test: add libghostty upgrade contract coverage

2 files changed, 115 insertions, 0 deletions

diff --git a/src/ghostty/mod.rs b/src/ghostty/mod.rs
index 75e600b8..99923789 100644
--- a/src/ghostty/mod.rs
+++ b/src/ghostty/mod.rs
@@ -1163,6 +1163,51 @@ mod tests {
         }
     }
 
+    fn build_info_bool(data: ffi::GhosttyBuildInfo) -> bool {
+        let mut out = false;
+        unsafe {
+            ffi::ghostty_build_info(data, (&mut out as *mut bool).cast())
+                .into_result()
+                .unwrap();
+        }
+        out
+    }
+
+    fn build_info_optimize() -> ffi::GhosttyOptimizeMode {
+        let mut out = ffi::GhosttyOptimizeMode_GHOSTTY_OPTIMIZE_DEBUG;
+        unsafe {
+            ffi::ghostty_build_info(
+                ffi::GhosttyBuildInfo_GHOSTTY_BUILD_INFO_OPTIMIZE,
+                (&mut out as *mut ffi::GhosttyOptimizeMode).cast(),
+            )
+            .into_result()
+            .unwrap();
+        }
+        out
+    }
+
+    #[test]
+    fn build_info_contract_matches_expected_vendored_features() {
+        let _simd = build_info_bool(ffi::GhosttyBuildInfo_GHOSTTY_BUILD_INFO_SIMD);
+        let _tmux_control_mode =
+            build_info_bool(ffi::GhosttyBuildInfo_GHOSTTY_BUILD_INFO_TMUX_CONTROL_MODE);
+        let kitty_graphics =
+            build_info_bool(ffi::GhosttyBuildInfo_GHOSTTY_BUILD_INFO_KITTY_GRAPHICS);
+        assert!(
+            !kitty_graphics,
+            "current herdr vendor must keep Kitty graphics disabled until image handling is explicit"
+        );
+
+        let optimize = build_info_optimize();
+        assert!(matches!(
+            optimize,
+            ffi::GhosttyOptimizeMode_GHOSTTY_OPTIMIZE_DEBUG
+                | ffi::GhosttyOptimizeMode_GHOSTTY_OPTIMIZE_RELEASE_SAFE
+                | ffi::GhosttyOptimizeMode_GHOSTTY_OPTIMIZE_RELEASE_SMALL
+                | ffi::GhosttyOptimizeMode_GHOSTTY_OPTIMIZE_RELEASE_FAST
+        ));
+    }
+
     #[test]
     fn focus_encoding_matches_expected_sequences() {
         assert_eq!(encode_focus(FocusEvent::Gained).unwrap(), b"\x1b[I");
@@ -1282,6 +1327,39 @@ mod tests {
     }
 
     #[test]
+    fn active_screen_and_cursor_visibility_contract() {
+        let mut terminal = Terminal::new(12, 3, 0).unwrap();
+        let mut render_state = RenderState::new().unwrap();
+
+        terminal.write(b"primary");
+        assert_eq!(terminal.active_screen().unwrap(), ActiveScreen::Primary);
+        assert_eq!(
+            terminal.read_text_viewport((0, 0), (6, 0), false).unwrap(),
+            "primary"
+        );
+
+        render_state.update(&terminal).unwrap();
+        assert_eq!(render_state.cursor_visible().unwrap(), true);
+        terminal.write(b"\x1b[?25l");
+        render_state.update(&terminal).unwrap();
+        assert_eq!(render_state.cursor_visible().unwrap(), false);
+
+        terminal.write(b"\x1b[?1049h\x1b[HALT");
+        assert_eq!(terminal.active_screen().unwrap(), ActiveScreen::Alternate);
+        assert_eq!(
+            terminal.read_text_viewport((0, 0), (2, 0), false).unwrap(),
+            "ALT"
+        );
+
+        terminal.write(b"\x1b[?1049l");
+        assert_eq!(terminal.active_screen().unwrap(), ActiveScreen::Primary);
+        assert_eq!(
+            terminal.read_text_viewport((0, 0), (6, 0), false).unwrap(),
+            "primary"
+        );
+    }
+
+    #[test]
     fn terminal_and_render_state_smoke_test() {
         let mut terminal = Terminal::new(8, 3, 100).unwrap();
         assert_eq!(terminal.cols().unwrap(), 8);
diff --git a/src/pane/terminal.rs b/src/pane/terminal.rs
index c688dcc9..c8f29b4c 100644
--- a/src/pane/terminal.rs
+++ b/src/pane/terminal.rs
@@ -972,6 +972,13 @@ mod tests {
         }
     }
 
+    fn write_wrapped_contract_lines(terminal: &mut crate::ghostty::Terminal, count: usize) {
+        for i in 0..count {
+            terminal.write(format!("WRAP-{i:03}-abcdefghijklmnopqrstuvwxyz\r\n").as_bytes());
+        }
+        terminal.write(b"END");
+    }
+
     #[test]
     fn host_terminal_theme_restore_probe_skips_when_no_transient_override() {
         let (tx, _rx) = mpsc::channel(4);
@@ -1363,6 +1370,36 @@ mod tests {
     }
 
     #[test]
+    fn resize_reflow_keeps_scrolled_viewport_and_bottom_detection_sane() {
+        let (tx, _rx) = mpsc::channel(4);
+        let mut terminal = crate::ghostty::Terminal::new(12, 4, 10_000).unwrap();
+        write_wrapped_contract_lines(&mut terminal, 40);
+        let pane = GhosttyPaneTerminal::new(terminal, tx).unwrap();
+
+        let bottom_snapshot = pane.detection_text();
+        assert!(bottom_snapshot.contains("END"));
+
+        let initial = pane.scroll_metrics().expect("initial scroll metrics");
+        assert!(initial.max_offset_from_bottom > 0);
+        pane.set_scroll_offset_from_bottom(initial.max_offset_from_bottom / 2);
+        assert!(!pane.visible_text().trim().is_empty());
+
+        for (rows, cols) in [(4, 10), (4, 7), (6, 18), (3, 9), (5, 12)] {
+            pane.resize(rows, cols);
+
+            let metrics = pane.scroll_metrics().expect("scroll metrics after resize");
+            assert_eq!(metrics.viewport_rows, rows as usize);
+            assert!(metrics.offset_from_bottom <= metrics.max_offset_from_bottom);
+            assert!(metrics.max_offset_from_bottom > 0);
+            assert!(!pane.visible_text().trim().is_empty());
+            assert!(
+                pane.detection_text().contains("END"),
+                "bottom detection should remain independent from the scrolled viewport after resize"
+            );
+        }
+    }
+
+    #[test]
     fn synchronized_output_suppresses_intermediate_render_requests_until_batch_ends() {
         let (tx, _rx) = mpsc::channel(4);
         let terminal = crate::ghostty::Terminal::new(80, 24, 0).unwrap();