better header comments, weak ref to views!

@@ -79,7 +79,6 @@
 		DD52F1E6179CAACA005CD195 /* UIView+MASAdditions.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = "UIView+MASAdditions.m"; sourceTree = "<group>"; };
 		DD52F1ED179CAAEE005CD195 /* Masonry.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = Masonry.h; sourceTree = "<group>"; };
 		DDE2653D179D24E600D48565 /* UIView+MASShorthandAdditions.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = "UIView+MASShorthandAdditions.h"; sourceTree = "<group>"; };
-		DDF3875D179E8A2900178773 /* SpecHelpers.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SpecHelpers.h; sourceTree = "<group>"; };
 		DE643A835A4447F4807FDBFA /* libPods-MasonryTests.a */ = {isa = PBXFileReference; explicitFileType = archive.ar; includeInIndex = 0; path = "libPods-MasonryTests.a"; sourceTree = BUILT_PRODUCTS_DIR; };
 /* End PBXFileReference section */
 
@@ -179,7 +178,6 @@
 		DD52F1D7179CAA78005CD195 /* Specs */ = {
 			isa = PBXGroup;
 			children = (
-				DDF3875D179E8A2900178773 /* SpecHelpers.h */,
 				DD52F1D8179CAA9C005CD195 /* MASCompositeConstraintSpec.m */,
 				DD52F1D9179CAA9C005CD195 /* MASViewConstraintSpec.m */,
 			);

@@ -10,15 +10,15 @@
 #import "MASConstraint.h"
 
 typedef NS_ENUM(NSInteger, MASCompositeViewConstraintType) {
-    MASCompositeViewConstraintTypeEdges,
-    MASCompositeViewConstraintTypeSize,
-    MASCompositeViewConstraintTypeCenter,
+    MASCompositeViewConstraintTypeEdges, //top, left, bottom, right
+    MASCompositeViewConstraintTypeSize, //width, height
+    MASCompositeViewConstraintTypeCenter, //centerX, centerY
 };
 
 @interface MASCompositeConstraint : NSObject <MASConstraint>
 
 @property (nonatomic, weak) id<MASConstraintDelegate> delegate;
-@property (nonatomic, strong, readonly) UIView *view;
+@property (nonatomic, weak, readonly) UIView *view;
 @property (nonatomic, assign, readonly) MASCompositeViewConstraintType type;
 
 - (id)initWithView:(UIView *)view type:(MASCompositeViewConstraintType)type;

@@ -69,7 +69,7 @@
     [self.completedChildConstraints addObject:constraint];
 }
 
-#pragma mark - layout constant
+#pragma mark - NSLayoutConstraint constant proxies
 
 - (id<MASConstraint> (^)(UIEdgeInsets))insets {
     return ^id(UIEdgeInsets insets) {
@@ -107,7 +107,7 @@
     };
 }
 
-#pragma mark - layout multiplier
+#pragma mark - NSLayoutConstraint multiplier proxies 
 
 - (id<MASConstraint> (^)(CGFloat))percent {
     return ^id(CGFloat percent) {
@@ -118,7 +118,7 @@
     };
 }
 
-#pragma mark - layout priority
+#pragma mark - MASLayoutPriority proxies
 
 - (id<MASConstraint> (^)(MASLayoutPriority))priority {
     return ^id(MASLayoutPriority priority) {
@@ -150,7 +150,7 @@
     };
 }
 
-#pragma mark - layout relation
+#pragma mark - NSLayoutRelation proxies
 
 - (id<MASConstraint> (^)(id))relationWithBlock:(id<MASConstraint> (^)(id<MASConstraint> constraint, id attr))block {
     return ^id(id attr) {
@@ -199,6 +199,8 @@
     for (id<MASConstraint> constraint in self.completedChildConstraints) {
         [constraint commit];
     }
+    [self.currentChildConstraints removeAllObjects];
+    [self.completedChildConstraints removeAllObjects];
 }
 
 @end

@@ -19,22 +19,22 @@ typedef float MASLayoutPriority;
 
