Sort completions by input resemblance.

Fixes #2017

AUTHORS.txt

@@ -65,6 +65,7 @@ Code Contributors
 - Márcio Mazza (@marciomazza)
 - Martin Vielsmaier (@moser) <[email protected]>
 - TingJia Wu (@WutingjiaX) <[email protected]>
+- Nguyễn Hồng Quân <[email protected]>
 
 And a few more "anonymous" contributors.
 

jedi/api/completion.py

@@ -138,6 +138,11 @@ def __init__(self, inference_state, module_context, code_lines, position,
 
         self._fuzzy = fuzzy
 
+    # Return list of completions in this order:
+    # - Beginning with what user is typing
+    # - Public (alphabet)
+    # - Private ("_xxx")
+    # - Dunder ("__xxx")
     def complete(self):
         leaf = self._module_node.get_leaf_for_position(
             self._original_position,
@@ -176,7 +181,8 @@ def complete(self):
         return (
             # Removing duplicates mostly to remove False/True/None duplicates.
             _remove_duplicates(prefixed_completions, completions)
-            + sorted(completions, key=lambda x: (x.name.startswith('__'),
+            + sorted(completions, key=lambda x: (not x.name.startswith(self._like_name), 
+                                                 x.name.startswith('__'),
                                                  x.name.startswith('_'),
                                                  x.name.lower()))
         )

test/test_api/test_api.py

@@ -321,10 +321,19 @@ def test_docstrings_for_completions(Script):
         assert isinstance(c.docstring(), str)
 
 
+def test_completions_order_most_resemblance_on_top(Script):
+    """Test that the completion which resembles the in-typing the most will come first."""
+    code = "from pathlib import Path\npath = Path('hello.txt')\n\npat"
+    script = Script(code)
+    # User is typing "pat" and "path" is closer to it than "Path".
+    assert ['path', 'Path'] == [comp.name for comp in script.complete()]
+
+
 def test_fuzzy_completion(Script):
     script = Script('string =  "hello"\nstring.upper')
-    assert ['isupper',
-            'upper'] == [comp.name for comp in script.complete(fuzzy=True)]
+    # 'isupper' is included because it is fuzzily matched.
+    assert ['upper',
+            'isupper'] == [comp.name for comp in script.complete(fuzzy=True)]
 
 
 def test_math_fuzzy_completion(Script, environment):