fix(compatibility): git log and git diff with scrollup (#118)

* fix(compatibility): git log and git diff with scrollup

* style(formatting): make rustfmt happy

13 files changed, 364 insertions, 18 deletions

diff --git a/src/terminal_pane/scroll.rs b/src/terminal_pane/scroll.rs
index 20f98da0..6301c7c1 100644
--- a/src/terminal_pane/scroll.rs
+++ b/src/terminal_pane/scroll.rs
@@ -661,7 +661,7 @@ impl Scroll {
     pub fn move_current_buffer_to_alternative_buffer(&mut self) {
         self.alternative_buffer = Some(self.canonical_lines.drain(..).collect());
         self.alternative_cursor_position = Some(self.cursor_position);
-        self.cursor_position.reset();
+        self.clear_all();
     }
     pub fn override_current_buffer_with_alternative_buffer(&mut self) {
         if let Some(alternative_buffer) = self.alternative_buffer.as_mut() {
@@ -691,6 +691,19 @@ impl Scroll {
             Some((self.scroll_region.unwrap().0, self.scroll_region.unwrap().1))
         }
     }
+    fn scroll_region_absolute_indices_or_screen_edges(&mut self) -> (usize, usize) {
+        match self.scroll_region {
+            Some(_scroll_region) => self.scroll_region_absolute_indices().unwrap(),
+            None => {
+                // indices of screen top and bottom edge
+                // TODO: what if we don't have enough lines?
+                // let absolute_top = self.canonical_lines.len() - 1 - self.lines_in_view;
+                let absolute_top = self.canonical_lines.len() - self.lines_in_view;
+                let absolute_bottom = self.canonical_lines.len() - 1;
+                (absolute_top, absolute_bottom)
+            }
+        }
+    }
     pub fn delete_lines_in_scroll_region(&mut self, count: usize) {
         if let Some((scroll_region_top, scroll_region_bottom)) =
             self.scroll_region_absolute_indices()
@@ -732,23 +745,20 @@ impl Scroll {
         }
     }
     pub fn move_cursor_up_in_scroll_region(&mut self, count: usize) {
-        if let Some((scroll_region_top, scroll_region_bottom)) =
-            self.scroll_region_absolute_indices()
-        {
-            // the scroll region indices start at 1, so we need to adjust them
-            for _ in 0..count {
-                let current_canonical_line_index = self.cursor_position.line_index.0;
-                if current_canonical_line_index == scroll_region_top {
-                    // if we're at the top line, we create a new line and remove the last line that
-                    // would otherwise overflow
-                    self.canonical_lines.remove(scroll_region_bottom);
-                    self.canonical_lines
-                        .insert(current_canonical_line_index, CanonicalLine::new());
-                } else if current_canonical_line_index > scroll_region_top
-                    && current_canonical_line_index <= scroll_region_bottom
-                {
-                    self.move_cursor_up(count);
-                }
+        let (scroll_region_top, scroll_region_bottom) =
+            self.scroll_region_absolute_indices_or_screen_edges();
+        for _ in 0..count {
+            let current_canonical_line_index = self.cursor_position.line_index.0;
+            if current_canonical_line_index == scroll_region_top {
+                // if we're at the top line, we create a new line and remove the last line that
+                // would otherwise overflow
+                self.canonical_lines.remove(scroll_region_bottom);
+                self.canonical_lines
+                    .insert(current_canonical_line_index, CanonicalLine::new());
+            } else if current_canonical_line_index > scroll_region_top
+                && current_canonical_line_index <= scroll_region_bottom
+            {
+                self.move_cursor_up(count);
             }
         }
     }
diff --git a/src/tests/fixtures/git_diff_scrollup b/src/tests/fixtures/git_diff_scrollup
new file mode 100644
index 00000000..98d06baa
--- /dev/null
+++ b/src/tests/fixtures/git_diff_scrollup
diff --git a/src/tests/fixtures/git_log b/src/tests/fixtures/git_log
new file mode 100644
index 00000000..9b5bca62
--- /dev/null
+++ b/src/tests/fixtures/git_log
diff --git a/src/tests/integration/compatibility.rs b/src/tests/integration/compatibility.rs
index 578e8fd2..e42a26fb 100644
--- a/src/tests/integration/compatibility.rs
+++ b/src/tests/integration/compatibility.rs
@@ -413,3 +413,51 @@ pub fn fish_paste_multiline() {
         assert_snapshot!(snapshot);
     }
 }
+
+#[test]
+pub fn git_log() {
+    let fake_win_size = PositionAndSize {
+        columns: 149,
+        rows: 28,
+        x: 0,
+        y: 0,
+    };
+    let fixture_name = "git_log";
+    let mut fake_input_output = get_fake_os_input(&fake_win_size, fixture_name);
+    fake_input_output.add_terminal_input(&[&COMMAND_TOGGLE, &COMMAND_TOGGLE, &QUIT]);
+    start(Box::new(fake_input_output.clone()), Opt::default());
+    let output_frames = fake_input_output
+        .stdout_writer
+        .output_frames
+        .lock()
+        .unwrap();
+    let snapshots = get_output_frame_snapshots(&output_frames, &fake_win_size);
+    for snapshot in snapshots {
+        assert_snapshot!(snapshot);
+    }
+}
+
+#[test]
+pub fn git_diff_scrollup() {
+    // this tests makes sure that when we have a git diff that exceeds the screen size
+    // we are able to scroll up
+    let fake_win_size = PositionAndSize {
+        columns: 149,
+        rows: 28,
+        x: 0,
+        y: 0,
+    };
+    let fixture_name = "git_diff_scrollup";
+    let mut fake_input_output = get_fake_os_input(&fake_win_size, fixture_name);
+    fake_input_output.add_terminal_input(&[&COMMAND_TOGGLE, &COMMAND_TOGGLE, &QUIT]);
+    start(Box::new(fake_input_output.clone()), Opt::default());
+    let output_frames = fake_input_output
+        .stdout_writer
+        .output_frames
+        .lock()
+        .unwrap();
+    let snapshots = get_output_frame_snapshots(&output_frames, &fake_win_size);
+    for snapshot in snapshots {
+        assert_snapshot!(snapshot);
+    }
+}
diff --git a/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_diff-2.snap b/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_diff-2.snap
new file mode 100644
index 00000000..53a568d5
--- /dev/null
+++ b/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_diff-2.snap
@@ -0,0 +1,32 @@
+---
+source: src/tests/integration/compatibility.rs
+expression: snapshot
+---
+                                                                                                                                                     
+    * wip: doesn't render when new tab is created?                                                                                                   
+                                                                                                                                                     
+    * wip: doesnt re-render when a new tab is spawned for now                                                                                        
+                                                                                                                                                     
+    * wip: tabs now are a BTreeMap and we can switch between them in both directions                                                                 
+                                                                                                                                                     
+    * wip: I think that should also be here                                                                                                          
+                                                                                                                                                     
+    * wip: cleanup                                                                                                                                   
+                                                                                                                                                     
+    * Spawn a new terminal simultaneously with a new tab                                                                                             
+                                                                                                                                                     
+    * Ensure proper Opening and Closing of tabs                                                                                                      
+                                                                                                                                                     
+    * cleanup                                                                                                                                        
