Support init=False for dataclass_transform

test/test_inference/test_signature.py

@@ -426,16 +426,19 @@ def test_dataclass_signature(
 
 
 dataclass_transform_cases = [
-    # Direct
-    ['@dataclass_transform\nclass X:', []],
-    # With params
-    ['@dataclass_transform(eq=True)\nclass X:', []],
+    # Attributes on the decorated class and its base classes
+    # are not considered to be fields.
+    # 1/ Declare dataclass transformer
+    # Base Class
+    ['@dataclass_transform\nclass X:', [], False],
+    # Base Class with params
+    ['@dataclass_transform(eq=True)\nclass X:', [], False],
     # Subclass
     [dedent('''
         class Y():
             y: int
         @dataclass_transform
-        class X(Y):'''), []],
+        class X(Y):'''), [], False],
     # Both classes
     [dedent('''
         @dataclass_transform
@@ -443,22 +446,23 @@ dataclass_transform_cases = [
             y: int
             z = 5
         @dataclass_transform
-        class X(Y):'''), ['y']],
-    # Base class
+        class X(Y):'''), [], False],
+    # 2/ Declare dataclass transformed
+    # Class based
     [dedent('''
         @dataclass_transform
         class Y():
             y: int
             z = 5
-        class X(Y):'''), []],
-    # Alternative decorator
+        class X(Y):'''), [], True],
+    # Decorator based
     [dedent('''
         @dataclass_transform
         def create_model(cls):
             return cls
         @create_model
-        class X:'''), []],
-    # Metaclass
+        class X:'''), [], True],
+    # Metaclass based
     [dedent('''
         @dataclass_transform
         class ModelMeta():
@@ -467,38 +471,86 @@ dataclass_transform_cases = [
         class ModelBase(metaclass=ModelMeta):
             t: int
             p = 5
-        class X(ModelBase):'''), []],
+        class X(ModelBase):'''), [], True],
+    # 3/ Init tweaks
+    # init=False
+    [dedent('''
+        @dataclass_transform(init=False)
+        class Y():
+            y: int
+            z = 5
+        class X(Y):'''), [], False],
+    [dedent('''
+        @dataclass_transform(eq=True, init=False)
+        class Y():
+            y: int
+            z = 5
+        class X(Y):'''), [], False],
+    # custom init
+    [dedent('''
+    @dataclass_transform()
+    class Y():
+        y: int
+        z = 5
+    class X(Y):
+        def __init__(self, toto: str):
+            pass
+        '''), ["toto"], False],
 ]
 
-ids = ["direct", "with_params", "sub", "both", "base", "alternative_decorator", "metaclass"]
+ids = [
+    "direct_transformer",
+    "transformer_with_params",
+    "subclass_transformer",
+    "both_transformer",
+    "base_transformed",
+    "decorator_transformed",
+    "metaclass_transformed",
+    "init_false",
+    "init_false_multiple",
+    "custom_init",
+]
 
 
 @pytest.mark.parametrize(
-    'start, start_params', dataclass_transform_cases, ids=ids
+    'start, start_params, include_params', dataclass_transform_cases, ids=ids
 )
-def test_extensions_dataclass_transform_signature(Script, skip_pre_python37, start, start_params):
-    code = dedent('''
+def test_extensions_dataclass_transform_signature(
+    Script, skip_pre_python37, start, start_params, include_params
+):
+    code = dedent(
+        """
             name: str
             foo = 3
             price: float
             quantity: int = 0.0
 
-        X(''')
+        X("""
+    )
 
-    code = 'from typing_extensions import dataclass_transform\n' + start + code
+    code = "from typing_extensions import dataclass_transform\n" + start + code
 
-    sig, = Script(code).get_signatures()
-    assert [p.name for p in sig.params] == start_params + ['name', 'price', 'quantity']
-    quantity, = sig.params[-1].infer()
-    assert quantity.name == 'int'
-    price, = sig.params[-2].infer()
-    assert price.name == 'float'
+    (sig,) = Script(code).get_signatures()
+    expected_params = (
+        [*start_params, "name", "price", "quantity"]
+        if include_params
+        else [*start_params]
+    )
+    assert [p.name for p in sig.params] == expected_params
+
+    if include_params:
+        quantity, = sig.params[-1].infer()
+        assert quantity.name == 'int'
+        price, = sig.params[-2].infer()
+        assert price.name == 'float'
 
 
 @pytest.mark.parametrize(
-    'start, start_params', dataclass_transform_cases, ids=ids
+    "start, start_params, include_params", dataclass_transform_cases, ids=ids
 )
-def test_dataclass_transform_signature(Script, skip_pre_python311, start, start_params):
+def test_dataclass_transform_signature(
+    Script, skip_pre_python311, start, start_params, include_params
+):
     code = dedent('''
             name: str
             foo = 3
@@ -510,11 +562,18 @@ def test_dataclass_transform_signature(Script, skip_pre_python311, start, start_
     code = 'from typing import dataclass_transform\n' + start + code
 
     sig, = Script(code).get_signatures()
-    assert [p.name for p in sig.params] == start_params + ['name', 'price', 'quantity']
-    quantity, = sig.params[-1].infer()
-    assert quantity.name == 'int'
-    price, = sig.params[-2].infer()
-    assert price.name == 'float'
+    expected_params = (
+        [*start_params, "name", "price", "quantity"]
+        if include_params
+        else [*start_params]
+    )
+    assert [p.name for p in sig.params] == expected_params
+
+    if include_params:
+        quantity, = sig.params[-1].infer()
+        assert quantity.name == 'int'
+        price, = sig.params[-2].infer()
+        assert price.name == 'float'
 
 
 @pytest.mark.parametrize(