Merge pull request #3035 from pkch/dict-literals-for-typeddict

ilevkivskyi · web-flow · commit 6b93e63d9aef · 2017-03-31T23:44:31.000+02:00
Accept compatible dict in place of TypedDict
diff --git a/mypy/checkexpr.py b/mypy/checkexpr.py
@@ -1709,6 +1709,18 @@ def visit_dict_expr(self, e: DictExpr) -> Type:
 
         Translate it into a call to dict(), with provisions for **expr.
         """
+        # if the dict literal doesn't match TypedDict, check_typeddict_call_with_dict reports
+        # an error, but returns the TypedDict type that matches the literal it found
+        # that would cause a second error when that TypedDict type is returned upstream
+        # to avoid the second error, we always return TypedDict type that was requested
+        if isinstance(self.type_context[-1], TypedDictType):
+            self.check_typeddict_call_with_dict(
+                callee=self.type_context[-1],
+                kwargs=e,
+                context=e
+            )
+            return self.type_context[-1].copy_modified()
+
         # Collect function arguments, watching out for **expr.
         args = []  # type: List[Expression]  # Regular "key: value"
         stargs = []  # type: List[Expression]  # For "**expr"
diff --git a/test-data/unit/README.md b/test-data/unit/README.md
@@ -29,7 +29,10 @@ Add the test in this format anywhere in the file:
 - `# E: abc...` indicates that this line should result in type check error
 with text "abc..."
 - note a space after `E:` and `flags:`
-- lines without `# E: ` should cause no type check errors
+- `# E:12` adds column number to the expected error
+- repeating `# E: ` several times in one line indicates multiple expected errors in one line
+- `W: ...` and `N: ...` works exactly like `E:`, but report a warning and a note respectively
+- lines that don't contain the above should cause no type check errors
 - optional `[builtins fixtures/...]` tells the type checker to use
 stubs from the indicated file (see Fixtures section below)
 - optional `[out]` is an alternative to the "# E:" notation: it indicates that
diff --git a/test-data/unit/check-typeddict.test b/test-data/unit/check-typeddict.test
@@ -648,3 +648,42 @@ def f() -> None:
     A = TypedDict('A', {'x': int})
 A  # E: Name 'A' is not defined
 [builtins fixtures/dict.pyi]
+
+
+-- Use dict literals
+
+[case testTypedDictDictLiterals]
+from mypy_extensions import TypedDict
+
+Point = TypedDict('Point', {'x': int, 'y': int})
+
+def f(p: Point) -> None:
+    p = {'x': 2, 'y': 3}
+    p = {'x': 2}  # E: Expected items ['x', 'y'] but found ['x'].
+    p = dict(x=2, y=3)
+
+f({'x': 1, 'y': 3})
+f({'x': 1, 'y': 'z'})  # E: Incompatible types (expression has type "str", TypedDict item "y" has type "int")
+
+f(dict(x=1, y=3))
+f(dict(x=1, y=3, z=4))  # E: Expected items ['x', 'y'] but found ['x', 'y', 'z'].
+
+[builtins fixtures/dict.pyi]
+
+
+[case testTypedDictExplicitTypes]
+from mypy_extensions import TypedDict
+
+Point = TypedDict('Point', {'x': int, 'y': int})
+
+p1: Point = {'x': 'hi'}  # E: Expected items ['x', 'y'] but found ['x'].
+
+p2: Point
+p2 = dict(x='bye')  # E: Expected items ['x', 'y'] but found ['x'].
+
+p3 = Point(x=1, y=2)
+p3 = {'x': 'hi'}  # E: Expected items ['x', 'y'] but found ['x'].
+
+p4: Point = {'x': 1, 'y': 2}
+
+[builtins fixtures/dict.pyi]