+                                                                                                                                                     
+    * more cleanup                                                                                                                                   
+                                                                                                                                                     
+    * tests(snapshots): add 'loading' snapshot to each scenario                                                                                      
+                                                                                                                                                     
+    * fix(tests): update snapshots                                                                                                                   
+                                                                                                                                                     
+    * Add tests for tabs implementation                                                                                                              
+                                                                                                                                                     
+    * wip: added tests, moved tab related stuff to a separate file                                                                                   
+                                                                                                                                                     
+:█                                                                                                                                                   
diff --git a/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_diff-3.snap b/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_diff-3.snap
new file mode 100644
index 00000000..e50d9493
--- /dev/null
+++ b/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_diff-3.snap
@@ -0,0 +1,32 @@
+---
+source: src/tests/integration/compatibility.rs
+expression: snapshot
+---
+    * wip: doesn't render when new tab is created?                                                                                                   
+                                                                                                                                                     
+    * wip: doesnt re-render when a new tab is spawned for now                                                                                        
+                                                                                                                                                     
+    * wip: tabs now are a BTreeMap and we can switch between them in both directions                                                                 
+                                                                                                                                                     
+    * wip: I think that should also be here                                                                                                          
+                                                                                                                                                     
+    * wip: cleanup                                                                                                                                   
+                                                                                                                                                     
+    * Spawn a new terminal simultaneously with a new tab                                                                                             
+                                                                                                                                                     
+    * Ensure proper Opening and Closing of tabs                                                                                                      
+                                                                                                                                                     
+    * cleanup                                                                                                                                        
+                                                                                                                                                     
+    * more cleanup                                                                                                                                   
+                                                                                                                                                     
+    * tests(snapshots): add 'loading' snapshot to each scenario                                                                                      
+                                                                                                                                                     
+    * fix(tests): update snapshots                                                                                                                   
+                                                                                                                                                     
+    * Add tests for tabs implementation                                                                                                              
+                                                                                                                                                     
+    * wip: added tests, moved tab related stuff to a separate file                                                                                   
+                                                                                                                                                     
+:                                                                                                                                                    
+Bye from Mosaic!█                                                                                                                                    
diff --git a/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_diff.snap b/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_diff.snap
new file mode 100644
index 00000000..739c38e6
--- /dev/null
+++ b/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_diff.snap
@@ -0,0 +1,32 @@
+---
+source: src/tests/integration/compatibility.rs
+expression: snapshot
+---
+█                                                                                                                                                    
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
diff --git a/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_diff_scrollup-2.snap b/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_diff_scrollup-2.snap
new file mode 100644
index 00000000..e1f541c2
--- /dev/null
+++ b/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_diff_scrollup-2.snap
@@ -0,0 +1,32 @@
+---
+source: src/tests/integration/compatibility.rs
+expression: snapshot
+---
+                                                                                                                                                     
+src/terminal_pane/scroll.rs                                                                                                                          
+───────────────────────────────────────────────────────────────────────────────────────────────────────────────────                                  
+                                                                                                                                                     
+────────────────────────────────────────────────┐                                                                                                    
+use crate::terminal_pane::terminal_character::{ │                                                                                                    
+────────────────────────────────────────────────┘                                                                                                    
+5                                                                                                                                                    
+    CharacterStyles, TerminalCharacter, EMPTY_TERMINAL_CHARACTER,                                                                                    
+};                                                                                                                                                   
