Fix issue where setting attributedText could override properties (#10)

* Fix issue where setting attributedText could override properties

There was a regression in 0.0.5 that caused properties that were set on
the label to overwrite the properties of the attributedString the user
was setting on attributedText. This fixes that regression by reverting
the changes that were made to the didSet block of attributedText. Since
there's a valid use-case for wanting to set properties on the label
and have them overwrite the properties inside the attributedstring, I've
added another function `setAttributedText(_ attributedString:
NSAttributedString,
afterInheritingLabelAttributesAndConfiguringWithBlock block:
((NSMutableAttributedString) -> NSMutableAttributedString)?)` to support
that.

* Don't run swiftlint on carthage builds

* Add description for new setAttributedString function

Nantes/Nantes.xcodeproj/project.pbxproj

@@ -211,7 +211,7 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/sh;
-			shellScript = "swift run swiftlint --path .. --strict --quiet\n";
+			shellScript = "if [ -z \"$CARTHAGE\" ]\nthen\n    swift run swiftlint --path .. --strict --quiet\nfi\n";
 		};
 /* End PBXShellScriptBuildPhase section */
 

Nantes/Nantes.xcodeproj/xcshareddata/xcschemes/Nantes.xcscheme

@@ -26,6 +26,7 @@
       buildConfiguration = "Debug"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      codeCoverageEnabled = "YES"
       shouldUseLaunchSchemeArgsEnv = "YES">
       <Testables>
          <TestableReference

Nantes/NantesTests/NantesTests.swift

@@ -151,6 +151,86 @@ final class NantesLabelTests: XCTestCase {
         XCTAssertTrue(size == CGSize(width: 55.0, height: 15.0))
     }
 
+    func testAttributedStringPropertiesStay() {
+        let paragraphStyle = getParagraphStyle()
+        let attributedString = NSAttributedString(string: "Test string with properties", attributes: [.paragraphStyle: paragraphStyle, .kern: 30])
+        addPropertiesToLabel(&label)
+
+        label.attributedText = attributedString
+
+        let updatedParagraphStyle = label.attributedText!.attribute(.paragraphStyle, at: 0, effectiveRange: nil) as! NSParagraphStyle
+        let updatedKern = label.attributedText!.attribute(.kern, at: 0, effectiveRange: nil) as! NSNumber
+
+        XCTAssertEqual(updatedParagraphStyle.lineSpacing, 20)
+        XCTAssertEqual(updatedParagraphStyle.minimumLineHeight, 30)
+        XCTAssertEqual(updatedParagraphStyle.maximumLineHeight, 40)
+        XCTAssertEqual(updatedKern.intValue, 30)
+    }
+
+    func testAttributedStringPropertiesUpdate() {
+        let paragraphStyle = getParagraphStyle()
+        let attributedString = NSAttributedString(string: "Test string with properties", attributes: [.paragraphStyle: paragraphStyle, .kern: 30])
+        addPropertiesToLabel(&label)
+
+        label.setAttributedText(attributedString, afterInheritingLabelAttributesAndConfiguringWithBlock: nil)
+
+        let updatedParagraphStyle = label.attributedText!.attribute(.paragraphStyle, at: 0, effectiveRange: nil) as! NSParagraphStyle
+        let updatedKern = label.attributedText!.attribute(.kern, at: 0, effectiveRange: nil) as! NSNumber
+
+        XCTAssertEqual(updatedParagraphStyle.lineSpacing, 21)
+        XCTAssertEqual(updatedParagraphStyle.minimumLineHeight, 31)
+        XCTAssertEqual(updatedParagraphStyle.maximumLineHeight, 41)
+        XCTAssertEqual(updatedKern.intValue, 31)
+    }
+
+    func testAttributedStringPropertiesUpdateWithBlock() {
+        let paragraphStyle = getParagraphStyle()
+        let attributedString = NSAttributedString(string: "Test string with properties", attributes: [.paragraphStyle: paragraphStyle, .kern: 30])
+        addPropertiesToLabel(&label)
+
+        let promise = expectation(description: "waiting for attributes to be set")
+
+        label.setAttributedText(attributedString) { mutableString -> NSMutableAttributedString in
+            defer {
+                promise.fulfill()
+            }
+            let range = NSRange(location: 0, length: mutableString.length)
+            let paragraphStyle = NSMutableParagraphStyle()
+            paragraphStyle.lineSpacing = 22
+            paragraphStyle.minimumLineHeight = 32
+            paragraphStyle.maximumLineHeight = 42
+
+            mutableString.addAttribute(.paragraphStyle, value: paragraphStyle, range: range)
+            mutableString.addAttribute(.kern, value: 32, range: range)
+            return mutableString
+        }
+
+        XCTWaiter().wait(for: [promise], timeout: 2)
+
+        let updatedParagraphStyle = label.attributedText!.attribute(.paragraphStyle, at: 0, effectiveRange: nil) as! NSParagraphStyle
+        let updatedKern = label.attributedText!.attribute(.kern, at: 0, effectiveRange: nil) as! NSNumber
+
+        XCTAssertEqual(updatedParagraphStyle.lineSpacing, 22)
+        XCTAssertEqual(updatedParagraphStyle.minimumLineHeight, 32)
+        XCTAssertEqual(updatedParagraphStyle.maximumLineHeight, 42)
+        XCTAssertEqual(updatedKern.intValue, 32)
+    }
+
+    private func addPropertiesToLabel(_ label: inout NantesLabel) {
+        label.lineSpacing = 21
+        label.minimumLineHeight = 31
+        label.maximumLineHeight = 41
+        label.kern = 31
+    }
+
+    private func getParagraphStyle() -> NSParagraphStyle {
+        let paragraphStyle = NSMutableParagraphStyle()
+        paragraphStyle.lineSpacing = 20
+        paragraphStyle.minimumLineHeight = 30
+        paragraphStyle.maximumLineHeight = 40
+        return paragraphStyle
+    }
+
     private func addLink(_ link: NSAttributedString, to label: NantesLabel) {
         let dataDetector = try! NSDataDetector(types: label.enabledTextCheckingTypes.rawValue)
         let result = dataDetector.matches(in: link.string, options: .withTransparentBounds, range: NSRange(location: 0, length: link.length)).first

