Add test_ipyext.py and fix a bug in julia_completer

Author: tkf

src/replhelper/ipyext.py

@@ -12,7 +12,7 @@ def _unregister_key_bindings():
 
 
 def julia_completer(julia, self, event):
-    pos = event.line.find("Main.eval")
+    pos = event.text_until_cursor.find("Main.eval")
     if pos < 0:
         return []
     pos += len("Main.eval('")  # pos: beginning of Julia code

src/replhelper/tests/test_ipyext.py

@@ -0,0 +1,51 @@
+import pytest
+
+from ..ipyext import julia_completer
+
+try:
+    from types import SimpleNamespace
+except ImportError:
+    from argparse import Namespace as SimpleNamespace
+
+try:
+    string_types = (unicode, str)
+except NameError:
+    string_types = (str,)
+
+
+def make_event(line, text_until_cursor=None, symbol=""):
+    if text_until_cursor is None:
+        text_until_cursor = line
+    return SimpleNamespace(
+        line=line,
+        text_until_cursor=text_until_cursor,
+        symbol=symbol,
+    )
+
+
+completable_events = [
+    make_event('Main.eval("'),
+    make_event('Main.eval("Base.'),
+]
+
+uncompletable_events = [
+    make_event(''),
+    make_event('Main.eval("', text_until_cursor="Main.e"),
+]
+
+
+@pytest.mark.parametrize("event", completable_events)
+def test_completable_events(julia, event):
+    dummy_ipython = None
+    completions = julia_completer(julia, dummy_ipython, event)
+    assert isinstance(completions, list)
+    assert completions
+    assert set(map(type, completions)) == set(string_types)
+
+
+@pytest.mark.parametrize("event", uncompletable_events)
+def test_uncompletable_events(julia, event):
+    dummy_ipython = None
+    completions = julia_completer(julia, dummy_ipython, event)
+    assert isinstance(completions, list)
+    assert not completions