bpo-36419: IDLE - Refactor autocompete and improve testing. (#15121)

1 files changed, 49 insertions, 64 deletions

diff --git a/Lib/idlelib/autocomplete.py b/Lib/idlelib/autocomplete.py
index e20b757d871..c623d45a153 100644
--- a/Lib/idlelib/autocomplete.py
+++ b/Lib/idlelib/autocomplete.py
@@ -8,42 +8,45 @@ import os
 import string
 import sys
 
-# These constants represent the two different types of completions.
-# They must be defined here so autocomple_w can import them.
-COMPLETE_ATTRIBUTES, COMPLETE_FILES = range(1, 2+1)
-
+# Two types of completions; defined here for autocomplete_w import below.
+ATTRS, FILES = 0, 1
 from idlelib import autocomplete_w
 from idlelib.config import idleConf
 from idlelib.hyperparser import HyperParser
 
+# Tuples passed to open_completions.
+#       EvalFunc, Complete, WantWin, Mode
+FORCE = True,     False,    True,    None   # Control-Space.
+TAB   = False,    True,     True,    None   # Tab.
+TRY_A = False,    False,    False,   ATTRS  # '.' for attributes.
+TRY_F = False,    False,    False,   FILES  # '/' in quotes for file name.
+
 # This string includes all chars that may be in an identifier.
 # TODO Update this here and elsewhere.
 ID_CHARS = string.ascii_letters + string.digits + "_"
 
-SEPS = os.sep
-if os.altsep:  # e.g. '/' on Windows...
-    SEPS += os.altsep
-
+SEPS = f"{os.sep}{os.altsep if os.altsep else ''}"
+TRIGGERS = f".{SEPS}"
 
 class AutoComplete:
 
     def __init__(self, editwin=None):
         self.editwin = editwin
-        if editwin is not None:   # not in subprocess or test
+        if editwin is not None:   # not in subprocess or no-gui test
             self.text = editwin.text
-            self.autocompletewindow = None
-            # id of delayed call, and the index of the text insert when
-            # the delayed call was issued. If _delayed_completion_id is
-            # None, there is no delayed call.
-            self._delayed_completion_id = None
-            self._delayed_completion_index = None
+        self.autocompletewindow = None
+        # id of delayed call, and the index of the text insert when
+        # the delayed call was issued. If _delayed_completion_id is
+        # None, there is no delayed call.
+        self._delayed_completion_id = None
+        self._delayed_completion_index = None
 
     @classmethod
     def reload(cls):
         cls.popupwait = idleConf.GetOption(
             "extensions", "AutoComplete", "popupwait", type="int", default=0)
 
-    def _make_autocomplete_window(self):
+    def _make_autocomplete_window(self):  # Makes mocking easier.
         return autocomplete_w.AutoCompleteWindow(self.text)
 
     def _remove_autocomplete_window(self, event=None):
@@ -52,30 +55,12 @@ class AutoComplete:
             self.autocompletewindow = None
 
     def force_open_completions_event(self, event):
-        """Happens when the user really wants to open a completion list, even
-        if a function call is needed.
-        """
-        self.open_completions(True, False, True)
+        "(^space) Open completion list, even if a function call is needed."
+        self.open_completions(FORCE)
         return "break"
 
-    def try_open_completions_event(self, event):
-        """Happens when it would be nice to open a completion list, but not
-        really necessary, for example after a dot, so function
-        calls won't be made.
-        """
-        lastchar = self.text.get("insert-1c")
-        if lastchar == ".":
-            self._open_completions_later(False, False, False,
-                                         COMPLETE_ATTRIBUTES)
-        elif lastchar in SEPS:
-            self._open_completions_later(False, False, False,
-                                         COMPLETE_FILES)
-
     def autocomplete_event(self, event):
-        """Happens when the user wants to complete his word, and if necessary,
-        open a completion list after that (if there is more than one
-        completion)
-        """
+        "(tab) Complete word or open list if multiple options."
         if hasattr(event, "mc_state") and event.mc_state or\
                 not self.text.get("insert linestart", "insert").strip():
             # A modifier was pressed along with the tab or
@@ -85,34 +70,34 @@ class AutoComplete:
             self.autocompletewindow.complete()
             return "break"
         else:
-            opened = self.open_completions(False, True, True)
+            opened = self.open_completions(TAB)
             return "break" if opened else None
 
