Fix off-by-one bug in InsertClause handling; Add test case

Author: elifarley

src/cedarscript_editor/cedarscript_editor.py

@@ -138,8 +138,14 @@ def _update_command(self, cmd: UpdateCommand):
                 case _:
                     marker, search_range = find_marker_or_segment(action, lines, search_range)
                     match action:
-                        case InsertClause():
-                            search_range = search_range.set_line_count(0).inc()
+                        case InsertClause(insert_position=RelativeMarker(
+                            qualifier=qualifier)
+                        ):
+                            # TODO Handle BEFORE AFTER INSIDE_TOP INSIDE_BOTTOM
+                            search_range = search_range.set_line_count(0)
+                            if qualifier != RelativePositionType.AFTER:
+                                search_range = search_range.inc()
+
 
         match content:
             case str() | [str(), *_] | (str(), *_):

tests/corpus/update.identifier.insert.after.line/1.py

@@ -0,0 +1,2 @@
+def fun1(a, b):
+    return a + b

tests/corpus/update.identifier.insert.after.line/chat.xml

@@ -0,0 +1,14 @@
+<no-train>
+```CEDARScript
+UPDATE FUNCTION "fun1"
+FROM FILE "1.py"
+INSERT AFTER LINE "def fun1(a, b):"
+WITH CONTENT '''
+@1:"""Docstring...
+@0:
+@1:Args:
+@2:a
+@1:"""
+''';
+```
+</no-train>

tests/corpus/update.identifier.insert.after.line/expected.1.py

@@ -0,0 +1,7 @@
+def fun1(a, b):
+    """Docstring...
+
+    Args:
+        a
+    """
+    return a + b