Fix copying task logs dropping rows that scrolled out of view

airflow-core/src/airflow/ui/src/components/renderStructuredLog.tsx

@@ -352,6 +352,7 @@ const renderStructuredLogImpl = ({
   return (
     <chakra.div alignItems="flex-start" display="flex" key={index} lineHeight={1.5}>
       <RouterLink
+        data-copy-exclude
         id={index.toString()}
         key={`line_${index}`}
         style={{

airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/Logs.test.tsx

@@ -439,6 +439,24 @@ describe("Task log search", () => {
   }, 10_000);
 });
 
+const makeClipboardData = () => {
+  const store = new Map<string, string>();
+
+  return {
+    getData: (type: string) => store.get(type) ?? "",
+    setData: (type: string, value: string) => store.set(type, value),
+  };
+};
+
+const dispatchCopy = (clipboardData: ReturnType<typeof makeClipboardData>) => {
+  const copyEvent = new Event("copy", { bubbles: true, cancelable: true });
+
+  Object.defineProperty(copyEvent, "clipboardData", { value: clipboardData });
+  document.dispatchEvent(copyEvent);
+
+  return copyEvent;
+};
+
 const findRow = (text: string) => {
   const container = screen.getByTestId("virtual-scroll-container");
 
@@ -456,6 +474,101 @@ const withFakeSelection = <T,>(selection: Selection, callback: () => T): T => {
   return result;
 };
 
+describe("Copy across virtualized rows", () => {
+  it("rebuilds a removed grouped row from log data and strips line numbers", async () => {
+    render(
+      <AppWrapper initialEntries={["/dags/log_grouping/runs/manual__2025-02-18T12:19/tasks/ti_context"]} />,
+    );
+    await waitForLogs();
+
+    fireEvent.click(screen.getByTestId("summary-Pre Execute"));
+    await waitFor(() => expect(screen.getByText(/DAG bundles loaded/iu)).toBeInTheDocument());
+
+    const firstRow = findRow("Task started");
+    const middleRow = findRow("DAG bundles loaded");
+    const lastRow = findRow("Done. Returned value was: None");
+
+    expect(firstRow).toBeDefined();
+    expect(middleRow).toBeDefined();
+    expect(lastRow).toBeDefined();
+
+    middleRow.remove();
+
+    const range = document.createRange();
+
+    range.setStart(firstRow, 0);
+    range.setEnd(lastRow, lastRow.childNodes.length);
+
+    const selection = { getRangeAt: () => range, isCollapsed: false, rangeCount: 1 } as unknown as Selection;
+    const clipboardData = makeClipboardData();
+    const copyEvent = withFakeSelection(selection, () => dispatchCopy(clipboardData));
+
+    expect(copyEvent.defaultPrevented).toBe(true);
+
+    const lines = clipboardData.getData("text/plain").split("\n");
+
+    expect(lines[0]).not.toMatch(/^\d/u);
+    expect(lines[0]).toContain("Task started");
+    expect(lines).toContainEqual(
+      expect.stringMatching(/^\[.+\] INFO - DAG bundles loaded: dags-folder, example_dags$/u),
+    );
+  });
+
+  it("rebuilds a removed ungrouped row from log data", async () => {
+    render(
+      <AppWrapper initialEntries={["/dags/log_grouping/runs/manual__2025-02-18T12:19/tasks/ti_context"]} />,
+    );
+    await waitForLogs();
+
+    const firstRow = findRow("Log message source details");
+    const middleRow = findRow("Task started");
+    const lastRow = findRow("Done. Returned value was: None");
+
+    expect(firstRow).toBeDefined();
+    expect(middleRow).toBeDefined();
+    expect(lastRow).toBeDefined();
+
+    middleRow.remove();
+
+    const range = document.createRange();
+
+    range.setStart(firstRow, 0);
+    range.setEnd(lastRow, lastRow.childNodes.length);
+
+    const selection = { getRangeAt: () => range, isCollapsed: false, rangeCount: 1 } as unknown as Selection;
+    const clipboardData = makeClipboardData();
+    const copyEvent = withFakeSelection(selection, () => dispatchCopy(clipboardData));
+
+    expect(copyEvent.defaultPrevented).toBe(true);
+    expect(clipboardData.getData("text/plain").split("\n")).toContainEqual(
+      expect.stringMatching(/^\[.+\] INFO - Task started$/u),
+    );
+  });
+
+  it("leaves single-row selections to native copy", async () => {
+    render(
+      <AppWrapper initialEntries={["/dags/log_grouping/runs/manual__2025-02-18T12:19/tasks/ti_context"]} />,
+    );
+    await waitForLogs();
+
+    const row = findRow("Task started");
+
+    expect(row).toBeDefined();
+
+    const range = document.createRange();
+
+    range.setStart(row, 0);
+    range.setEnd(row, row.childNodes.length);
+
+    const selection = { getRangeAt: () => range, isCollapsed: false, rangeCount: 1 } as unknown as Selection;
+    const clipboardData = makeClipboardData();
+    const copyEvent = withFakeSelection(selection, () => dispatchCopy(clipboardData));
+
+    expect(copyEvent.defaultPrevented).toBe(false);
+    expect(clipboardData.getData("text/plain")).toBe("");
+  });
+});
+
 describe("Selection pinning across scrolling", () => {
   it("keeps the selection-anchor row mounted after scrolling it out of the render window", async () => {
     render(

airflow-core/src/airflow/ui/src/pages/TaskInstance/Logs/TaskLogContent.tsx

@@ -29,7 +29,12 @@ import type { ParsedLogEntry } from "src/queries/useLogs";
 
 import { HighlightedText } from "./HighlightedText";
 import { ScrollToButton } from "./ScrollToButton";
-import { getSelectionPinnedRows, mergePinnedIndexes } from "./logSelection";
+import {
+  extractSelectedLogText,
+  getEntryText,
+  getSelectionPinnedRows,
+  mergePinnedIndexes,
+} from "./logSelection";
 import { useLogGroups } from "./useLogGroups";
 import { getHighlightColor, isSelectionWithin, scrollToBottom, scrollToTop } from "./utils";
 
@@ -125,6 +130,36 @@ export const TaskLogContent = ({
     return () => document.removeEventListener("selectionchange", handleSelectionChange);
   }, []);
 
+  useEffect(() => {
+    const handleCopy = (event: ClipboardEvent) => {
+      const container = parentRef.current;
+      const selection = document.getSelection();
+
+      if (!container || !selection || !event.clipboardData) {
+        return;
+      }
+      const text = extractSelectedLogText({
+        container,
+        getRowText: (index) => {
+          const entry = visibleItems[index]?.entry;
+
+          return entry ? getEntryText(entry) : "";
+        },
+        selection,
+      });
+
+      if (text === undefined) {
+        return;
+      }
+      event.preventDefault();
+      event.clipboardData.setData("text/plain", text);
+    };
+
+    document.addEventListener("copy", handleCopy);
+
+    return () => document.removeEventListener("copy", handleCopy);
+  }, [visibleItems]);
+
   useLayoutEffect(() => {
     if (visibleItems.length === 0) {
       return;