-    def _open_completions_later(self, *args):
-        self._delayed_completion_index = self.text.index("insert")
-        if self._delayed_completion_id is not None:
-            self.text.after_cancel(self._delayed_completion_id)
-        self._delayed_completion_id = \
-            self.text.after(self.popupwait, self._delayed_open_completions,
-                            *args)
-
-    def _delayed_open_completions(self, *args):
+    def try_open_completions_event(self, event=None):
+        "(./) Open completion list after pause with no movement."
+        lastchar = self.text.get("insert-1c")
+        if lastchar in TRIGGERS:
+            args = TRY_A if lastchar == "." else TRY_F
+            self._delayed_completion_index = self.text.index("insert")
+            if self._delayed_completion_id is not None:
+                self.text.after_cancel(self._delayed_completion_id)
+            self._delayed_completion_id = self.text.after(
+                self.popupwait, self._delayed_open_completions, args)
+
+    def _delayed_open_completions(self, args):
+        "Call open_completions if index unchanged."
         self._delayed_completion_id = None
         if self.text.index("insert") == self._delayed_completion_index:
-            self.open_completions(*args)
+            self.open_completions(args)
 
-    def open_completions(self, evalfuncs, complete, userWantsWin, mode=None):
+    def open_completions(self, args):
         """Find the completions and create the AutoCompleteWindow.
         Return True if successful (no syntax error or so found).
         If complete is True, then if there's nothing to complete and no
         start of completion, won't open completions and return False.
         If mode is given, will open a completion list only in this mode.
-
-        Action  Function                Eval   Complete WantWin Mode
-        ^space  force_open_completions  True,  False,   True    no
-        . or /  try_open_completions    False, False,   False   yes
-        tab     autocomplete            False, True,    True    no
         """
+        evalfuncs, complete, wantwin, mode = args
         # Cancel another delayed call, if it exists.
         if self._delayed_completion_id is not None:
             self.text.after_cancel(self._delayed_completion_id)
@@ -121,14 +106,14 @@ class AutoComplete:
         hp = HyperParser(self.editwin, "insert")
         curline = self.text.get("insert linestart", "insert")
         i = j = len(curline)
-        if hp.is_in_string() and (not mode or mode==COMPLETE_FILES):
+        if hp.is_in_string() and (not mode or mode==FILES):
             # Find the beginning of the string.
             # fetch_completions will look at the file system to determine
             # whether the string value constitutes an actual file name
             # XXX could consider raw strings here and unescape the string
             # value if it's not raw.
             self._remove_autocomplete_window()
-            mode = COMPLETE_FILES
+            mode = FILES
             # Find last separator or string start
             while i and curline[i-1] not in "'\"" + SEPS:
                 i -= 1
@@ -138,17 +123,17 @@ class AutoComplete:
             while i and curline[i-1] not in "'\"":
                 i -= 1
             comp_what = curline[i:j]
-        elif hp.is_in_code() and (not mode or mode==COMPLETE_ATTRIBUTES):
+        elif hp.is_in_code() and (not mode or mode==ATTRS):
             self._remove_autocomplete_window()
-            mode = COMPLETE_ATTRIBUTES
+            mode = ATTRS
             while i and (curline[i-1] in ID_CHARS or ord(curline[i-1]) > 127):
                 i -= 1
             comp_start = curline[i:j]
-            if i and curline[i-1] == '.':
+            if i and curline[i-1] == '.':  # Need object with attributes.
                 hp.set_index("insert-%dc" % (len(curline)-(i-1)))
                 comp_what = hp.get_expression()
-                if not comp_what or \
-                   (not evalfuncs and comp_what.find('(') != -1):
+                if (not comp_what or
+                   (not evalfuncs and comp_what.find('(') != -1)):
                     return None
             else:
                 comp_what = ""
@@ -163,7 +148,7 @@ class AutoComplete:
         self.autocompletewindow = self._make_autocomplete_window()
         return not self.autocompletewindow.show_window(
                 comp_lists, "insert-%dc" % len(comp_start),
-                complete, mode, userWantsWin)
+                complete, mode, wantwin)
 
     def fetch_completions(self, what, mode):
         """Return a pair of lists of completions for something. The first list
@@ -185,7 +170,7 @@ class AutoComplete:
             return rpcclt.remotecall("exec", "get_the_completion_list",
                                      (what, mode), {})
         else:
-            if mode == COMPLETE_ATTRIBUTES:
+            if mode == ATTRS:
                 if what == "":
                     namespace = {**__main__.__builtins__.__dict__,
                                  **__main__.__dict__}
@@ -207,7 +192,7 @@ class AutoComplete:
                     except:
                         return [], []
 
-            elif mode == COMPLETE_FILES:
+            elif mode == FILES:
                 if what == "":
                     what = "."
                 try: