feat: Cmd-A inside code block should select block contents, closes #6498

shared/editor/commands/selectAll.ts

@@ -0,0 +1,39 @@
+import { NodeType } from "prosemirror-model";
+import { Command, TextSelection } from "prosemirror-state";
+import { findParentNode } from "../queries/findParentNode";
+
+/**
+ * Selects all the content of the given node type.
+ *
+ * @param type The node type
+ * @returns A prosemirror command.
+ */
+export function selectAll(type: NodeType): Command {
+  return (state, dispatch) => {
+    const code = findParentNode((node) => node.type === type)(state.selection);
+
+    if (code) {
+      const start = code.pos;
+      const end = code.pos + code.node.nodeSize;
+
+      if (
+        start === state.selection.from - 1 &&
+        end === state.selection.to + 1
+      ) {
+        return false;
+      }
+
+      dispatch?.(
+        state.tr.setSelection(
+          TextSelection.between(
+            state.doc.resolve(start),
+            state.doc.resolve(end)
+          )
+        )
+      );
+      return true;
+    }
+
+    return false;
+  };
+}