1 files changed, 57 insertions, 0 deletions
diff --git a/devtools/client/webconsole/utils/clipboard.js b/devtools/client/webconsole/utils/clipboard.js
new file mode 100644
index 0000000000..72b064f323
--- /dev/null
+++ b/devtools/client/webconsole/utils/clipboard.js
@@ -0,0 +1,57 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Get the text of the element parameter, as provided by the Selection API. We need to
+ * rely on the Selection API as it mimics exactly what the user would have if they do a
+ * selection using the mouse and copy it. `HTMLElement.textContent` and
+ * `HTMLElement.innerText` follow a different codepath than user selection + copy.
+ * They both have issues when dealing with whitespaces, and therefore can't be used to
+ * have a reliable result.
+ *
+ * As the Selection API is exposed through the Window object, if we don't have a window
+ * we fallback to `HTMLElement.textContent`.
+ *
+ * @param {HTMLElement} el: The element we want the text of.
+ * @returns {String|null} The text of the element, or null if el is falsy.
+ */
+function getElementText(el) {
+  if (!el) {
+    return null;
+  }
+  // If we can, we use the Selection API to match what the user would get if they
+  // manually select and copy the message.
+  const doc = el.ownerDocument;
+  const win = doc && doc.defaultView;
+
+  if (!win) {
+    return el.textContent;
+  }
+
+  // We store the current selected range and unselect everything.
+  const selection = win.getSelection();
+  const currentSelectedRange =
+    !selection.isCollapsed && selection.getRangeAt(0);
+  selection.removeAllRanges();
+
+  // Then creates a range from `el`, and get the text content.
+  const range = doc.createRange();
+  range.selectNode(el);
+  selection.addRange(range);
+  const text = selection.toString();
+
+  // Finally we revert the selection to what it was.
+  selection.removeRange(range);
+  if (currentSelectedRange) {
+    selection.addRange(currentSelectedRange);
+  }
+
+  return text;
+}
+
+module.exports = {
+  getElementText,
+};