Source/Classes/NantesLabel.swift

@@ -309,18 +309,11 @@ public extension NSAttributedString.Key {
         get {
             return _attributedText
         } set {
-            let attributes = NSAttributedString.attributes(from: self)
-            guard let updatedText = newValue?.mutableCopy() as? NSMutableAttributedString else {
-                return
-            }
-
-            updatedText.addAttributes(attributes, range: NSRange(location: 0, length: updatedText.length))
-
-            guard updatedText != _attributedText else {
+            guard newValue != _attributedText else {
                 return
             }
 
-            _attributedText = updatedText
+            _attributedText = newValue
             setNeedsFramesetter()
             _accessibilityElements = nil
             linkModels = []
@@ -542,6 +535,24 @@ public extension NSAttributedString.Key {
 
     // MARK: - Public
 
+    /// Use this setter when you want to set attributes on NantesLabel before setting attributedText and have the properties get copied over
+    /// This will overwrite properties set on the attributedString passed in, if they're set on NantesLabel. Use `attributedText` if you want
+    /// to keep the properties inside attributedString
+    ///
+    /// More info:
+    /// Check out the `testAttributedStringPropertiesUpdate` test and `testAttributedStringPropertiesUpdateWithBlock` and compare them against
+    /// `testAttributedStringPropertiesStay` for expected behavior against the functions
+    public func setAttributedText(_ attributedString: NSAttributedString, afterInheritingLabelAttributesAndConfiguringWithBlock block: ((NSMutableAttributedString) -> NSMutableAttributedString)?) {
+        var mutableAttributedString = NSMutableAttributedString(attributedString: attributedString)
+        mutableAttributedString.addAttributes(NSAttributedString.attributes(from: self), range: NSRange(location: 0, length: attributedString.length))
+
+        if let block = block {
+            mutableAttributedString = block(mutableAttributedString)
+        }
+
+        attributedText = mutableAttributedString
+    }
+
     /// Adds a single link
     open func addLink(_ link: NantesLabel.Link) {
         addLinks([link])