Maintainer feedback changes

* Tweak styles
* Refactor diff_utils

ee/app/assets/javascripts/vulnerabilities/components/generic_report/types/diff.vue

@@ -36,13 +36,13 @@ export default {
       return this.diffData.filter(this.shouldShowLine);
     },
     isDiffView() {
-      return this.view === VIEW_TYPES.DIFF;
+      return this.view === this.$options.viewTypes.DIFF;
     },
     isBeforeView() {
-      return this.view === VIEW_TYPES.BEFORE;
+      return this.view === this.$options.viewTypes.BEFORE;
     },
     isAfterView() {
-      return this.view === VIEW_TYPES.AFTER;
+      return this.view === this.$options.viewTypes.AFTER;
     },
   },
   methods: {
@@ -110,10 +110,10 @@ export default {
         class="line_holder"
         data-testid="diffLine"
       >
-        <td class="diff-line-num old_line gl-border-t-0 gl-border-b-0" :class="changeClass(line)">
+        <td class="diff-line-num gl-border-t-0 gl-border-b-0" :class="changeClass(line)">
           {{ line.oldLine }}
         </td>
-        <td class="diff-line-num new_line gl-border-t-0 gl-border-b-0" :class="changeClass(line)">
+        <td class="diff-line-num gl-border-t-0 gl-border-b-0" :class="changeClass(line)">
           {{ line.newLine }}
         </td>
         <td data-testid="diffContent" class="line_content" :class="changeClass(line)">

ee/app/assets/javascripts/vulnerabilities/components/generic_report/types/diff_utils.js

@@ -8,11 +8,11 @@ import { LINE_TYPES } from './constants';
 
 export function splitAction(action) {
   const splitValues = action.value.split(/(\n)/);
-  if (
-    splitValues.length >= 2 &&
-    splitValues[splitValues.length - 1] === '' &&
-    splitValues[splitValues.length - 2] === '\n'
-  ) {
+
+  const isEmptyCharacter = splitValues[splitValues.length - 1] === '';
+  const isNewLine = splitValues[splitValues.length - 2] === '\n';
+
+  if (splitValues.length >= 2 && isEmptyCharacter && isNewLine) {
     splitValues.pop();
   }
   return splitValues.map((splitValue) => ({
@@ -110,14 +110,12 @@ function splitLinesInline(lines) {
 
 export function groupActionsByLines(actions) {
   const res = [];
-  let currLine = null;
+  let currLine = { actions: [] };
+
   const newLine = () => {
-    if (currLine !== null) {
     res.push(currLine);
-    }
     currLine = { actions: [] };
   };
-  newLine();
 
   actions.forEach((action) => {
     if (action.added) {