fix: remove orphaned cells (#73)

rplugin/python3/molten/__init__.py

@@ -701,7 +701,9 @@ def command_export(self, args, bang: bool) -> None:
         if len(args) > 1:
             kernel = args[1]
         else:
-            self.kernel_check(f"MoltenExportOutput{'!' if bang else ''}", path, buf, kernel_last=True)
+            self.kernel_check(
+                f"MoltenExportOutput{'!' if bang else ''}", path, buf, kernel_last=True
+            )
             return
 
         kernels = self._get_current_buf_kernels(True)

rplugin/python3/molten/code_cell.py

@@ -48,6 +48,9 @@ def clear_interface(self, highlight_namespace):
             self.end.lineno + 1,
         )
 
+    def empty(self) -> bool:
+        return self.end <= self.begin
+
     def get_text(self, nvim: Nvim) -> str:
         assert self.begin.bufno == self.end.bufno
 

rplugin/python3/molten/moltenbuffer.py

@@ -15,9 +15,10 @@
 from molten.runtime import JupyterRuntime
 
 
-# Handles a Single Kernel that can be attached to multiple buffers
-# Other MoltenKernels can be attached to the same buffers
 class MoltenKernel:
+    """Handles a Single Kernel that can be attached to multiple buffers
+    Other MoltenKernels can be attached to the same buffers"""
+
     nvim: Nvim
     canvas: Canvas
     highlight_namespace: int
@@ -26,8 +27,8 @@ class MoltenKernel:
 
     runtime: JupyterRuntime
 
-    # name unique to this specific jupyter runtime. Only used within Molten. Human Readable
     kernel_id: str
+    """name unique to this specific jupyter runtime. Only used within Molten. Human Readable"""
 
     outputs: Dict[CodeCell, OutputBuffer]
     current_output: Optional[CodeCell]
@@ -210,6 +211,14 @@ def delete_cell(self) -> None:
         del self.outputs[self.selected_cell]
         self.selected_cell = None
 
+    def clear_empty_spans(self) -> None:
+        for span in list(self.outputs.keys()):
+            if span.empty():
+                self.outputs[span].clear_float_win()
+                self.outputs[span].clear_virt_output(span.bufno)
+                del self.outputs[span]
+                span.clear_interface(self.highlight_namespace)
+
     def update_interface(self) -> None:
         buffer_numbers = [buf.number for buf in self.buffers]
         if self.nvim.current.buffer.number not in buffer_numbers:
@@ -219,6 +228,7 @@ def update_interface(self) -> None:
             return
 
         self.updating_interface = True
+        self.clear_empty_spans()
         new_selected_cell = self._get_selected_span()
 
         # Clear the cell we just left