Respond to code review feedback

 - {show, hide} => {renders, doesn't render} to clarify that we're
   checking whether an element is rendered at all, as opposed to merely
   visually hidden
 - Replace ambiguous GitHub issue reference with URL

src/sidebar/components/test/search-input-test.js

@@ -62,25 +62,25 @@ describe('SearchInput', () => {
     assert.calledWith(onSearch, { $query: 'new-query' });
   });
 
-  it('shows loading indicator when app is in a "loading" state', () => {
+  it('renders loading indicator when app is in a "loading" state', () => {
     fakeStore.isLoading.returns(true);
     const wrapper = createSearchInput();
     assert.isTrue(wrapper.exists('Spinner'));
   });
 
-  it('hides search button when app is in "loading" state', () => {
+  it('doesn\'t render search button when app is in "loading" state', () => {
     fakeStore.isLoading.returns(true);
     const wrapper = createSearchInput();
     assert.isFalse(wrapper.exists('button'));
   });
 
-  it('hides loading indicator when app is not in "loading" state', () => {
+  it('renders loading indicator when app is not in "loading" state', () => {
     fakeStore.isLoading.returns(false);
     const wrapper = createSearchInput();
     assert.isFalse(wrapper.exists('Spinner'));
   });
 
-  it('shows search button when app is not in "loading" state', () => {
+  it('doesn\'t render search button when app is not in "loading" state', () => {
     fakeStore.isLoading.returns(false);
     const wrapper = createSearchInput();
     assert.isTrue(wrapper.exists('button'));

src/styles/sidebar/components/search-input.scss

@@ -27,7 +27,7 @@
   // `max-width` property. In Safari, the <input> will not accept
   // focus if `max-width` is set to 0px so we set it to
   // a near-zero positive value instead.
-  // See GH #2654
+  // See https://github.com/hypothesis/h/issues/2654
   max-width: 0.1px;
 
   transition: max-width .3s ease-out, padding-left .3s ease-out;