adds dataclass argument type test cases

mypy/plugins/dataclasses.py

@@ -4,7 +4,7 @@
 from typing_extensions import Final
 
 from mypy.nodes import (
-    ARG_OPT, ARG_POS, MDEF, Argument, AssignmentStmt, CallExpr,
+    ARG_OPT, ARG_NAMED, ARG_NAMED_OPT, ARG_POS, MDEF, Argument, AssignmentStmt, CallExpr,
     Context, Expression, JsonDict, NameExpr, RefExpr,
     SymbolTableNode, TempNode, TypeInfo, Var, TypeVarExpr, PlaceholderNode
 )
@@ -49,11 +49,18 @@ def __init__(
         self.kw_only = kw_only
 
     def to_argument(self) -> Argument:
+        arg_kind = ARG_POS
+        if self.kw_only and self.has_default:
+            arg_kind = ARG_NAMED_OPT
+        elif self.kw_only and not self.has_default:
+            arg_kind = ARG_NAMED
+        elif not self.kw_only and self.has_default:
+            arg_kind = ARG_OPT
         return Argument(
             variable=self.to_var(),
             type_annotation=self.type,
             initializer=None,
-            kind=ARG_OPT if self.has_default else ARG_POS,
+            kind=arg_kind,
         )
 
     def to_var(self) -> Var:

test-data/unit/check-dataclasses.test

@@ -321,6 +321,13 @@ class Application:
     rating: int
 
 Application(rating=5)
+Application(name='name', rating=5)
+Application()  # E: Missing named argument "rating" for "Application"
+Application('name')  # E: Too many positional arguments for "Application" # E: Missing named argument "rating" for "Application"
+Application('name', 123)  # E: Too many positional arguments for "Application"
+Application('name', rating=123)  # E: Too many positional arguments for "Application"
+Application(name=123, rating='name') # E: Argument "name" to "Application" has incompatible type "int"; expected "str" # E: Argument "rating" to "Application" has incompatible type "str"; expected "int"
+Application(rating='name', name=123) # E: Argument "rating" to "Application" has incompatible type "str"; expected "int" # E: Argument "name" to "Application" has incompatible type "int"; expected "str" 
 
 [builtins fixtures/list.pyi]
 
@@ -334,6 +341,12 @@ class Application:
     rating: int = field(kw_only=True)
 
 Application(rating=5)
+Application('name', rating=123)
+Application(name='name', rating=5)
+Application()  # E: Missing named argument "rating" for "Application"
+Application('name')  # E: Missing named argument "rating" for "Application"
+Application('name', 123)  # E: Too many positional arguments for "Application"
+Application(123, rating='name') # E: Argument 1 to "Application" has incompatible type "int"; expected "str" # E: Argument "rating" to "Application" has incompatible type "str"; expected "int"
 
 [builtins fixtures/list.pyi]
 
@@ -346,6 +359,12 @@ class Application:
     name: str = 'Unnamed'
     rating: int = field(kw_only=False)  # E: Attributes without a default cannot follow attributes with one 
 
+Application(name='name', rating=5)
+Application('name', 123)
+Application('name', rating=123)
+Application()  # E: Missing positional argument "name" in call to "Application"
+Application('name')  # E: Too few arguments for "Application"
+
 [builtins fixtures/list.pyi]
 
 [case testDataclassesOrderingKwOnlyWithSentinel]
@@ -359,6 +378,11 @@ class Application:
     rating: int
 
 Application(rating=5)
+Application(name='name', rating=5)
+Application()  # E: Missing named argument "rating" for "Application"
+Application('name')  # E: Too many positional arguments for "Application" # E: Missing named argument "rating" for "Application"
+Application('name', 123)  # E: Too many positional arguments for "Application"
+Application('name', rating=123)  # E: Too many positional arguments for "Application"
 
 [builtins fixtures/list.pyi]
 
@@ -372,6 +396,12 @@ class Application:
     name: str = 'Unnamed'
     rating: int = field(kw_only=False)  # E: Attributes without a default cannot follow attributes with one 
 
+Application(name='name', rating=5)
+Application()  # E: Missing positional argument "name" in call to "Application"
+Application('name')  # E: Too many positional arguments for "Application" # E: Too few arguments for "Application"
+Application('name', 123)  # E: Too many positional arguments for "Application"
+Application('name', rating=123)  # E: Too many positional arguments for "Application"
+
 [builtins fixtures/list.pyi]
 
 [case testDataclassesOrderingKwOnlyWithSentinelAndSubclass]
@@ -391,6 +421,10 @@ class D(Base):
     a: str = "a"
 
 D("Hello", "World")
+D(x="Hello", z="World")
+D("Hello", "World", y=1, w=2, a="b")
+D("Hello")  # E: Missing positional argument "z" in call to "D"
+D()  # E: Missing positional arguments "x", "z" in call to "D"
 
 [case testDataclassesOrderingKwOnlyWithMultipleSentinel]
 # flags: --python-version 3.10