Rename Red Knot (#17820)

crates/ty_python_semantic/resources/mdtest/invalid_syntax.md

@@ -0,0 +1,106 @@
+# Syntax errors
+
+Test cases to ensure that ty does not panic if there are syntax errors in the source code.
+
+The parser cannot recover from certain syntax errors completely which is why the number of syntax
+errors could be more than expected in the following examples. For instance, if there's a keyword
+(like `for`) in the middle of another statement (like function definition), then it's more likely
+that the rest of the tokens are going to be part of the `for` statement and not the function
+definition. But, it's not necessary that the remaining tokens are valid in the context of a `for`
+statement.
+
+## Keyword as identifiers
+
+When keywords are used as identifiers, the parser recovers from this syntax error by emitting an
+error and including the text value of the keyword to create the `Identifier` node.
+
+### Name expression
+
+#### Assignment
+
+```py
+# error: [invalid-syntax]
+pass = 1
+```
+
+#### Type alias
+
+```py
+# error: [invalid-syntax]
+# error: [invalid-syntax]
+type pass = 1
+```
+
+#### Function definition
+
+```py
+# error: [invalid-syntax]
+# error: [invalid-syntax]
+# error: [invalid-syntax]
+# error: [invalid-syntax]
+# error: [invalid-syntax]
+def True(for):
+    # error: [invalid-syntax]
+    # error: [invalid-syntax]
+    pass
+```
+
+#### For
+
+```py
+# error: [invalid-syntax]
+# error: [invalid-syntax]
+# error: [unresolved-reference] "Name `pass` used when not defined"
+for while in pass:
+    pass
+```
+
+#### While
+
+```py
+# error: [invalid-syntax]
+# error: [unresolved-reference] "Name `in` used when not defined"
+while in:
+    pass
+```
+
+#### Match
+
+```py
+# error: [invalid-syntax]
+# error: [invalid-syntax]
+# error: [unresolved-reference] "Name `match` used when not defined"
+match while:
+    # error: [invalid-syntax]
+    # error: [invalid-syntax]
+    # error: [invalid-syntax]
+    # error: [unresolved-reference] "Name `case` used when not defined"
+    case in:
+        # error: [invalid-syntax]
+        # error: [invalid-syntax]
+        pass
+```
+
+### Attribute expression
+
+```py
+# TODO: Check when support for attribute expressions is added
+
+# error: [invalid-syntax]
+# error: [unresolved-reference] "Name `foo` used when not defined"
+for x in foo.pass:
+    pass
+```
+
+## Invalid annotation
+
+### `typing.Callable`
+
+```py
+from typing import Callable
+
+# error: [invalid-syntax] "Expected index or slice expression"
+# error: [invalid-type-form] "Special form `typing.Callable` expected exactly two arguments (parameter types and return type)"
+def _(c: Callable[]):
+    reveal_type(c)  # revealed: (...) -> Unknown
+```