1 files changed, 32 insertions, 0 deletions
diff --git a/app/assets/javascripts/content_editor/services/code_suggestion_utils.js b/app/assets/javascripts/content_editor/services/code_suggestion_utils.js
new file mode 100644
index 00000000000..836729790ae
--- /dev/null
+++ b/app/assets/javascripts/content_editor/services/code_suggestion_utils.js
@@ -0,0 +1,32 @@
+export function langParamsToLineOffset(langParams) {
+  if (!langParams) return [0, 0];
+  const match = langParams.match(/([-+]\d+)([-+]\d+)/);
+  return match ? [parseInt(match[1], 10), parseInt(match[2], 10)] : [0, 0];
+}
+
+export function lineOffsetToLangParams(lineOffset) {
+  let langParams = '';
+  langParams += lineOffset[0] <= 0 ? `-${-lineOffset[0]}` : `+${lineOffset[0]}`;
+  langParams += lineOffset[1] < 0 ? lineOffset[1] : `+${lineOffset[1]}`;
+  return langParams;
+}
+
+export function toAbsoluteLineOffset(lineOffset, lineNumber) {
+  return [lineOffset[0] + lineNumber, lineOffset[1] + lineNumber];
+}
+
+export function getLines(absoluteLineOffset, allLines) {
+  return allLines.slice(absoluteLineOffset[0] - 1, absoluteLineOffset[1]);
+}
+
+// \u200b is a zero width space character (Alternatively &ZeroWidthSpace;, &#8203; or &#x200B;).
+// Due to the nature of HTML, if you have a blank line in the deleted/inserted code, it would
+// render with 0 height. (Each line is in its <code> element.) This means that blank lines
+// would be skipped when rendering the diff.
+// We append this character to the end of each line to make sure that the line is not empty
+// and the line numbers are rendered correctly.
+const ZERO_WIDTH_SPACE = '\u200b';
+
+export function appendNewlines(lines) {
+  return lines.map((l, i, arr) => `${l}${ZERO_WIDTH_SPACE}${i === arr.length - 1 ? '' : '\n'}`);
+}