Improve UIView edge constraints methods (#339)

* Improve `UIView` edge constraints methods

* Remove line breaks

Author: tinder-cfuller

Sources/Layout/UIKit/UIView+AutoLayout.swift

@@ -304,7 +304,7 @@ extension UIView {
 
     // MARK: - Edges
 
-    /// Creates constraints to the edges of the superview of the receiver with an inset.
+    /// Creates constraints aligning the edges of the receiver to the edges of the superview with an inset.
     ///
     /// - Parameter inset: The inset value.
     ///
@@ -315,7 +315,8 @@ extension UIView {
         edgeConstraints(insets: UIEdgeInsets(top: inset, left: inset, bottom: inset, right: inset))
     }
 
-    /// Creates constraints to the directional edges of the superview of the receiver with insets.
+    /// Creates constraints aligning the edges of the receiver to the edges of the superview with directional insets
+    /// ([`NSDirectionalEdgeInsets`](https://developer.apple.com/documentation/uikit/nsdirectionaledgeinsets)).
     ///
     /// - Parameter insets: The directional insets.
     ///
@@ -331,7 +332,8 @@ extension UIView {
         ]
     }
 
-    /// Creates constraints to the canonical edges of the superview of the receiver with insets.
+    /// Creates constraints aligning the edges of the receiver to the edges of the superview with canonical insets
+    /// ([`UIEdgeInsets`](https://developer.apple.com/documentation/uikit/uiedgeinsets)).
     ///
     /// - Parameter insets: The canonical insets.
     ///
@@ -346,4 +348,19 @@ extension UIView {
             constraint(toSuperview: .bottom, constant: -insets.bottom)
         ]
     }
+
+    /// Creates constraints aligning the left and right edges of the receiver to the corresponding edges of the
+    /// superview with an inset.
+    ///
+    /// - Parameter inset: The inset value.
+    ///
+    /// - Returns: The created constraints.
+    public func sideEdgeConstraints(
+        inset: CGFloat = 0
+    ) -> [NSLayoutConstraint] {
+        [
+            constraint(toSuperview: .left, constant: inset),
+            constraint(toSuperview: .right, constant: -inset)
+        ]
+    }
 }

Tests/LayoutTests/UIKit/UIView+AutoLayoutTests.swift

@@ -912,4 +912,67 @@ final class UIViewAutoLayoutTests: XCTestCase {
                                                            multiplier: 1,
                                                            constant: -insets.bottom)))
     }
+
+    func testSideEdgeConstraintsInset() {
+
+        // GIVEN
+
+        let superview: UIView = .init()
+        let view: UIView = .init()
+        superview.addSubview(view)
+
+        // WHEN
+
+        let constraints: [NSLayoutConstraint] = view.sideEdgeConstraints()
+
+        // THEN
+
+        expect(constraints.count) == 2
+        expect(constraints[0]).to(match(NSLayoutConstraint(item: view,
+                                                           attribute: .left,
+                                                           relatedBy: .equal,
+                                                           toItem: superview,
+                                                           attribute: .left,
+                                                           multiplier: 1,
+                                                           constant: 0)))
+        expect(constraints[1]).to(match(NSLayoutConstraint(item: view,
+                                                           attribute: .right,
+                                                           relatedBy: .equal,
+                                                           toItem: superview,
+                                                           attribute: .right,
+                                                           multiplier: 1,
+                                                           constant: 0)))
+    }
+
+    func testSideEdgeConstraintsInset_givenInset() {
+
+        // GIVEN
+
+        let superview: UIView = .init()
+        let view: UIView = .init()
+        superview.addSubview(view)
+        let inset: CGFloat = 10
+
+        // WHEN
+
+        let constraints: [NSLayoutConstraint] = view.sideEdgeConstraints(inset: inset)
+
+        // THEN
+
+        expect(constraints.count) == 2
+        expect(constraints[0]).to(match(NSLayoutConstraint(item: view,
+                                                           attribute: .left,
+                                                           relatedBy: .equal,
+                                                           toItem: superview,
+                                                           attribute: .left,
+                                                           multiplier: 1,
+                                                           constant: inset)))
+        expect(constraints[1]).to(match(NSLayoutConstraint(item: view,
+                                                           attribute: .right,
+                                                           relatedBy: .equal,
+                                                           toItem: superview,
+                                                           attribute: .right,
+                                                           multiplier: 1,
+                                                           constant: -inset)))
+    }
 }

cheatsheet.html

@@ -333,6 +333,8 @@ <h3>Edges</h3>
                         <pre>edgeConstraints(inset: 100)</pre>
                         <pre>edgeConstraints(insets: directional)</pre>
                         <pre>edgeConstraints(insets: canonical)</pre>
+                        <pre>sideEdgeConstraints()</pre>
+                        <pre>sideEdgeConstraints(inset: 100)</pre>
                         <h2>Auto Layout</h2>
                         <h3>NSLayoutConstraint</h3>
                         <pre>activate()</pre>