More tests and better understanding of if/try branches name resolution.

jedi/evaluate/filters.py

@@ -155,13 +155,18 @@ class ParserTreeFilter(AbstractUsedNamesFilter):
 
     def _filter(self, names):
         names = super(ParserTreeFilter, self)._filter(names)
-        names = [n for n in names if n.is_definition() and n.parent.type != 'trailer']
-        names = [n for n in names
-                 if ((n.parent if n.parent.type in ('classdef', 'funcdef') else n)
-                        .get_parent_scope() == self._parser_scope)]
-
+        names = [n for n in names if self._is_name_reachable(n)]
         return list(self._check_flows(names))
 
+    def _is_name_reachable(self, name):
+        if not name.is_definition():
+            return False
+        parent = name.parent
+        if parent.type == 'trailer':
+            return False
+        base_node = parent if parent.type in ('classdef', 'funcdef') else name
+        return base_node.get_parent_scope() == self._parser_scope
+
     def _check_flows(self, names):
         for name in sorted(names, key=lambda name: name.start_pos, reverse=True):
             check = flow_analysis.reachability_check(

jedi/evaluate/flow_analysis.py

@@ -32,19 +32,46 @@ UNREACHABLE = Status(False, 'unreachable')
 UNSURE = Status(None, 'unsure')
 
 
+def _get_flow_scopes(node):
+    while True:
+        node = node.get_parent_scope(include_flows=True)
+        if node.type in ('funcdef', 'classdef', 'file_input'):
+            return
+        yield node
+
+
 def reachability_check(context, context_scope, node, origin_scope=None):
     flow_scope = node.get_parent_scope(include_flows=True)
-    # Direct parents get resolved, we filter scopes that are separate branches.
-    # This makes sense for autocompletion and static analysis. For actual
-    # Python it doesn't matter, because we're talking about potentially
-    # unreachable code.
-    # e.g. `if 0:` would cause all name lookup within the flow make
-    # unaccessible. This is not a "problem" in Python, because the code is
-    # never called. In Jedi though, we still want to infer types.
-    #while origin_scope is not None:
-        #if flow_scope == origin_scope:
-            #return REACHABLE
-        #origin_scope = origin_scope.parent
+    if origin_scope is not None:
+        origin_flow_scopes = list(_get_flow_scopes(origin_scope))
+        node_flow_scopes = list(_get_flow_scopes(node))
+
+        branch_matches = True
+        for flow_scope in origin_flow_scopes:
+            if flow_scope in node_flow_scopes:
+                node_keyword = flow_scope.get_branch_keyword(node)
+                origin_keyword = flow_scope.get_branch_keyword(origin_scope)
+                branch_matches = node_keyword == origin_keyword
+                if flow_scope.type == 'if_stmt':
+                    if not branch_matches:
+                        return UNREACHABLE
+                elif flow_scope.type == 'try_stmt':
+                    if not branch_matches and origin_keyword == 'else' \
+                            and node_keyword == 'except':
+                        return UNREACHABLE
+                break
+
+        # Direct parents get resolved, we filter scopes that are separate
+        # branches.  This makes sense for autocompletion and static analysis.
+        # For actual Python it doesn't matter, because we're talking about
+        # potentially unreachable code.
+        # e.g. `if 0:` would cause all name lookup within the flow make
+        # unaccessible. This is not a "problem" in Python, because the code is
+        # never called. In Jedi though, we still want to infer types.
+        while origin_scope is not None:
+            if flow_scope == origin_scope and branch_matches:
+                return REACHABLE
+            origin_scope = origin_scope.parent
 
     return _break_check(context, context_scope, flow_scope, node)
 

jedi/evaluate/stdlib.py

@@ -179,10 +179,13 @@ def builtins_isinstance(evaluator, objects, types, arguments):
         for cls_or_tup in types:
             if cls_or_tup.is_class():
                 bool_results.add(cls_or_tup in mro)
-            elif str(cls_or_tup.name) == 'tuple' \
-                    and cls_or_tup.get_parent_scope() == evaluator.BUILTINS:
+            elif cls_or_tup.name.string_name == 'tuple' \
+                    and cls_or_tup.get_root_context() == evaluator.BUILTINS:
                 # Check for tuples.
-                classes = unite(cls_or_tup.py__iter__())
+                classes = unite(
+                    lazy_context.infer()
+                    for lazy_context in cls_or_tup.py__iter__()
+                )
                 bool_results.add(any(cls in mro for cls in classes))
             else:
                 _, lazy_context = list(arguments.unpack())[1]

jedi/parser/tree.py

@@ -1134,12 +1134,29 @@ class Lambda(Function):
 
 class Flow(BaseNode):
     __slots__ = ()
+    FLOW_KEYWORDS = (
+        'try', 'except', 'finally', 'else', 'if', 'elif', 'with', 'for', 'while'
+    )
 
     def nodes_to_execute(self, last_added=False):
         for child in self.children:
             for node_to_execute in child.nodes_to_execute():
                 yield node_to_execute
 
+    def get_branch_keyword(self, node):
+        start_pos = node.start_pos
+        if not (self.start_pos < start_pos <= self.end_pos):
+            raise ValueError('The node is not part of the flow.')
+
+        keyword = None
+        for i, child in enumerate(self.children):
+            if start_pos < child.start_pos:
+                return keyword
+            first_leaf = child.first_leaf()
+            if first_leaf in self.FLOW_KEYWORDS:
+                keyword = first_leaf
+        return 0
+
 
 class IfStmt(Flow):
     type = 'if_stmt'

test/completion/flow_analysis.py

@@ -1,3 +1,39 @@
+# -----------------
+# First a few name resolution things
+# -----------------
+
+x = 3
+if NOT_DEFINED:
+    x = ''
+#? 6 int()
+elif x:
+    pass
+else:
+    #? int()
+    x
+
+x = 1
+try:
+    x = ''
+#? 8 int() str()
+except x:
+    #? 5 int() str()
+    x
+    x = 1.0
+else:
+    #? 5 int() str()
+    x
+    x = list
+finally:
+    #? 5 int() str() float() list
+    x
+    x = tuple
+
+
+# -----------------
+# Return checks
+# -----------------
+
 def foo(x):
     if 1.0:
         return 1