 @protocol MASConstraint <NSObject>
 
-//layout constants
+//NSLayoutConstraint constant proxies
 @property (nonatomic, copy, readonly) id<MASConstraint> (^insets)(UIEdgeInsets insets);
 @property (nonatomic, copy, readonly) id<MASConstraint> (^sizeOffset)(CGSize offset);
 @property (nonatomic, copy, readonly) id<MASConstraint> (^centerOffset)(CGPoint offset);
 @property (nonatomic, copy, readonly) id<MASConstraint> (^offset)(CGFloat offset);
 
-//layout multipliers
+//NSLayoutConstraint multiplier proxies
 @property (nonatomic, copy, readonly) id<MASConstraint> (^percent)(CGFloat percent);
 
-//layout priority
-@property (nonatomic, copy, readonly) id<MASConstraint> (^priority)(UILayoutPriority priority);
+//MASLayoutPriority proxies
+@property (nonatomic, copy, readonly) id<MASConstraint> (^priority)(MASLayoutPriority priority);
 @property (nonatomic, copy, readonly) id<MASConstraint> (^priorityLow)();
 @property (nonatomic, copy, readonly) id<MASConstraint> (^priorityMedium)();
 @property (nonatomic, copy, readonly) id<MASConstraint> (^priorityHigh)();
 
-//layout relation
+//NSLayoutRelation proxies
 @property (nonatomic, copy, readonly) id<MASConstraint> (^equalTo)(id attr);
 @property (nonatomic, copy, readonly) id<MASConstraint> (^greaterThanOrEqualTo)(id attr);
 @property (nonatomic, copy, readonly) id<MASConstraint> (^lessThanOrEqualTo)(id attr);
@@ -42,12 +42,18 @@ typedef float MASLayoutPriority;
 //semantic properties
 @property (nonatomic, copy, readonly) id<MASConstraint> with;
 
+/**
+ Creates a NSLayoutConstraint. The constraint is added to the first view or the or the closest common superview of the first and second view. 
+ */
 - (void)commit;
 
 @end
 
 @protocol MASConstraintDelegate <NSObject>
 
+/**
+ Notifies the delegate when the constraint is has the minimum set of properties, has a NSLayoutRelation and view
+ */
 - (void)addConstraint:(id<MASConstraint>)constraint;
 
 @end
\ No newline at end of file

@@ -13,7 +13,7 @@
 
 @interface MASConstraintMaker () <MASConstraintDelegate>
 
-@property (nonatomic, strong) UIView *view;
+@property (nonatomic, weak) UIView *view;
 @property (nonatomic, strong) NSMutableArray *constraints;
 
 @end

@@ -10,11 +10,16 @@
 
 @interface MASViewAttribute : NSObject
 
-@property (nonatomic, strong, readonly) UIView *view;
+@property (nonatomic, weak, readonly) UIView *view;
 @property (nonatomic, assign, readonly) NSLayoutAttribute layoutAttribute;
 
 - (id)initWithView:(UIView *)view layoutAttribute:(NSLayoutAttribute)layoutAttribute;
 
-- (BOOL)isAlignment;
+/**
+ Creates a MASConstraintMaker with the callee view. any constraints defined are added to the view or the appropriate superview once the block has finished executing
+
+ @return YES if layoutAttribute is equal to NSLayoutAttributeWidth or NSLayoutAttributeHeight
+ */
+- (BOOL)isSizeAttribute;
 
 @end

@@ -20,8 +20,8 @@
     return self;
 }
 
-- (BOOL)isAlignment {
-    return self.layoutAttribute != NSLayoutAttributeWidth && self.layoutAttribute != NSLayoutAttributeHeight;
+- (BOOL)isSizeAttribute {
+    return self.layoutAttribute == NSLayoutAttributeWidth || self.layoutAttribute == NSLayoutAttributeHeight;
 }
 
 @end

@@ -61,7 +61,6 @@
     } else {
         NSAssert(YES, @"attempting to add unsupported attribute: %@", secondViewAttribute);
     }
-    [self.delegate addConstraint:self];
 }
 
 - (instancetype)cloneIfNeeded {
@@ -76,7 +75,7 @@
     return self;
 }
 
-#pragma mark - layout constant
+#pragma mark - NSLayoutConstraint constant proxies
 