+                                                                                                                                                     
+use crate::utils::logging::debug_log_to_file;                                                                                                        
+                                                                                                                                                     
+/*                                                                                                                                                   
+ * Scroll                                                                                                                                            
+ *                                                                                                                                                   
+                                                                                                                                                     
+──────────────┐                                                                                                                                      
+impl Scroll { │                                                                                                                                      
+──────────────┘                                                                                                                                      
+663                                                                                                                                                  
+    pub fn move_current_buffer_to_alternative_buffer(&mut self) {                                                                                    
+        self.alternative_buffer = Some(self.canonical_lines.drain(..).collect());                                                                    
+        self.alternative_cursor_position = Some(self.cursor_position);                                                                               
+        self.cursor_position.reset();                                                                                                                
+        self.clear_all();                                                                                                                            
+    }                                                                                                                                                
+:█                                                                                                                                                   
diff --git a/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_diff_scrollup-3.snap b/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_diff_scrollup-3.snap
new file mode 100644
index 00000000..ba0e26d4
--- /dev/null
+++ b/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_diff_scrollup-3.snap
@@ -0,0 +1,32 @@
+---
+source: src/tests/integration/compatibility.rs
+expression: snapshot
+---
+src/terminal_pane/scroll.rs                                                                                                                          
+───────────────────────────────────────────────────────────────────────────────────────────────────────────────────                                  
+                                                                                                                                                     
+────────────────────────────────────────────────┐                                                                                                    
+use crate::terminal_pane::terminal_character::{ │                                                                                                    
+────────────────────────────────────────────────┘                                                                                                    
+5                                                                                                                                                    
+    CharacterStyles, TerminalCharacter, EMPTY_TERMINAL_CHARACTER,                                                                                    
+};                                                                                                                                                   
+                                                                                                                                                     
+use crate::utils::logging::debug_log_to_file;                                                                                                        
+                                                                                                                                                     
+/*                                                                                                                                                   
+ * Scroll                                                                                                                                            
+ *                                                                                                                                                   
+                                                                                                                                                     
+──────────────┐                                                                                                                                      
+impl Scroll { │                                                                                                                                      
+──────────────┘                                                                                                                                      
+663                                                                                                                                                  
+    pub fn move_current_buffer_to_alternative_buffer(&mut self) {                                                                                    
+        self.alternative_buffer = Some(self.canonical_lines.drain(..).collect());                                                                    
+        self.alternative_cursor_position = Some(self.cursor_position);                                                                               
+        self.cursor_position.reset();                                                                                                                
+        self.clear_all();                                                                                                                            
+    }                                                                                                                                                
+:                                                                                                                                                    
+Bye from Mosaic!█                                                                                                                                    
diff --git a/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_diff_scrollup.snap b/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_diff_scrollup.snap
new file mode 100644
index 00000000..739c38e6
--- /dev/null
+++ b/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_diff_scrollup.snap
@@ -0,0 +1,32 @@
+---
+source: src/tests/integration/compatibility.rs
+expression: snapshot
+---
+█                                                                                                                                                    
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
diff --git a/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_log-2.snap b/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_log-2.snap
new file mode 100644
index 00000000..53a568d5
--- /dev/null
+++ b/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_log-2.snap
@@ -0,0 +1,32 @@
+---
+source: src/tests/integration/compatibility.rs
+expression: snapshot
+---
+                                                                                                                                                     
+    * wip: doesn't render when new tab is created?                                                                                                   
+                                                                                                                                                     
+    * wip: doesnt re-render when a new tab is spawned for now                                                                                        
