Address style feedback

1 files changed, 150 insertions, 143 deletions

diff --git a/app/assets/javascripts/copy_as_gfm.js.es6 b/app/assets/javascripts/copy_as_gfm.js.es6
index 4827f7b7420..f9098c7041c 100644
--- a/app/assets/javascripts/copy_as_gfm.js.es6
+++ b/app/assets/javascripts/copy_as_gfm.js.es6
@@ -1,192 +1,195 @@
 /* eslint-disable class-methods-use-this */
+/*jshint esversion: 6 */
 
 (() => {
   const gfmRules = {
     // Should have an entry for every filter in lib/banzai/pipeline/gfm_pipeline.rb,
     // in reverse order.
     // Should have test coverage in spec/features/copy_as_gfm_spec.rb.
-    "InlineDiffFilter": {
-      "span.idiff.addition": function(el, text) {
-        return "{+" + text + "+}";
+    InlineDiffFilter: {
+      'span.idiff.addition'(el, text) {
+        return `{+${text}+}`;
       },
-      "span.idiff.deletion": function(el, text) {
-        return "{-" + text + "-}";
+      'span.idiff.deletion'(el, text) {
+        return `{-${text}-}`;
       },
     },
-    "TaskListFilter": {
-      "input[type=checkbox].task-list-item-checkbox": function(el, text) {
-        return '[' + (el.checked ? 'x' : ' ') + ']';
+    TaskListFilter: {
+      'input[type=checkbox].task-list-item-checkbox'(el, text) {
+        return `[${el.checked ? 'x' : ' '}]`;
       }
     },
-    "ReferenceFilter": {
-      "a.gfm:not([data-link=true])": function(el, text) {
-        return el.getAttribute('data-original') || text;
+    ReferenceFilter: {
+      'a.gfm:not([data-link=true])'(el, text) {
+        return el.dataset.original || text;
       },
     },
-    "AutolinkFilter": {
-      "a": function(el, text) {
-        if (text != el.getAttribute("href")) {
-          // Fall back to handler for MarkdownFilter
-          return false;
-        }
+    AutolinkFilter: {
+      'a'(el, text) {
+        // Fallback on the regular MarkdownFilter's `a` handler.
+        if (text !== el.getAttribute('href')) return false;
 
         return text;
       },
     },
-    "TableOfContentsFilter": {
-      "ul.section-nav": function(el, text) {
-        return "[[_TOC_]]";
+    TableOfContentsFilter: {
+      'ul.section-nav'(el, text) {
+        return '[[_TOC_]]';
       },
     },
-    "EmojiFilter": {
-      "img.emoji": function(el, text) {
-        return el.getAttribute("alt");
+    EmojiFilter: {
+      'img.emoji'(el, text) {
+        return el.getAttribute('alt');
       },
     },
-    "ImageLinkFilter": {
-      "a.no-attachment-icon": function(el, text) {
+    ImageLinkFilter: {
+      'a.no-attachment-icon'(el, text) {
         return text;
       },
     },
-    "VideoLinkFilter": {
-      ".video-container": function(el, text) {
-        var videoEl = el.querySelector('video');
-        if (!videoEl) {
-          return false;
-        }
+    VideoLinkFilter: {
+      '.video-container'(el, text) {
+        let videoEl = el.querySelector('video');
+        if (!videoEl) return false;
 
         return CopyAsGFM.nodeToGFM(videoEl);
       },
-      "video": function(el, text) {
-        return "![" + el.getAttribute('data-title') + "](" + el.getAttribute("src") + ")";
+      'video'(el, text) {
+        return `![${el.dataset.title}](${el.getAttribute('src')})`;
       },
     },
-    "MathFilter": {
-      "pre.code.math[data-math-style='display']": function(el, text) {
-        return "```math\n" + text.trim() + "\n```";
+    MathFilter: {
+      'pre.code.math[data-math-style=display]'(el, text) {
+        return '```math\n' + text.trim() + '\n```';
       },
-      "code.code.math[data-math-style='inline']": function(el, text) {
-        return "$`" + text + "`$";
+      'code.code.math[data-math-style=inline]'(el, text) {
+        return '$`' + text + '`$';
       },
-      "span.katex-display span.katex-mathml": function(el, text) {
-        var mathAnnotation = el.querySelector('annotation[encoding="application/x-tex"]');
-        if (!mathAnnotation) {
-          return false;
-        }
+      'span.katex-display span.katex-mathml'(el, text) {
+        let mathAnnotation = el.querySelector('annotation[encoding="application/x-tex"]');
+        if (!mathAnnotation) return false;
 
