Added language to reflect the intended behavior for triple-quoted typ…

…e annotation expressions. (#1578)

* Added language to reflect the intended behavior for triple-quoted type annotation expressions.

* Updated conformance tests to include new rules for triple-quoted annotations.

conformance/results/mypy/annotations_forward_refs.toml

@@ -3,6 +3,7 @@ notes = """
 Does not report error for a forward reference that is not enclosed in quotes.
 Does not report error for use of quoted type with "|" operator (runtime error).
 Incorrectly generates error for quoted type defined in class scope.
+Does not treat triple-quoted forward reference annotation as implicitly parenthesized.
 """
 output = """
 annotations_forward_refs.py:41: error: Invalid type comment or annotation  [valid-type]
@@ -28,4 +29,5 @@ annotations_forward_refs.py:87: note: Perhaps you need "Callable[...]" or a call
 annotations_forward_refs.py:89: error: Function "annotations_forward_refs.ClassD.int" is not valid as a type  [valid-type]
 annotations_forward_refs.py:89: note: Perhaps you need "Callable[...]" or a callback protocol?
 annotations_forward_refs.py:93: error: Expression is of type int?, not "int"  [assert-type]
+annotations_forward_refs.py:100: error: Invalid type comment or annotation  [valid-type]
 """

conformance/results/mypy/version.toml

@@ -1,2 +1,2 @@
 version = "mypy 1.8.0"
-test_duration = 1.3906440734863281
+test_duration = 2.001461982727051

conformance/results/pyre/annotations_forward_refs.toml

@@ -5,6 +5,7 @@ Does not report error for use of quoted type with "|" operator (runtime error).
 Does not reject f-string in quoted type annotation.
 Incorrectly generates error for quoted type defined in class scope.
 Does not generate error for unquoted type defined in class scope.
+Does not treat triple-quoted forward reference annotation as implicitly parenthesized.
 """
 output = """
 annotations_forward_refs.py:19:25 Incompatible parameter type [6]: In call `typing.GenericMeta.__getitem__`, for 1st positional argument, expected `Type[Variable[_T]]` but got `UnionType`.
@@ -25,4 +26,5 @@ annotations_forward_refs.py:55:9 Undefined or invalid type [11]: Annotation `typ
 annotations_forward_refs.py:77:0 Uninitialized attribute [13]: Attribute `ClassC` is declared in class `ClassD` to have type `ClassC` but is never initialized.
 annotations_forward_refs.py:80:12 Undefined or invalid type [11]: Annotation `ClassF` is not defined as a type.
 annotations_forward_refs.py:87:7 Undefined or invalid type [11]: Annotation `ClassD.int` is not defined as a type.
+annotations_forward_refs.py:100:7 Undefined or invalid type [11]: Annotation `
 """

conformance/results/pyre/version.toml

@@ -1,2 +1,2 @@
 version = "pyre 0.9.19"
-test_duration = 2.216038227081299
+test_duration = 2.3505892753601074

conformance/results/pyright/version.toml

@@ -1,2 +1,2 @@
 version = "pyright 1.1.347"
-test_duration = 1.3326058387756348
+test_duration = 1.371502161026001

conformance/results/pytype/annotations_forward_refs.toml

@@ -3,6 +3,7 @@ notes = """
 Does not reject some illegal type expression forms when quoted.
 Incorrectly generates error for quoted type defined in class scope.
 Evaluates incorrect type for class variable annotated with quoted type expression.
+Does not treat triple-quoted forward reference annotation as implicitly parenthesized.
 """
 output = """
 File "annotations_forward_refs.py", line 22, in <module>: Name 'ClassA' is not defined [name-error]
@@ -42,4 +43,5 @@ File "annotations_forward_refs.py", line 89, in ClassD: Invalid type annotation
 File "annotations_forward_refs.py", line 93, in <module>: Any [assert-type]
   Expected: int
     Actual: Any
+File "annotations_forward_refs.py", line 100, in <module>: unexpected indent [python-compiler-error]
 """

conformance/results/pytype/version.toml

@@ -1,2 +1,2 @@
 version = "pytype 2023.12.18"
-test_duration = 27.246526956558228
+test_duration = 27.59779715538025

conformance/tests/annotations_forward_refs.py

@@ -91,3 +91,14 @@ def int(self) -> None:  # OK
 
 assert_type(ClassD.str, str)
 assert_type(ClassD.x, int)
+
+
+# > If a triple quote is used, the string should be parsed as though it is implicitly
+# > surrounded by parentheses. This allows newline characters to be
+# > used within the string literal.
+
+value: """
+    int |
+    str |
+    list[int]
+"""

docs/spec/annotations.rst

@@ -114,6 +114,16 @@ be evaluated.
 Moreover, the expression should be parseable as a valid type hint, i.e.,
 it is constrained by the rules from the section on :ref:`valid-types`.
 
+If a triple quote is used, the string should be parsed as though it is
+implicitly surrounded by parentheses. This allows newline characters to be 
+used within the string literal::
+
+    value: """
+        int |
+        str |
+        list[Any]
+    """
+
 It is allowable to use string literals as *part* of a type hint, for
 example::