+                                                                                                                                                     
+    * wip: tabs now are a BTreeMap and we can switch between them in both directions                                                                 
+                                                                                                                                                     
+    * wip: I think that should also be here                                                                                                          
+                                                                                                                                                     
+    * wip: cleanup                                                                                                                                   
+                                                                                                                                                     
+    * Spawn a new terminal simultaneously with a new tab                                                                                             
+                                                                                                                                                     
+    * Ensure proper Opening and Closing of tabs                                                                                                      
+                                                                                                                                                     
+    * cleanup                                                                                                                                        
+                                                                                                                                                     
+    * more cleanup                                                                                                                                   
+                                                                                                                                                     
+    * tests(snapshots): add 'loading' snapshot to each scenario                                                                                      
+                                                                                                                                                     
+    * fix(tests): update snapshots                                                                                                                   
+                                                                                                                                                     
+    * Add tests for tabs implementation                                                                                                              
+                                                                                                                                                     
+    * wip: added tests, moved tab related stuff to a separate file                                                                                   
+                                                                                                                                                     
+:█                                                                                                                                                   
diff --git a/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_log-3.snap b/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_log-3.snap
new file mode 100644
index 00000000..e50d9493
--- /dev/null
+++ b/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_log-3.snap
@@ -0,0 +1,32 @@
+---
+source: src/tests/integration/compatibility.rs
+expression: snapshot
+---
+    * wip: doesn't render when new tab is created?                                                                                                   
+                                                                                                                                                     
+    * wip: doesnt re-render when a new tab is spawned for now                                                                                        
+                                                                                                                                                     
+    * wip: tabs now are a BTreeMap and we can switch between them in both directions                                                                 
+                                                                                                                                                     
+    * wip: I think that should also be here                                                                                                          
+                                                                                                                                                     
+    * wip: cleanup                                                                                                                                   
+                                                                                                                                                     
+    * Spawn a new terminal simultaneously with a new tab                                                                                             
+                                                                                                                                                     
+    * Ensure proper Opening and Closing of tabs                                                                                                      
+                                                                                                                                                     
+    * cleanup                                                                                                                                        
+                                                                                                                                                     
+    * more cleanup                                                                                                                                   
+                                                                                                                                                     
+    * tests(snapshots): add 'loading' snapshot to each scenario                                                                                      
+                                                                                                                                                     
+    * fix(tests): update snapshots                                                                                                                   
+                                                                                                                                                     
+    * Add tests for tabs implementation                                                                                                              
+                                                                                                                                                     
+    * wip: added tests, moved tab related stuff to a separate file                                                                                   
+                                                                                                                                                     
+:                                                                                                                                                    
+Bye from Mosaic!█                                                                                                                                    
diff --git a/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_log.snap b/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_log.snap
new file mode 100644
index 00000000..739c38e6
--- /dev/null
+++ b/src/tests/integration/snapshots/mosaic__tests__integration__compatibility__git_log.snap
@@ -0,0 +1,32 @@
+---
+source: src/tests/integration/compatibility.rs
+expression: snapshot
+---
+█                                                                                                                                                    
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+                                                                                                                                                     
+