-        return "```math\n" + CopyAsGFM.nodeToGFM(mathAnnotation)  + "\n```";
+        return '```math\n' + CopyAsGFM.nodeToGFM(mathAnnotation)  + '\n```';
       },
-      "span.katex-mathml": function(el, text) {
-        var mathAnnotation = el.querySelector('annotation[encoding="application/x-tex"]');
-        if (!mathAnnotation) {
-          return false;
-        }
+      'span.katex-mathml'(el, text) {
+        let mathAnnotation = el.querySelector('annotation[encoding="application/x-tex"]');
+        if (!mathAnnotation) return false;
 
-        return "$`" + CopyAsGFM.nodeToGFM(mathAnnotation) + "`$";
+        return '$`' + CopyAsGFM.nodeToGFM(mathAnnotation) + '`$';
       },
-      "span.katex-html": function(el, text) {
-        return "";
+      'span.katex-html'(el, text) {
+        // We don't want to include the content of this element in the copied text.
+        return '';
       },
-      'annotation[encoding="application/x-tex"]': function(el, text) {
+      'annotation[encoding="application/x-tex"]'(el, text) {
         return text.trim();
       }
     },
-    "SyntaxHighlightFilter": {
-      "pre.code.highlight": function(el, text) {
-        var lang = el.getAttribute("lang");
-        if (lang == "text") {
-          lang = "";
+    SyntaxHighlightFilter: {
+      'pre.code.highlight'(el, text) {
+        let lang = el.getAttribute('lang');
+        if (lang === 'text') {
+          lang = '';
         }
-        return "```" + lang + "\n" + text.trim() + "\n```";
+        return '```' + lang + '\n' + text.trim() + '\n```';
       },
-      "pre > code": function(el, text) {
+      'pre > code'(el, text) {
          // Don't wrap code blocks in ``
         return text;
       },
     },
-    "MarkdownFilter": {
-      "code": function(el, text) {
-        var backtickCount = 1;
-        var backtickMatch = text.match(/`+/);
+    MarkdownFilter: {
+      'code'(el, text) {
+        let backtickCount = 1;
+        let backtickMatch = text.match(/`+/);
         if (backtickMatch) {
           backtickCount = backtickMatch[0].length + 1;
         }
 
-        var backticks = new Array(backtickCount + 1).join('`');
-        var spaceOrNoSpace = backtickCount > 1 ? " " : "";
+        let backticks = new Array(backtickCount + 1).join('`');
+        let spaceOrNoSpace = backtickCount > 1 ? ' ' : '';
 
         return backticks + spaceOrNoSpace + text + spaceOrNoSpace + backticks;
       },
-      "blockquote": function(el, text) {
-        return text.trim().split('\n').map(function(s) { return ('> ' + s).trim(); }).join('\n');
+      'blockquote'(el, text) {
+        return text.trim().split('\n').map((s) => (`> ${s}`).trim()).join('\n');
       },
-      "img": function(el, text) {
-        return "![" + el.getAttribute("alt") + "](" + el.getAttribute("src") + ")";
+      'img'(el, text) {
+        return `![${el.getAttribute('alt')}](${el.getAttribute('src')})`;
       },
-      "a.anchor": function(el, text) {
+      'a.anchor'(el, text) {
+        // Don't render a Markdown link for the anchor link inside a heading
         return text;
       },
-      "a": function(el, text) {
-        return "[" + text + "](" + el.getAttribute("href") + ")";
-      },
-      "li": function(el, text) {
-        var lines = text.trim().split('\n');
-        var firstLine = '- ' + lines.shift();
-        var nextLines = lines.map(function(s) { return ('  ' + s).replace(/\s+$/, ''); });
+      'a'(el, text) {
+        return `[${text}](${el.getAttribute('href')})`;
+      },
+      'li'(el, text) {
+        let lines = text.trim().split('\n');
+        let firstLine = '- ' + lines.shift();
+        // Add two spaces to the front of subsequent list items lines, or leave the line entirely blank.
+        let nextLines = lines.map(function(s) {
+          if (s.trim().length === 0) {
+            return '';
+          } else {
+            return `  ${s}`;
+          }
+        });
 
