Merge the FileNotFoundError cache.

jedi/parser/utils.py

@@ -10,6 +10,7 @@ import pickle
 
 from jedi import settings
 from jedi import debug
+from jedi._compatibility import FileNotFoundError
 
 
 def underscore_memoization(func):
@@ -128,12 +129,15 @@ class ParserPickling(object):
             # the pickle file is outdated
             return None
 
+        try:
             with open(self._get_hashed_path(grammar, path), 'rb') as f:
                 try:
                     gc.disable()
                     parser_cache_item = pickle.load(f)
                 finally:
                     gc.enable()
+        except FileNotFoundError:
+            return None
 
         debug.dbg('pickle loaded: %s', path)
         parser_cache[path] = parser_cache_item

test/test_cache.py

@@ -3,6 +3,7 @@ Test all things related to the ``jedi.cache`` module.
 """
 
 import time
+from os import unlink
 
 import pytest
 
@@ -65,6 +66,37 @@ def test_modulepickling_delete_incompatible_cache():
     assert cached2 is None
 
 
+@pytest.mark.usefixtures("isolated_jedi_cache")
+def test_modulepickling_simulate_deleted_cache():
+    """
+    Tests loading from a cache file after it is deleted.
+    According to macOS `dev docs`__,
+
+        Note that the system may delete the Caches/ directory to free up disk
+        space, so your app must be able to re-create or download these files as
+        needed.
+
+    It is possible that other supported platforms treat cache files the same
+    way.
+
+    __ https://developer.apple.com/library/content/documentation/FileManagement/Conceptual/FileSystemProgrammingGuide/FileSystemOverview/FileSystemOverview.html
+    """
+    item = ParserCacheItem('fake parser')
+    path = 'fake path'
+
+    cache = ParserPicklingCls()
+    cache.version = 1
+    grammar = load_grammar()
+    cache.save_parser(grammar, path, item)
+    cached1 = load_stored_item(grammar, cache, path, item)
+    assert cached1 == item.parser
+
+    unlink(cache._get_hashed_path(grammar, path))
+
+    cached2 = load_stored_item(grammar, cache, path, item)
+    assert cached2 is None
+
+
 @pytest.mark.skipif('True', message='Currently the star import cache is not enabled.')
 def test_star_import_cache_duration():
     new = 0.01