 - (id<MASConstraint> (^)(UIEdgeInsets))insets {
     return ^id(UIEdgeInsets insets){
@@ -142,7 +141,7 @@
     };
 }
 
-#pragma mark - layout multiplier
+#pragma mark - NSLayoutConstraint multiplier proxies
 
 - (id<MASConstraint> (^)(CGFloat))percent {
     return ^id(CGFloat percent) {
@@ -154,7 +153,7 @@
     };
 }
 
-#pragma mark - layout priority
+#pragma mark - MASLayoutPriority proxies
 
 - (id<MASConstraint> (^)(MASLayoutPriority))priority {
     return ^id(MASLayoutPriority priority) {
@@ -187,7 +186,7 @@
     };
 }
 
-#pragma mark - layout relation
+#pragma mark - NSLayoutRelation proxies
 
 - (id<MASConstraint> (^)(id))equalTo {
     return ^id(id attr) {
@@ -197,6 +196,7 @@
         MASViewConstraint *viewConstraint = [self cloneIfNeeded];
         viewConstraint.layoutRelation = NSLayoutRelationEqual;
         viewConstraint.secondViewAttribute = attr;
+        [viewConstraint.delegate addConstraint:viewConstraint];
         return viewConstraint;
     };
 }
@@ -209,6 +209,7 @@
         MASViewConstraint *viewConstraint = [self cloneIfNeeded];
         viewConstraint.layoutRelation = NSLayoutRelationGreaterThanOrEqual;
         viewConstraint.secondViewAttribute = attr;
+        [viewConstraint.delegate addConstraint:viewConstraint];
         return viewConstraint;
     };
 }
@@ -221,6 +222,7 @@
         MASViewConstraint *viewConstraint = [self cloneIfNeeded];
         viewConstraint.layoutRelation = NSLayoutRelationLessThanOrEqual;
         viewConstraint.secondViewAttribute = attr;
+        [viewConstraint.delegate addConstraint:viewConstraint];
         return viewConstraint;
     };
 }
@@ -240,7 +242,7 @@
     NSLayoutAttribute firstLayoutAttribute = self.firstViewAttribute.layoutAttribute;
     UIView *secondLayoutItem = self.secondViewAttribute.view;
     NSLayoutAttribute secondLayoutAttribute = self.secondViewAttribute.layoutAttribute;
-    if (self.firstViewAttribute.isAlignment && !self.secondViewAttribute) {
+    if (!self.firstViewAttribute.isSizeAttribute && !self.secondViewAttribute) {
         secondLayoutItem = firstLayoutItem.superview;
         secondLayoutAttribute = firstLayoutAttribute;
     }

@@ -12,6 +12,7 @@
 
 @interface UIView (MASAdditions)
 
+// following properties return a new MASViewAttribute with current view and appropriate NSLayoutAttribute
 @property (nonatomic, strong, readonly) MASViewAttribute *mas_left;
 @property (nonatomic, strong, readonly) MASViewAttribute *mas_top;
 @property (nonatomic, strong, readonly) MASViewAttribute *mas_right;
@@ -24,6 +25,11 @@
 @property (nonatomic, strong, readonly) MASViewAttribute *mas_centerY;
 @property (nonatomic, strong, readonly) MASViewAttribute *mas_baseline;
 
+/**
+ Creates a MASConstraintMaker with the callee view. any constraints defined are added to the view or the appropriate superview once the block has finished executing
+
+ @param block scope within which you can build up the constraints which you wish to apply to the view.
+ */
 - (void)mas_makeConstraints:(void(^)(MASConstraintMaker *make))block;
 
 @end
\ No newline at end of file

@@ -17,7 +17,7 @@
     [constraintMaker commit];
 }
 
-#pragma mark - attribute properties
+#pragma mark - NSLayoutAttribute properties
 
 - (MASViewAttribute *)mas_left {
     return [[MASViewAttribute alloc] initWithView:self layoutAttribute:NSLayoutAttributeLeft];

@@ -8,7 +8,6 @@
 
 #import "MASCompositeConstraint.h"
 #import "MASViewConstraint.h"
-#import "SpecHelpers.h"
 
 @interface MASCompositeConstraint () <MASConstraintDelegate>
 
@@ -26,8 +25,22 @@
 
 SpecBegin(MASCompositeConstraint)
 
