fix(checkbox): no side margin if label has no content

* Remove side margin in checkbox if label has no content.
* Use `checkboxNativeElement` instead of `checkboxDebugElement.nativeElement` in expect statements.
* Fix typo.

Closes #2011

Author: belev

src/lib/checkbox/checkbox.html

@@ -1,5 +1,6 @@
 <label class="md-checkbox-layout">
-  <div class="md-checkbox-inner-container">
+  <div class="md-checkbox-inner-container"
+       [class.md-checkbox-inner-container-no-side-margin]="!hasLabel">
     <input #input
            class="md-checkbox-input md-visually-hidden" type="checkbox"
            [id]="inputId"
@@ -36,7 +37,7 @@
       <div class="md-checkbox-mixedmark"></div>
     </div>
   </div>
-  <span class="md-checkbox-label">
+  <span class="md-checkbox-label" #labelWrapper>
     <ng-content></ng-content>
   </span>
 </label>

src/lib/checkbox/checkbox.scss

@@ -227,6 +227,13 @@ md-checkbox {
       right: auto;
     }
   }
+
+  &.md-checkbox-inner-container-no-side-margin {
+    margin: {
+      left: 0;
+      right: 0;
+    }
+  }
 }
 
 // TODO(kara): Remove this style when fixing vertical baseline
@@ -292,6 +299,13 @@ md-checkbox {
         right: $md-checkbox-item-spacing;
       }
     }
+
+    &.md-checkbox-inner-container-no-side-margin {
+      margin: {
+        left: 0;
+        right: 0;
+      }
+    }
   }
 }
 

src/lib/checkbox/checkbox.spec.ts

@@ -36,6 +36,7 @@ describe('MdCheckbox', () => {
         CheckboxWithNameAttribute,
         CheckboxWithChangeEvent,
         CheckboxWithFormControl,
+        CheckboxWithoutLabel,
       ],
       providers: [
         {provide: ViewportRuler, useClass: FakeViewportRuler},
@@ -181,7 +182,7 @@ describe('MdCheckbox', () => {
       expect(rippleElement).toBeFalsy('Expected a disabled checkbox not to have a ripple');
     });
 
-    it('should not toggle `checked` state upon interation while disabled', () => {
+    it('should not toggle `checked` state upon interaction while disabled', () => {
       testComponent.isDisabled = true;
       fixture.detectChanges();
 
@@ -308,28 +309,28 @@ describe('MdCheckbox', () => {
       it('should apply class based on color attribute', () => {
         testComponent.checkboxColor = 'primary';
         fixture.detectChanges();
-        expect(checkboxDebugElement.nativeElement.classList.contains('md-primary')).toBe(true);
+        expect(checkboxNativeElement.classList.contains('md-primary')).toBe(true);
 
         testComponent.checkboxColor = 'accent';
         fixture.detectChanges();
-        expect(checkboxDebugElement.nativeElement.classList.contains('md-accent')).toBe(true);
+        expect(checkboxNativeElement.classList.contains('md-accent')).toBe(true);
       });
 
       it('should should not clear previous defined classes', () => {
-        checkboxDebugElement.nativeElement.classList.add('custom-class');
+        checkboxNativeElement.classList.add('custom-class');
 
         testComponent.checkboxColor = 'primary';
         fixture.detectChanges();
 
-        expect(checkboxDebugElement.nativeElement.classList.contains('md-primary')).toBe(true);
-        expect(checkboxDebugElement.nativeElement.classList.contains('custom-class')).toBe(true);
+        expect(checkboxNativeElement.classList.contains('md-primary')).toBe(true);
+        expect(checkboxNativeElement.classList.contains('custom-class')).toBe(true);
 
         testComponent.checkboxColor = 'accent';
         fixture.detectChanges();
 
-        expect(checkboxDebugElement.nativeElement.classList.contains('md-primary')).toBe(false);
-        expect(checkboxDebugElement.nativeElement.classList.contains('md-accent')).toBe(true);
-        expect(checkboxDebugElement.nativeElement.classList.contains('custom-class')).toBe(true);
+        expect(checkboxNativeElement.classList.contains('md-primary')).toBe(false);
+        expect(checkboxNativeElement.classList.contains('md-accent')).toBe(true);
+        expect(checkboxNativeElement.classList.contains('custom-class')).toBe(true);
 
       });
     });
@@ -588,7 +589,6 @@ describe('MdCheckbox', () => {
     });
   });
 
-
   describe('with form control', () => {
     let checkboxDebugElement: DebugElement;
     let checkboxInstance: MdCheckbox;
@@ -617,6 +617,20 @@ describe('MdCheckbox', () => {
       expect(checkboxInstance.disabled).toBe(false);
     });
   });
+
+  describe('without label', () => {
+    let checkboxDebugElement: DebugElement;
+    let checkboxNativeElement: HTMLElement;
+
+    it('should add a css class to inner-container to remove side margin', () => {
+      fixture = TestBed.createComponent(CheckboxWithoutLabel);
+      fixture.detectChanges();
+      checkboxDebugElement = fixture.debugElement.query(By.directive(MdCheckbox));
+      checkboxNativeElement = checkboxDebugElement.nativeElement;
+
+      expect(checkboxNativeElement.querySelectorAll('.md-checkbox-inner-container-no-side-margin').length).toBe(1);
+    });
+  });
 });
 
 /** Simple component for testing a single checkbox. */
@@ -724,3 +738,9 @@ class CheckboxWithChangeEvent {
 class CheckboxWithFormControl {
   formControl = new FormControl();
 }
+
+/** Test component without label */
+@Component({
+  template: `<md-checkbox></md-checkbox>`
+})
+class CheckboxWithoutLabel {}

src/lib/checkbox/checkbox.ts

@@ -141,6 +141,13 @@ export class MdCheckbox implements ControlValueAccessor {
   /** The native `<input type=checkbox> element */
   @ViewChild('input') _inputElement: ElementRef;
 
+  @ViewChild('labelWrapper') _labelWrapper: ElementRef;
+
+  get hasLabel(): boolean {
+    const labelWrapperTextContent = this._labelWrapper.nativeElement.textContent;
+    return labelWrapperTextContent && labelWrapperTextContent.trim().length > 0;
+  }
+
   /** Called when the checkbox is blurred. Needed to properly implement ControlValueAccessor. */
   onTouched: () => any = () => {};