test(web): cover mobile line-copy null cases

Author: pallyoung

packages/web/src/features/terminal-panel/mobile/long-press-copy-line.test.ts

@@ -57,7 +57,6 @@ function createRowsDom() {
 
   return {
     rows,
-    firstTarget: firstRow.querySelector("span") as HTMLSpanElement,
     secondTarget: secondRow.querySelector("span span") as HTMLSpanElement,
     thirdTarget: thirdRow.querySelector("span span") as HTMLSpanElement,
   };
@@ -109,6 +108,28 @@ describe("getLogicalLineTextFromTouchTarget", () => {
     rows.remove();
   });
 
+  it("returns null when the mapped buffer row is missing", () => {
+    const { rows, secondTarget } = createRowsDom();
+    document.body.appendChild(rows);
+
+    const terminal = createTerminal(40, [[40, createBufferLine("alpha")]]);
+
+    expect(getLogicalLineTextFromTouchTarget({ target: secondTarget, terminal })).toBeNull();
+
+    rows.remove();
+  });
+
+  it("returns null when a wrapped row's preceding segment is missing", () => {
+    const { rows, secondTarget } = createRowsDom();
+    document.body.appendChild(rows);
+
+    const terminal = createTerminal(50, [[51, createBufferLine("suffix   ", true)]]);
+
+    expect(getLogicalLineTextFromTouchTarget({ target: secondTarget, terminal })).toBeNull();
+
+    rows.remove();
+  });
+
   it("returns null when the touch target does not resolve to a direct xterm row", () => {
     const outside = document.createElement("div");
     outside.innerHTML = "<span>outside</span>";