+__block id<MASConstraintDelegate> delegate;
+__block UIView *superview;
+__block UIView *view;
+__block MASCompositeConstraint *composite;
+
+beforeEach(^{
+    composite = nil;
+    delegate = mockProtocol(@protocol(MASConstraintDelegate));
+    view = UIView.new;
+    superview = UIView.new;
+    [superview addSubview:view];
+});
+
 it(@"should create centerY and centerX children", ^{
-    MASCompositeConstraint *composite = createCompositeWithType(MASCompositeViewConstraintTypeCenter);
+    composite = [[MASCompositeConstraint alloc] initWithView:view type:MASCompositeViewConstraintTypeCenter];
+
     expect(composite.currentChildConstraints).to.haveCountOf(2);
 
     MASViewConstraint *viewConstraint = composite.currentChildConstraints[0];
@@ -41,7 +54,7 @@ it(@"should create centerY and centerX children", ^{
 
 it(@"should create top, left, bottom, right children", ^{
     UIView *newView = UIView.new;
-    MASCompositeConstraint *composite = createCompositeWithType(MASCompositeViewConstraintTypeEdges);
+    composite = [[MASCompositeConstraint alloc] initWithView:view type:MASCompositeViewConstraintTypeEdges];
     composite.equalTo(newView);
 
     expect(composite.completedChildConstraints).to.haveCountOf(4);
@@ -68,7 +81,7 @@ it(@"should create top, left, bottom, right children", ^{
 });
 
 it(@"should create width and height children", ^{
-    MASCompositeConstraint *composite = createCompositeWithType(MASCompositeViewConstraintTypeSize);
+    composite = [[MASCompositeConstraint alloc] initWithView:view type:MASCompositeViewConstraintTypeSize];
     expect(composite.currentChildConstraints).to.haveCountOf(2);
 
     MASViewConstraint *viewConstraint = composite.currentChildConstraints[0];
@@ -81,24 +94,25 @@ it(@"should create width and height children", ^{
 });
 
 it(@"should complete children", ^{
-    UIView *view = UIView.new;
-    MASCompositeConstraint *composite = createCompositeWithType(MASCompositeViewConstraintTypeSize);
+    composite = [[MASCompositeConstraint alloc] initWithView:view type:MASCompositeViewConstraintTypeSize];
+    composite.delegate = delegate;
+    UIView *newView = UIView.new;
 
     //first equality statement
-    composite.equalTo(view).sizeOffset(CGSizeMake(90, 30));
+    composite.equalTo(newView).sizeOffset(CGSizeMake(90, 30));
 
-    [verify(composite.delegate) addConstraint:(id)composite];
+    [verify(delegate) addConstraint:(id)composite];
 
     expect(composite.completedChildConstraints).to.haveCountOf(2);
     expect(composite.currentChildConstraints).to.haveCountOf(2);
 
     MASViewConstraint *viewConstraint = composite.completedChildConstraints[0];
-    expect(viewConstraint.secondViewAttribute.view).to.beIdenticalTo(view);
+    expect(viewConstraint.secondViewAttribute.view).to.beIdenticalTo(newView);
     expect(viewConstraint.secondViewAttribute.layoutAttribute).to.equal(NSLayoutAttributeWidth);
     expect(viewConstraint.layoutConstant).to.equal(90);
 
     viewConstraint = composite.completedChildConstraints[1];
-    expect(viewConstraint.secondViewAttribute.view).to.beIdenticalTo(view);
+    expect(viewConstraint.secondViewAttribute.view).to.beIdenticalTo(newView);
     expect(viewConstraint.secondViewAttribute.layoutAttribute).to.equal(NSLayoutAttributeHeight);
     expect(viewConstraint.layoutConstant).to.equal(30);
 
@@ -127,4 +141,24 @@ it(@"should complete children", ^{
     expect(viewConstraint.firstViewAttribute.layoutAttribute).to.equal(NSLayoutAttributeHeight);
 });
 