-        return firstLine + '\n' + nextLines.join('\n');
+        return `${firstLine}\n${nextLines.join('\n')}`;
       },
-      "ul": function(el, text) {
+      'ul'(el, text) {
         return text;
       },
-      "ol": function(el, text) {
+      'ol'(el, text) {
+        // LIs get a `- ` prefix by default, which we replace by `1. ` for ordered lists.
         return text.replace(/^- /mg, '1. ');
       },
-      "h1": function(el, text) {
-        return '# ' + text.trim();
+      'h1'(el, text) {
+        return `# ${text.trim()}`;
       },
-      "h2": function(el, text) {
-        return '## ' + text.trim();
+      'h2'(el, text) {
+        return `## ${text.trim()}`;
       },
-      "h3": function(el, text) {
-        return '### ' + text.trim();
+      'h3'(el, text) {
+        return `### ${text.trim()}`;
       },
-      "h4": function(el, text) {
-        return '#### ' + text.trim();
+      'h4'(el, text) {
+        return `#### ${text.trim()}`;
       },
-      "h5": function(el, text) {
-        return '##### ' + text.trim();
+      'h5'(el, text) {
+        return `##### ${text.trim()}`;
       },
-      "h6": function(el, text) {
-        return '###### ' + text.trim();
+      'h6'(el, text) {
+        return `###### ${text.trim()}`;
       },
-      "strong": function(el, text) {
-        return '**' + text + '**';
+      'strong'(el, text) {
+        return `**${text}**`;
       },
-      "em": function(el, text) {
-        return '_' + text + '_';
+      'em'(el, text) {
+        return `_${text}_`;
       },
-      "del": function(el, text) {
-        return '~~' + text + '~~';
+      'del'(el, text) {
+        return `~~${text}~~`;
       },
-      "sup": function(el, text) {
-        return '^' + text;
+      'sup'(el, text) {
+        return `^${text}`;
       },
-      "hr": function(el, text) {
+      'hr'(el, text) {
         return '-----';
       },
-      "table": function(el, text) {
-        var theadText = CopyAsGFM.nodeToGFM(el.querySelector('thead'));
-        var tbodyText = CopyAsGFM.nodeToGFM(el.querySelector('tbody'));
+      'table'(el, text) {
+        let theadText = CopyAsGFM.nodeToGFM(el.querySelector('thead'));
+        let tbodyText = CopyAsGFM.nodeToGFM(el.querySelector('tbody'));
 
         return theadText + tbodyText;
       },
-      "thead": function(el, text) {
-        var cells = _.map(el.querySelectorAll('th'), function(cell) {
-          var chars = CopyAsGFM.nodeToGFM(cell).trim().length;
+      'thead'(el, text) {
+        let cells = _.map(el.querySelectorAll('th'), function(cell) {
+          let chars = CopyAsGFM.nodeToGFM(cell).trim().length;
 
-          var before = '';
-          var after = '';
+          let before = '';
+          let after = '';
           switch (cell.style.textAlign) {
             case 'center':
               before = ':';
@@ -201,17 +204,18 @@
 
           chars = Math.max(chars, 0);
 
-          var middle = new Array(chars + 1).join('-');
+          let middle = new Array(chars + 1).join('-');
 
           return before + middle + after;
         });
-        return text + '| ' + cells.join(' | ') + ' |';
+
+        return text + `| ${cells.join(' | ')} |`;
       },
-      "tr": function(el, text) {
-        var cells = _.map(el.querySelectorAll('td, th'), function(cell) {
+      'tr'(el, text) {
+        let cells = _.map(el.querySelectorAll('td, th'), function(cell) {
           return CopyAsGFM.nodeToGFM(cell).trim();
         });
-        return '| ' + cells.join(' | ') + ' |';
+        return `| ${cells.join(' | ')} |`;
       },
     }
   };
@@ -223,29 +227,29 @@
     }
 
     handleCopy(e) {
-      var clipboardData = e.originalEvent.clipboardData;
+      let clipboardData = e.originalEvent.clipboardData;
       if (!clipboardData) return;
 
       if (!window.getSelection) return;
 
