fixed commit diff linking and added specs

app/assets/javascripts/diff.js.es6

@@ -20,7 +20,7 @@
         .on('click', '.js-unfold', this.handleClickUnfold.bind(this))
         .on('click', '.diff-line-num a', this.handleClickLineNum.bind(this));
 
-      this.highlighSelectedLine();
+      this.openAnchoredDiff();
     }
 
     handleClickUnfold(e) {
@@ -61,13 +61,22 @@
       $.get(link, params, response => $target.parent().replaceWith(response));
     }
 
-    openAnchoredDiff(anchoredDiff, cb) {
-      const diffTitle = $(`#file-path-${anchoredDiff}`);
+    openAnchoredDiff(cb) {
+      const locationHash = gl.utils.getLocationHash();
+      const anchoredDiff = locationHash && locationHash.split('_')[0];
+
+      if (!anchoredDiff) return;
+
+      const diffTitle = $(`#${anchoredDiff}`);
       const diffFile = diffTitle.closest('.diff-file');
       const nothingHereBlock = $('.nothing-here-block:visible', diffFile);
       if (nothingHereBlock.length) {
-        diffFile.singleFileDiff(true, cb);
-      } else {
+        const clickTarget = $('.file-title, .click-to-expand', diffFile);
+        diffFile.data('singleFileDiff').toggleDiff(clickTarget, () => {
+          this.highlighSelectedLine();
+          if (cb) cb();
+        });
+      } else if (cb) {
         cb();
       }
     }

app/assets/javascripts/merge_request_tabs.js.es6

@@ -237,13 +237,8 @@
           }
           this.diffsLoaded = true;
 
-          const diffPage = new gl.Diff();
-
-          const locationHash = gl.utils.getLocationHash();
-          const anchoredDiff = locationHash && locationHash.split('_')[0];
-          if (anchoredDiff) {
-            diffPage.openAnchoredDiff(anchoredDiff, () => this.scrollToElement('#diffs'));
-          }
+          new gl.Diff();
+          this.scrollToElement('#diffs');
         },
       });
     }

app/assets/javascripts/single_file_diff.js

-/* eslint-disable func-names, space-before-function-paren, no-var, space-before-blocks, prefer-rest-params, wrap-iife, one-var, one-var-declaration-per-line, consistent-return, no-param-reassign, padded-blocks, max-len */
+/* eslint-disable func-names, prefer-arrow-callback, space-before-function-paren, no-var, space-before-blocks, prefer-rest-params, wrap-iife, one-var, one-var-declaration-per-line, consistent-return, no-param-reassign, padded-blocks, max-len */
 
 (function() {
   var bind = function(fn, me){ return function(){ return fn.apply(me, arguments); }; };
@@ -14,8 +14,7 @@
 
     COLLAPSED_HTML = '<div class="nothing-here-block diff-collapsed">This diff is collapsed. <a class="click-to-expand">Click to expand it.</a></div>';
 
-    function SingleFileDiff(file, forceLoad, cb) {
-      var clickTarget;
+    function SingleFileDiff(file) {
       this.file = file;
       this.toggleDiff = bind(this.toggleDiff, this);
       this.content = $('.diff-content', this.file);
@@ -33,14 +32,13 @@
         this.content.after(this.collapsedContent);
         this.$toggleIcon.addClass('fa-caret-down');
       }
-      clickTarget = $('.file-title, .click-to-expand', this.file).on('click', this.toggleDiff);
-      if (forceLoad) {
-        this.toggleDiff({ target: clickTarget }, cb);
-      }
+
+      $('.file-title, .click-to-expand', this.file).on('click', (function (e) {
+        this.toggleDiff($(e.target));
+      }).bind(this));
     }
 
-    SingleFileDiff.prototype.toggleDiff = function(e, cb) {
-      var $target = $(e.target);
+    SingleFileDiff.prototype.toggleDiff = function($target, cb) {
       if (!$target.hasClass('file-title') && !$target.hasClass('click-to-expand') && !$target.hasClass('diff-toggle-caret')) return;
       this.isOpen = !this.isOpen;
       if (!this.isOpen && !this.hasError) {
@@ -91,10 +89,10 @@
 
   })();
 
-  $.fn.singleFileDiff = function(forceLoad, cb) {
+  $.fn.singleFileDiff = function() {
     return this.each(function() {
-      if (!$.data(this, 'singleFileDiff') || forceLoad) {
-        return $.data(this, 'singleFileDiff', new window.SingleFileDiff(this, forceLoad, cb));
+      if (!$.data(this, 'singleFileDiff')) {
+        return $.data(this, 'singleFileDiff', new window.SingleFileDiff(this));
       }
     });
   };

app/views/projects/diffs/_file.html.haml

 .diff-file.file-holder{ id: file_hash, data: diff_file_html_data(project, diff_file.file_path, diff_commit.id) }
-  .file-title{ id: "file-path-#{hexdigest(diff_file.file_path)}" }
+  .file-title
     = render "projects/diffs/file_header", diff_file: diff_file, blob: blob, diff_commit: diff_commit, project: project, url: "##{file_hash}"
 
     - unless diff_file.submodule?

spec/features/expand_collapse_diffs_spec.rb

@@ -4,10 +4,10 @@ feature 'Expand and collapse diffs', js: true, feature: true do
   include WaitForAjax
 
   let(:branch) { 'expand-collapse-diffs' }
+  let(:project) { create(:project) }
 
   before do
     login_as :admin
-    project = create(:project)
 
     # Ensure that undiffable.md is in .gitattributes
     project.repository.copy_gitattributes(branch)
@@ -31,6 +31,33 @@ feature 'Expand and collapse diffs', js: true, feature: true do
     define_method(file.split('.').first) { file_container(file) }
   end
 
+  it 'should show the diff content with a highlighted line when linking to line' do
+    expect(large_diff).not_to have_selector('.code')
+    expect(large_diff).to have_selector('.nothing-here-block')
+
+    visit namespace_project_commit_path(project.namespace, project, project.commit(branch), anchor: "#{large_diff[:id]}_0_1")
+    execute_script('window.location.reload()')
+
+    wait_for_ajax
+
+    expect(large_diff).to have_selector('.code')
+    expect(large_diff).not_to have_selector('.nothing-here-block')
+    expect(large_diff).to have_selector('.hll')
+  end
+
+  it 'should show the diff content when linking to file' do
+    expect(large_diff).not_to have_selector('.code')
+    expect(large_diff).to have_selector('.nothing-here-block')
+
+    visit namespace_project_commit_path(project.namespace, project, project.commit(branch), anchor: large_diff[:id])
+    execute_script('window.location.reload()')
+
+    wait_for_ajax
+
+    expect(large_diff).to have_selector('.code')
+    expect(large_diff).not_to have_selector('.nothing-here-block')
+  end
+
   context 'visiting a commit with collapsed diffs' do
     it 'shows small diffs immediately' do
       expect(small_diff).to have_selector('.code')