1 files changed, 35 insertions, 0 deletions
diff --git a/app/assets/javascripts/blob/blob_line_permalink_updater.js b/app/assets/javascripts/blob/blob_line_permalink_updater.js
new file mode 100644
index 00000000000..c8f68860fbd
--- /dev/null
+++ b/app/assets/javascripts/blob/blob_line_permalink_updater.js
@@ -0,0 +1,35 @@
+const lineNumberRe = /^L[0-9]+/;
+
+const updateLineNumbersOnBlobPermalinks = (linksToUpdate) => {
+  const hash = gl.utils.getLocationHash();
+  if (hash && lineNumberRe.test(hash)) {
+    const hashUrlString = `#${hash}`;
+
+    [].concat(Array.prototype.slice.call(linksToUpdate)).forEach((permalinkButton) => {
+      const baseHref = permalinkButton.getAttribute('data-original-href') || (() => {
+        const href = permalinkButton.getAttribute('href');
+        permalinkButton.setAttribute('data-original-href', href);
+        return href;
+      })();
+      permalinkButton.setAttribute('href', `${baseHref}${hashUrlString}`);
+    });
+  }
+};
+
+function BlobLinePermalinkUpdater(blobContentHolder, lineNumberSelector, elementsToUpdate) {
+  const updateBlameAndBlobPermalinkCb = () => {
+    // Wait for the hash to update from the LineHighlighter callback
+    setTimeout(() => {
+      updateLineNumbersOnBlobPermalinks(elementsToUpdate);
+    }, 0);
+  };
+
+  blobContentHolder.addEventListener('click', (e) => {
+    if (e.target.matches(lineNumberSelector)) {
+      updateBlameAndBlobPermalinkCb();
+    }
+  });
+  updateBlameAndBlobPermalinkCb();
+}
+
+export default BlobLinePermalinkUpdater;