+it(@"should remove all on commit", ^{
+    composite = [[MASCompositeConstraint alloc] initWithView:view type:MASCompositeViewConstraintTypeSize];
+    composite.delegate = delegate;
+    UIView *newView = UIView.new;
+    [superview addSubview:newView];
+
+    //first equality statement
+    composite.equalTo(newView).sizeOffset(CGSizeMake(90, 30));
+
+    [verify(delegate) addConstraint:(id)composite];
+
+    expect(composite.completedChildConstraints).to.haveCountOf(2);
+    expect(composite.currentChildConstraints).to.haveCountOf(2);
+
+    [composite commit];
+
+    expect(composite.completedChildConstraints).to.haveCountOf(0);
+    expect(composite.currentChildConstraints).to.haveCountOf(0);
+});
+
 SpecEnd
\ No newline at end of file

@@ -8,7 +8,7 @@
 
 #import "MASViewConstraint.h"
 #import "MASConstraint.h"
-#import "SpecHelpers.h"
+#import "UIView+MASAdditions.h"
 
 @interface MASViewConstraint ()
 
@@ -23,22 +23,30 @@
 
 SpecBegin(MASViewConstraint)
 
+__block id<MASConstraintDelegate> delegate;
 __block UIView *superview;
 __block MASViewConstraint *constraint;
-__block MASViewAttribute *secondViewAttribute;
+__block UIView *otherView;
+
 
 beforeEach(^{
     superview = UIView.new;
-    constraint = createConstraintWithLayoutAttribute(NSLayoutAttributeWidth);
-    [superview addSubview:constraint.firstViewAttribute.view];
+    delegate = mockProtocol(@protocol(MASConstraintDelegate));
+
+    UIView *view = UIView.new;
+    constraint = [[MASViewConstraint alloc] initWithFirstViewAttribute:view.mas_width];
+    constraint.delegate = delegate;
+
+    [superview addSubview:view];
 
-    secondViewAttribute = createViewAttribute(NSLayoutAttributeHeight);
-    [superview addSubview:secondViewAttribute.view];
+    otherView = UIView.new;
+    [superview addSubview:otherView];
 });
 
 describe(@"equality chaining", ^{
     
     it(@"should return same constraint when encountering equal for first time", ^{
+        MASViewAttribute *secondViewAttribute = otherView.mas_top;
         MASViewConstraint *newConstraint = constraint.equalTo(secondViewAttribute);
         
         [verify(constraint.delegate) addConstraint:(id)constraint];
@@ -48,6 +56,7 @@ describe(@"equality chaining", ^{
     });
     
     it(@"should start new constraint when encountering equal subsequently", ^{
+        MASViewAttribute *secondViewAttribute = otherView.mas_top;
         constraint.greaterThanOrEqualTo(secondViewAttribute);
         MASViewConstraint *newConstraint = constraint.equalTo(secondViewAttribute);
         
@@ -57,6 +66,7 @@ describe(@"equality chaining", ^{
     });
     
     it(@"should return same constraint when encountering greaterThanOrEqual for first time", ^{
+        MASViewAttribute *secondViewAttribute = otherView.mas_top;
         MASViewConstraint *newConstraint = constraint.greaterThanOrEqualTo(secondViewAttribute);
         
         [verify(constraint.delegate) addConstraint:(id)constraint];
@@ -66,6 +76,7 @@ describe(@"equality chaining", ^{
     });
     
     it(@"should start new constraint when encountering greaterThanOrEqual subsequently", ^{
+        MASViewAttribute *secondViewAttribute = otherView.mas_top;
         constraint.lessThanOrEqualTo(secondViewAttribute);
         MASViewConstraint *newConstraint = constraint.greaterThanOrEqualTo(secondViewAttribute);
         
@@ -75,6 +86,7 @@ describe(@"equality chaining", ^{
     });
     
     it(@"should return same constraint when encountering lessThanOrEqual for first time", ^{
+        MASViewAttribute *secondViewAttribute = otherView.mas_top;
         MASViewConstraint *newConstraint = constraint.lessThanOrEqualTo(secondViewAttribute);
         
         [verify(constraint.delegate) addConstraint:(id)constraint];
@@ -84,6 +96,7 @@ describe(@"equality chaining", ^{
     });
     
     it(@"should start new constraint when encountering lessThanOrEqual subsequently", ^{
+        MASViewAttribute *secondViewAttribute = otherView.mas_top;
         constraint.equalTo(secondViewAttribute);
         MASViewConstraint *newConstraint = constraint.lessThanOrEqualTo(secondViewAttribute);
         
