Function TestPromptAutoGrowsWithContent

internal/tui/tui_test.go:2388–2409

TestPromptAutoGrowsWithContent: the textarea starts at 1 line, grows with newlines, and clamps to height - minViewport - 2 - popover, so big pastes use most of the screen while chat keeps its floor.

(t *testing.T)

		width    int
		wantRows int
	}{
		{"empty", "", 15, 1},
		{"short fits", "hello", 15, 1},
		{"short with spaces fits", "hi you", 15, 1},
		{"exactly fills width adds cursor anchor", strings.Repeat("x", 15), 15, 2},
		{"just under width", strings.Repeat("x", 14), 15, 1},
		{"just over width hard-wraps", strings.Repeat("x", 16), 15, 2},
		{"long hard-wrap no spaces", strings.Repeat("x", 45), 15, 4},
		{"word-boundary wastes space", strings.Repeat("hello ", 20), 15, 10},
		{"zero width floors to 1", "anything", 0, 1},
	}
	for _, c := range cases {
		if got := wrapRows(c.input, c.width); got != c.wantRows {
			t.Errorf("wrapRows(%q, %d) = %d, want %d", c.input, c.width, got, c.wantRows)
		}
	}
}

// TestVisualPromptLinesSumsAcrossLogicalLines: visualPromptLines splits on
// newlines and sums wrapRows for each segment: the prompt field grows to
// hold the combined visual height.
func TestVisualPromptLinesSumsAcrossLogicalLines(t *testing.T) {
	m := newTestModel(t, func(http.ResponseWriter, *http.Request) {})
	// width=100, effective=96. Two short logical lines = 2 visual rows.
	m.ta.SetValue("first line\nsecond line")