clear empty list item on return

porcupine/plugins/markdown.py

@@ -15,14 +15,15 @@
 log = logging.getLogger(__name__)
 
 
-setup_before = ["tabs2spaces"]
+setup_before = ["tabs2spaces", "autoindent"]
 
 
 def _list_item(line: str) -> re.Match[str] | None:
     """Regex for markdown list item
 
-    First group is the whitespace (if any) preceding the item
-    Second group is the list item prefix (ex `-`, `+`, `6.`, `#.`)
+    1st group is the whitespace (if any) preceding the item
+    2nd group is the list item prefix (ex `-`, `+`, `6.`, `#.`)
+    3rd group is the item text
 
     According to:
     - https://spec.commonmark.org/0.30/#lists
@@ -36,7 +37,7 @@ def _list_item(line: str) -> re.Match[str] | None:
 
     assert len(line.splitlines()) == 1
 
-    list_item_regex = re.compile(r"(^[\t ]*)(\d{1,9}[.)]|[-+*]|#\)|#\.) .*")
+    list_item_regex = re.compile(r"(^[\t ]*)(\d{1,9}[.)]|[-+*]|#\)|#\.) (.*)")
     match = list_item_regex.search(line)
     return match if match else None
 
@@ -74,17 +75,34 @@ def continue_list(tab: tabs.FileTab, event: tkinter.Event[tkinter.Text]) -> str
         current_line = event.widget.get("insert - 1l linestart", "insert -1l lineend")
         list_item_match = _list_item(current_line)
         if list_item_match:
-            indentation, prefix = list_item_match.groups()
+            indentation, prefix, item_text = list_item_match.groups()
 
             tab.textwidget.insert("insert", prefix + " ")
             tab.update()
 
     return None
 
 
+def on_enter_press(tab: tabs.FileTab, event: tkinter.Event[tkinter.Text]) -> str | None:
+    if tab.settings.get("filetype_name", object) == "Markdown":
+        current_line = event.widget.get("insert linestart", "insert lineend")
+        list_item_match = _list_item(current_line)
+        if list_item_match:
+            indentation, prefix, item_text = list_item_match.groups()
+            if item_text:
+                # there is item text, so we are done here
+                return None
+
+            event.widget.delete("insert linestart", "insert lineend")
+            return "break"
+
+    return None
+
+
 def on_new_filetab(tab: tabs.FileTab) -> None:
     utils.bind_tab_key(tab.textwidget, partial(on_tab_key, tab), add=True)
     tab.textwidget.bind("<<post-autoindent>>", partial(continue_list, tab), add=True)
+    tab.textwidget.bind("<Return>", partial(on_enter_press, tab), add=True)
 
 
 def setup() -> None:

tests/test_markdown_plugin.py

@@ -198,8 +198,6 @@ def test_non_list(line: str, filetab, tmp_path):
 @pytest.mark.parametrize(
     "li",
     [
-        "- ",  # note the space
-        "1. ",  # note the space
         "1. item 1",
         "1) item 1",
         "#) item 1",
@@ -225,3 +223,35 @@ def test_list_continuation(li: str, filetab, tmp_path):
     filetab.update()
     current_line = filetab.textwidget.get("insert linestart", "insert lineend")
     assert markdown._list_item(current_line)
+
+
+@pytest.mark.parametrize("prefix", ["-", "+", "*", "#.", "#)", "1.", "1)", "88)", "88."])
+def test_return_remove_empty_item(prefix: str, filetab, tmp_path):
+    """Pressing 'return' on an empty item should remove it"""
+    filetab.textwidget.insert("1.0", prefix + " item 1")
+    filetab.update()
+
+    # switch to Markdown filetype format
+    filetab.save_as(tmp_path / "asdf.md")
+    assert filetab.settings.get("filetype_name", object) == "Markdown"
+
+    # new line
+    filetab.textwidget.event_generate("<Return>")
+    filetab.update()
+    previous_line = filetab.textwidget.get("insert - 1l linestart", "insert - 1l lineend")
+    current_line = filetab.textwidget.get("insert linestart", "insert lineend")
+    assert previous_line == f"{prefix} item 1"
+    assert markdown._list_item(previous_line)
+    assert current_line == f"{prefix} "
+    assert markdown._list_item(current_line)
+
+    # new line
+    filetab.textwidget.event_generate("<Return>")
+    filetab.update()
+    previous_line = filetab.textwidget.get("insert - 1l linestart", "insert - 1l lineend")
+    current_line = filetab.textwidget.get("insert linestart", "insert lineend")
+    assert previous_line == f"{prefix} item 1"
+    assert markdown._list_item(previous_line)
+    # current line should now be empty
+    assert current_line == ""
+    assert not markdown._list_item(current_line)