@@ -93,6 +106,7 @@ describe(@"equality chaining", ^{
     });
     
     it(@"should not allow update of equal once layoutconstraint is created", ^{
+        MASViewAttribute *secondViewAttribute = otherView.mas_top;
         [constraint commit];
         
         expect(^{
@@ -101,6 +115,7 @@ describe(@"equality chaining", ^{
     });
     
     it(@"should not allow update of lessThanOrEqual once layoutconstraint is created", ^{
+        MASViewAttribute *secondViewAttribute = otherView.mas_top;
         [constraint commit];
         
         expect(^{
@@ -109,6 +124,7 @@ describe(@"equality chaining", ^{
     });
     
     it(@"should not allow update of greaterThanOrEqual once layoutconstraint is created", ^{
+        MASViewAttribute *secondViewAttribute = otherView.mas_top;
         [constraint commit];
         
         expect(^{
@@ -123,7 +139,7 @@ describe(@"equality chaining", ^{
         expect(constraint.secondViewAttribute.view).to.beIdenticalTo(view);
         expect(constraint.firstViewAttribute.layoutAttribute).to.equal(constraint.secondViewAttribute.layoutAttribute);
     });
-
+    
     xit(@"should create composite when passed array of views", ^{
 
     });
@@ -148,65 +164,66 @@ describe(@"multiplier & constant", ^{
     });
     
     it(@"should update sides offset only", ^{
-        MASViewConstraint *centerY = createConstraintWithLayoutAttribute(NSLayoutAttributeCenterY);
+        MASViewConstraint *centerY = [[MASViewConstraint alloc] initWithFirstViewAttribute:otherView.mas_centerY];
         centerY.insets(UIEdgeInsetsMake(10, 10, 10, 10));
         expect(centerY.layoutConstant).to.equal(0);
 
-        MASViewConstraint *top = createConstraintWithLayoutAttribute(NSLayoutAttributeTop);
+        MASViewConstraint *top = [[MASViewConstraint alloc] initWithFirstViewAttribute:otherView.mas_top];
         top.insets(UIEdgeInsetsMake(15, 10, 10, 10));
         expect(top.layoutConstant).to.equal(15);
 
-        MASViewConstraint *left = createConstraintWithLayoutAttribute(NSLayoutAttributeLeft);
+        MASViewConstraint *left = [[MASViewConstraint alloc] initWithFirstViewAttribute:otherView.mas_left];
         left.insets(UIEdgeInsetsMake(10, 15, 10, 10));
         expect(left.layoutConstant).to.equal(15);
 
-        MASViewConstraint *bottom = createConstraintWithLayoutAttribute(NSLayoutAttributeBottom);
+        MASViewConstraint *bottom = [[MASViewConstraint alloc] initWithFirstViewAttribute:otherView.mas_bottom];
         bottom.insets(UIEdgeInsetsMake(10, 10, 15, 10));
         expect(bottom.layoutConstant).to.equal(-15);
 
-        MASViewConstraint *right = createConstraintWithLayoutAttribute(NSLayoutAttributeRight);
+        MASViewConstraint *right = [[MASViewConstraint alloc] initWithFirstViewAttribute:otherView.mas_right];
         right.insets(UIEdgeInsetsMake(10, 10, 10, 15));
         expect(right.layoutConstant).to.equal(-15);
     });
     
     it(@"should update center offset only", ^{
-        MASViewConstraint *width = createConstraintWithLayoutAttribute(NSLayoutAttributeWidth);
+        MASViewConstraint *width = [[MASViewConstraint alloc] initWithFirstViewAttribute:otherView.mas_width];
         width.centerOffset(CGPointMake(-20, -10));
         expect(width.layoutConstant).to.equal(0);
 
-        MASViewConstraint *centerX = createConstraintWithLayoutAttribute(NSLayoutAttributeCenterX);
+        MASViewConstraint *centerX = [[MASViewConstraint alloc] initWithFirstViewAttribute:otherView.mas_centerX];
         centerX.centerOffset(CGPointMake(-20, -10));
         expect(centerX.layoutConstant).to.equal(-20);
 
