1 files changed, 44 insertions, 0 deletions
diff --git a/app/assets/javascripts/lib/utils/highlight.js b/app/assets/javascripts/lib/utils/highlight.js
new file mode 100644
index 00000000000..4f7eff2cca1
--- /dev/null
+++ b/app/assets/javascripts/lib/utils/highlight.js
@@ -0,0 +1,44 @@
+import fuzzaldrinPlus from 'fuzzaldrin-plus';
+import _ from 'underscore';
+import sanitize from 'sanitize-html';
+
+/**
+ * Wraps substring matches with HTML `<span>` elements.
+ * Inputs are sanitized before highlighting, so this
+ * filter is safe to use with `v-html` (as long as `matchPrefix`
+ * and `matchSuffix` are not being dynamically generated).
+ *
+ * Note that this function can't be used inside `v-html` as a filter
+ * (Vue filters cannot be used inside `v-html`).
+ *
+ * @param {String} string The string to highlight
+ * @param {String} match The substring match to highlight in the string
+ * @param {String} matchPrefix The string to insert at the beginning of a match
+ * @param {String} matchSuffix The string to insert at the end of a match
+ */
+export default function highlight(string, match = '', matchPrefix = '<b>', matchSuffix = '</b>') {
+  if (_.isUndefined(string) || _.isNull(string)) {
+    return '';
+  }
+
+  if (_.isUndefined(match) || _.isNull(match) || match === '') {
+    return string;
+  }
+
+  const sanitizedValue = sanitize(string.toString(), { allowedTags: [] });
+
+  // occurences is an array of character indices that should be
+  // highlighted in the original string, i.e. [3, 4, 5, 7]
+  const occurences = fuzzaldrinPlus.match(sanitizedValue, match.toString());
+
+  return sanitizedValue
+    .split('')
+    .map((character, i) => {
+      if (_.contains(occurences, i)) {
+        return `${matchPrefix}${character}${matchSuffix}`;
+      }
+
+      return character;
+    })
+    .join('');
+}