test: pin narrow-truncate re-measure parity with Ink

2026-05-28 16:36:30 +08:00
parent 4696b49313
commit 7b8ed05ef9
1 changed files with 19 additions and 0 deletions
@@ -18,3 +18,22 @@ test("multi-line truncate text keeps its line count (height)", async () => {
  expect(lines[0]).toBe("x");
  expect(lines[1]).toBe("yhello");
 });
+
+// Narrow truncate: when the text exceeds the box width, Ink re-measures the
+// wrapped text (so the node width shrinks to the truncated widest line) and
+// then truncates again at paint, yielding a doubly-truncated result. Verified
+// against real Ink (ink-testing-library): width=5 → ["x","…"]. This is
+// intentional Ink parity — do NOT "fix" it to one-pass truncation (["x","yh…"]).
+test("narrow truncate matches Ink's re-measure-then-truncate behavior", async () => {
+  const { lastFrame } = await render(
+    defineComponent(() => () => (
+      <Box width={5}>
+        <Text wrap="truncate">{"x\nyhello"}</Text>
+      </Box>
+    )),
+    { columns: 100 },
+  );
+  const lines = stripAnsi(lastFrame()!).split("\n");
+  expect(lines[0]).toBe("x");
+  expect(lines[1]).toBe("…");
+});