BREAKING: remove css_sizeThatFits:, replace with new API.

Summary: When I try to use this in practice, I have come to realize that css_sizeThatFits will 99% return to you the constrainedSize that you pass it, thus making it useless. Instead, we replace it with a new API that will tell you the optimal size of the resolved layout. From this we can choose to use that size, or scale it down.

Reviewed By: emilsjolander

Differential Revision: D4191873

fbshipit-source-id: d36a2850448d9d82f97e5ef4c7397778c2a14094

CSSLayoutKit/Tests/CSSLayoutKitTests.m

@@ -0,0 +1,128 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+#import <XCTest/XCTest.h>
+
+#import "UIView+CSSLayout.h"
+
+@interface CSSLayoutKitTests : XCTestCase
+@end
+
+@implementation CSSLayoutKitTests
+
+#ifndef TRAVIS_CI
+
+- (void)testNodesAreDeallocedWithSingleView
+{
+  XCTAssertEqual(0, CSSNodeGetInstanceCount());
+
+  UIView *view = [[UIView alloc] initWithFrame:CGRectZero];
+  [view css_setFlexBasis:1];
+  XCTAssertEqual(1, CSSNodeGetInstanceCount());
+  view = nil;
+
+  XCTAssertEqual(0, CSSNodeGetInstanceCount());
+}
+
+- (void)testNodesAreDeallocedCascade
+{
+  XCTAssertEqual(0, CSSNodeGetInstanceCount());
+
+  UIView *view = [[UIView alloc] initWithFrame:CGRectZero];
+  [view css_setFlexBasis:1];
+
+  for (int i=0; i<10; i++) {
+    UIView *subview = [[UIView alloc] initWithFrame:CGRectZero];
+    [subview css_setFlexBasis:1];
+    [view addSubview:subview];
+  }
+  XCTAssertEqual(11, CSSNodeGetInstanceCount());
+  view = nil;
+
+  XCTAssertEqual(0, CSSNodeGetInstanceCount());
+}
+
+#endif
+
+- (void)testUsesFlexbox
+{
+  UIView *view = [[UIView alloc] initWithFrame:CGRectZero];
+  XCTAssertFalse([view css_usesFlexbox]);
+
+  [view css_setUsesFlexbox:YES];
+  XCTAssertTrue([view css_usesFlexbox]);
+
+  [view css_setUsesFlexbox:NO];
+  XCTAssertFalse([view css_usesFlexbox]);
+}
+
+- (void)testSizeThatFitsAsserts
+{
+  UIView *view = [[UIView alloc] initWithFrame:CGRectZero];
+  dispatch_sync(dispatch_queue_create("com.facebook.CSSLayout.testing", DISPATCH_QUEUE_SERIAL), ^(void){
+    XCTAssertThrows([view css_intrinsicSize]);
+  });
+}
+
+- (void)testSizeThatFitsSmoke
+{
+  UIView *container = [[UIView alloc] initWithFrame:CGRectZero];
+  [container css_setUsesFlexbox:YES];
+  [container css_setFlexDirection:CSSFlexDirectionRow];
+  [container css_setAlignItems:CSSAlignFlexStart];
+
+  UILabel *longTextLabel = [[UILabel alloc] initWithFrame:CGRectZero];
+  longTextLabel.text = @"This is a very very very very very very very very long piece of text.";
+  longTextLabel.lineBreakMode = NSLineBreakByTruncatingTail;
+  longTextLabel.numberOfLines = 1;
+  [longTextLabel css_setUsesFlexbox:YES];
+  [longTextLabel css_setFlexShrink:1];
+  [container addSubview:longTextLabel];
+
+  UIView *textBadgeView = [[UIView alloc] initWithFrame:CGRectZero];
+  [textBadgeView css_setUsesFlexbox:YES];
+  [textBadgeView css_setMargin:3.0 forEdge:CSSEdgeLeft];
+  [textBadgeView css_setWidth:10];
+  [textBadgeView css_setHeight:10];
+  [container addSubview:textBadgeView];
+
+  const CGSize containerSize = [container css_intrinsicSize];
+  XCTAssertTrue(CGSizeEqualToSize(CGSizeMake(514,21), containerSize), @"Size is actually %@", NSStringFromCGSize(containerSize));
+}
+
+- (void)testFrameAndOriginPlacement
+{
+  const CGSize containerSize = CGSizeMake(320, 50);
+
+  UIView *container = [[UIView alloc] initWithFrame:CGRectMake(0, 0, containerSize.width, containerSize.height)];
+  [container css_setUsesFlexbox:YES];
+  [container css_setFlexDirection:CSSFlexDirectionRow];
+
+  for (int i = 0; i < 3; i++) {
+    UIView *subview = [[UIView alloc] initWithFrame:CGRectZero];
+    [subview css_setUsesFlexbox:YES];
+    [subview css_setFlexGrow:1];
+
+    [container addSubview:subview];
+  }
+  [container css_applyLayout];
+
+  XCTAssertFalse(CGRectIntersectsRect([container.subviews objectAtIndex:0].frame, [container.subviews objectAtIndex:1].frame));
+  XCTAssertFalse(CGRectIntersectsRect([container.subviews objectAtIndex:1].frame, [container.subviews objectAtIndex:2].frame));
+  XCTAssertFalse(CGRectIntersectsRect([container.subviews objectAtIndex:0].frame, [container.subviews objectAtIndex:2].frame));
+
+  CGFloat totalWidth = 0;
+  for (UIView *view in container.subviews) {
+    totalWidth += view.bounds.size.width;
+  }
+
+  XCTAssertEqual(containerSize.width, totalWidth, @"The container's width is %.6f, the subviews take up %.6f", containerSize.width, totalWidth);
+}
+
+@end