-        MASViewConstraint *centerY = createConstraintWithLayoutAttribute(NSLayoutAttributeCenterY);
+        MASViewConstraint *centerY = [[MASViewConstraint alloc] initWithFirstViewAttribute:otherView.mas_centerY];
         centerY.centerOffset(CGPointMake(-20, -10));
         expect(centerY.layoutConstant).to.equal(-10);
     });
     
     it(@"should update size offset only", ^{
-        MASViewConstraint *bottom = createConstraintWithLayoutAttribute(NSLayoutAttributeBottom);
+        MASViewConstraint *bottom = [[MASViewConstraint alloc] initWithFirstViewAttribute:otherView.mas_bottom];
         bottom.sizeOffset(CGSizeMake(-40, 55));
         expect(bottom.layoutConstant).to.equal(0);
 
-        MASViewConstraint *width = createConstraintWithLayoutAttribute(NSLayoutAttributeWidth);
+        MASViewConstraint *width = [[MASViewConstraint alloc] initWithFirstViewAttribute:otherView.mas_width];
         width.sizeOffset(CGSizeMake(-40, 55));
         expect(width.layoutConstant).to.equal(-40);
 
-        MASViewConstraint *height = createConstraintWithLayoutAttribute(NSLayoutAttributeHeight);
+        MASViewConstraint *height = [[MASViewConstraint alloc] initWithFirstViewAttribute:otherView.mas_height];
         height.sizeOffset(CGSizeMake(-40, 55));
         expect(height.layoutConstant).to.equal(55);
     });
 });
 
 describe(@"commit", ^{
-    
-    it(@"should create layout constraint", ^{
+
+    it(@"should create layout constraint on commit", ^{
+        MASViewAttribute *secondViewAttribute = otherView.mas_height;
         constraint.equalTo(secondViewAttribute);
         constraint.percent(0.5);
         constraint.offset(10);
         constraint.priority(345);
         [constraint commit];
-        
+
         expect(constraint.layoutConstraint.firstAttribute).to.equal(NSLayoutAttributeWidth);
         expect(constraint.layoutConstraint.secondAttribute).to.equal(NSLayoutAttributeHeight);
         expect(constraint.layoutConstraint.firstItem).to.beIdenticalTo(constraint.firstViewAttribute.view);
@@ -218,7 +235,7 @@ describe(@"commit", ^{
 
         expect(superview.constraints[0]).to.beIdenticalTo(constraint.layoutConstraint);
     });
-    
+
 });
 
 SpecEnd
\ No newline at end of file

-//
-//  SpecHelpers.h
-//  Masonry
-//
-//  Created by Jonas Budelmann on 23/07/13.
-//  Copyright (c) 2013 Jonas Budelmann. All rights reserved.
-//
-
-#import "MASCompositeConstraint.h"
-#import "MASViewAttribute.h"
-#import "MASViewConstraint.h"
-
-static id (^createViewAttribute)(NSLayoutAttribute layoutAttribute) = ^id(NSLayoutAttribute layoutAttribute) {
-    UIView *view = UIView.new;
-    MASViewAttribute *viewAttribute = [[MASViewAttribute alloc] initWithView:view layoutAttribute:layoutAttribute];
-    return viewAttribute;
-};
-
-static id (^createConstraintWithLayoutAttribute)(NSLayoutAttribute layoutAttribute) = ^id(NSLayoutAttribute layoutAttribute) {
-    id delegate = mockProtocol(@protocol(MASConstraintDelegate));
-    MASViewConstraint *constraint = [[MASViewConstraint alloc] initWithFirstViewAttribute:createViewAttribute(layoutAttribute)];
-    constraint.delegate = delegate;
-    return constraint;
-};
-
-static id(^createCompositeWithType)(MASCompositeViewConstraintType type) = ^id(MASCompositeViewConstraintType type){
-    id delegate = mockProtocol(@protocol(MASConstraintDelegate));
-    UIView *view = UIView.new;
-    MASCompositeConstraint *composite = [[MASCompositeConstraint alloc] initWithView:view type:type];
-    composite.delegate = delegate;
-    return composite;
-};
\ No newline at end of file