-      var selection = window.getSelection();
+      let selection = window.getSelection();
       if (!selection.rangeCount || selection.rangeCount === 0) return;
 
-      var selectedDocument = selection.getRangeAt(0).cloneContents();
+      let selectedDocument = selection.getRangeAt(0).cloneContents();
       if (!selectedDocument) return;
 
       e.preventDefault();
       clipboardData.setData('text/plain', selectedDocument.textContent);
 
-      var gfm = CopyAsGFM.nodeToGFM(selectedDocument);
+      let gfm = CopyAsGFM.nodeToGFM(selectedDocument);
       clipboardData.setData('text/x-gfm', gfm);
     }
 
     handlePaste(e) {
-      var clipboardData = e.originalEvent.clipboardData;
+      let clipboardData = e.originalEvent.clipboardData;
       if (!clipboardData) return;
-      
-      var gfm = clipboardData.getData('text/x-gfm');
+
+      let gfm = clipboardData.getData('text/x-gfm');
       if (!gfm) return;
 
       e.preventDefault();
@@ -255,36 +259,39 @@
 
     insertText(target, text) {
       // Firefox doesn't support `document.execCommand('insertText', false, text);` on textareas
-      var selectionStart = target.selectionStart;
-      var selectionEnd = target.selectionEnd;
-      var value = target.value;
-      var textBefore = value.substring(0, selectionStart);
-      var textAfter  = value.substring(selectionEnd, value.length);
-      var newText = textBefore + text + textAfter;
+
+      let selectionStart = target.selectionStart;
+      let selectionEnd = target.selectionEnd;
+      let value = target.value;
+
+      let textBefore = value.substring(0, selectionStart);
+      let textAfter  = value.substring(selectionEnd, value.length);
+      let newText = textBefore + text + textAfter;
+
       target.value = newText;
       target.selectionStart = target.selectionEnd = selectionStart + text.length;
     }
 
     static nodeToGFM(node) {
-      if (node.nodeType == Node.TEXT_NODE) {
+      if (node.nodeType === Node.TEXT_NODE) {
         return node.textContent;
       }
 
-      var text = this.innerGFM(node);
+      let text = this.innerGFM(node);
 
-      if (node.nodeType == Node.DOCUMENT_FRAGMENT_NODE) {
+      if (node.nodeType === Node.DOCUMENT_FRAGMENT_NODE) {
         return text;
       }
 
-      for (var filter in gfmRules) {
-        var rules = gfmRules[filter];
+      for (let filter in gfmRules) {
+        let rules = gfmRules[filter];
 
-        for (var selector in rules) {
-          var func = rules[selector];
+        for (let selector in rules) {
+          let func = rules[selector];
 
           if (!node.matches(selector)) continue;
 
-          var result = func(node, text);
+          let result = func(node, text);
           if (result === false) continue;
 
           return result;
@@ -295,16 +302,16 @@
     }
 
     static innerGFM(parentNode) {
-      var nodes = parentNode.childNodes;
+      let nodes = parentNode.childNodes;
 
-      var clonedParentNode = parentNode.cloneNode(true);
-      var clonedNodes = Array.prototype.slice.call(clonedParentNode.childNodes, 0);
+      let clonedParentNode = parentNode.cloneNode(true);
+      let clonedNodes = Array.prototype.slice.call(clonedParentNode.childNodes, 0);
 
-      for (var i = 0; i < nodes.length; i++) {
-        var node = nodes[i];
-        var clonedNode = clonedNodes[i];
+      for (let i = 0; i < nodes.length; i++) {
+        let node = nodes[i];
+        let clonedNode = clonedNodes[i];
 
-        var text = this.nodeToGFM(node);
+        let text = this.nodeToGFM(node);
         clonedNode.parentNode.replaceChild(document.createTextNode(text), clonedNode);
       }