Dactyloidae iOS initial commit

mobile/ios/SharedTests/NSMutableAttributedStringExtensionsTests.swift

@@ -0,0 +1,49 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+import UIKit
+import XCTest
+@testable import Shared
+
+class NSMutableAttributedStringExtensionsTests: XCTestCase {
+    fileprivate func checkCharacterAtPosition(_ position: Int, isColored color: UIColor, inString string: NSAttributedString) -> Bool {
+        let attributes = string.attributes(at: position, effectiveRange: nil)
+        if let foregroundColor = attributes[NSForegroundColorAttributeName] as? UIColor {
+            if foregroundColor == color {
+                return true
+            }
+        }
+        return false
+    }
+
+    func testColorsSubstring() {
+        let substring = "bc"
+        let example = NSMutableAttributedString(string: "abcd")
+        example.colorSubstring(substring, withColor: UIColor.red)
+
+        XCTAssertFalse(checkCharacterAtPosition(0, isColored: UIColor.red, inString: example))
+        for position in 1..<3 {
+            XCTAssertTrue(checkCharacterAtPosition(position, isColored: UIColor.red, inString: example))
+        }
+        XCTAssertFalse(checkCharacterAtPosition(3, isColored: UIColor.red, inString: example))
+    }
+
+    func testDoesNothingWithEmptySubstring() {
+        let substring = ""
+        let example = NSMutableAttributedString(string: "abcd")
+        example.colorSubstring(substring, withColor: UIColor.red)
+        for position in 0..<example.string.characters.count {
+            XCTAssertFalse(checkCharacterAtPosition(position, isColored: UIColor.red, inString: example))
+        }
+    }
+
+    func testDoesNothingWhenSubstringNotFound() {
+        let substring = "yyz"
+        let example = NSMutableAttributedString(string: "abcd")
+        example.colorSubstring(substring, withColor: UIColor.red)
+        for position in 0..<example.string.characters.count {
+            XCTAssertFalse(checkCharacterAtPosition(position, isColored: UIColor.red, inString: example))
+        }
+    }
+}