count: markerPosition)
+        let markerLine = "\(markerPrefix)\(markerArrow)"
+
+        return "Difference at index \(index):\n\(sub1)\n\(sub2)\n\(markerLine)" as NSString
+    }
+
+    switch firstDifferenceResult {
+    case .NoDifference:                 return "No difference"
+    case .DifferenceAtIndex(let index): return diffString(index: index, s1: s1, s2: s2)
+    }
+}
+
+
+/// Result type for firstDifferenceBetweenStrings()
+public enum FirstDifferenceResult {
+    /// Strings are identical
+    case NoDifference
+
+    /// Strings differ at the specified index.
+    ///
+    /// This could mean that characters at the specified index are different,
+    /// or that one string is longer than the other
+    case DifferenceAtIndex(Int)
+}
+
+extension FirstDifferenceResult {
+    /// Textual representation of a FirstDifferenceResult
+    public var description: String {
+        switch self {
+        case .NoDifference:
+            return "NoDifference"
+        case .DifferenceAtIndex(let index):
+            return "DifferenceAtIndex(\(index))"
+        }
+    }
+
+    /// Textual representation of a FirstDifferenceResult for debugging purposes
+    public var debugDescription: String {
+        return self.description
+    }
+}