From 099d6339261bc6cc5c2989fbf6a47847196926f3 Mon Sep 17 00:00:00 2001
From: Marc Mueller <30130371+cdce8p@users.noreply.github.com>
Date: Sun, 13 Feb 2022 00:54:22 +0100
Subject: [PATCH 1/4] Fix ClassDef.fromlineno with Python 3.7

---
 ChangeLog                                  |  3 ++
 astroid/const.py                           |  1 +
 astroid/nodes/scoped_nodes/scoped_nodes.py | 20 ++++++++-
 tests/unittest_builder.py                  | 48 +++++++++++++++++++++-
 4 files changed, 69 insertions(+), 3 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 6baadce493..b281e39e0b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -42,6 +42,9 @@ Release date: TBA
 
   Closes #1085
 
+* Fix ``ClassDef.fromlineno``. Only in Python 3.7 the ``lineno`` attribute includes decorators.
+  ``fromlineno`` should return the line of the ``class`` statement itself.
+
 What's New in astroid 2.9.4?
 ============================
 Release date: TBA
diff --git a/astroid/const.py b/astroid/const.py
index 81384e346d..6a2d46af90 100644
--- a/astroid/const.py
+++ b/astroid/const.py
@@ -1,6 +1,7 @@
 import enum
 import sys
 
+PY37 = sys.version_info[:2] == (3, 7)
 PY38 = sys.version_info[:2] == (3, 8)
 PY37_PLUS = sys.version_info >= (3, 7)
 PY38_PLUS = sys.version_info >= (3, 8)
diff --git a/astroid/nodes/scoped_nodes/scoped_nodes.py b/astroid/nodes/scoped_nodes/scoped_nodes.py
index f8da9d2602..6919c79f5b 100644
--- a/astroid/nodes/scoped_nodes/scoped_nodes.py
+++ b/astroid/nodes/scoped_nodes/scoped_nodes.py
@@ -55,7 +55,7 @@
 from astroid import bases
 from astroid import decorators as decorators_mod
 from astroid import mixins, util
-from astroid.const import PY39_PLUS
+from astroid.const import PY37, PY39_PLUS
 from astroid.context import (
     CallContext,
     InferenceContext,
@@ -2297,6 +2297,24 @@ def _newstyle_impl(self, context=None):
         doc=("Whether this is a new style class or not\n\n" ":type: bool or None"),
     )
 
+    @decorators_mod.cachedproperty
+    def fromlineno(self):
+        """The first line that this node appears on in the source code.
+
+        :type: int or None
+        """
+        if PY37:
+            # Only in Python 3.7 is the lineno the line number of the first decorator.
+            # We want the class statement lineno. Similar to 'FunctionDef.fromlineno'
+            lineno = self.lineno
+            if self.decorators is not None:
+                lineno += sum(
+                    node.tolineno - node.lineno + 1 for node in self.decorators.nodes
+                )
+
+            return lineno
+        return super().fromlineno
+
     @decorators_mod.cachedproperty
     def blockstart_tolineno(self):
         """The line on which the beginning of this block ends.
diff --git a/tests/unittest_builder.py b/tests/unittest_builder.py
index eb7fbdc77f..586276c7b1 100644
--- a/tests/unittest_builder.py
+++ b/tests/unittest_builder.py
@@ -29,12 +29,13 @@
 import os
 import socket
 import sys
+import textwrap
 import unittest
 
 import pytest
 
 from astroid import Instance, builder, nodes, test_utils, util
-from astroid.const import PY38_PLUS
+from astroid.const import PY37, PY38_PLUS
 from astroid.exceptions import (
     AstroidBuildingError,
     AstroidSyntaxError,
@@ -132,12 +133,55 @@ def function(
             __name__,
         )
         function = astroid["function"]
-        # XXX discussable, but that's what is expected by pylint right now
+        # XXX discussable, but that's what is expected by pylint right now, similar to ClassDef
         self.assertEqual(function.fromlineno, 3)
         self.assertEqual(function.tolineno, 5)
         self.assertEqual(function.decorators.fromlineno, 2)
         self.assertEqual(function.decorators.tolineno, 2)
 
+    @staticmethod
+    def test_decorated_class_lineno() -> None:
+        code = textwrap.dedent(
+            """
+        class A:
+            ...
+
+        @decorator
+        class B:
+            ...
+
+        @deco1
+        @deco2(
+            var=42
+        )
+        class C:
+            ...
+        """
+        )
+
+        ast_module: nodes.Module = builder.parse(code)  # type: ignore[assignment]
+
+        # XXX discussable, but that's what is expected by pylint right now, similar to FunctionDef
+        a = ast_module.body[0]
+        assert isinstance(a, nodes.ClassDef)
+        assert a.fromlineno == 2
+        assert a.tolineno == 3
+
+        b = ast_module.body[1]
+        assert isinstance(b, nodes.ClassDef)
+        assert b.fromlineno == 6
+        assert b.tolineno == 7
+
+        c = ast_module.body[2]
+        assert isinstance(c, nodes.ClassDef)
+        if PY37:
+            # Not perfect, but best we can do for Python 3.7
+            # Can't detect closing bracket on new line.
+            assert c.fromlineno == 12
+        else:
+            assert c.fromlineno == 13
+        assert c.tolineno == 14
+
     def test_class_lineno(self) -> None:
         stmts = self.astroid.body
         # on line 20:

From 949fda154db277022d6114824effe00410a9adaa Mon Sep 17 00:00:00 2001
From: Marc Mueller <30130371+cdce8p@users.noreply.github.com>
Date: Sun, 13 Feb 2022 01:43:44 +0100
Subject: [PATCH 2/4] Fix Python 3.6

---
 ChangeLog                                  | 2 +-
 astroid/const.py                           | 1 -
 astroid/nodes/scoped_nodes/scoped_nodes.py | 6 +++---
 tests/unittest_builder.py                  | 4 ++--
 4 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index b281e39e0b..9aeebd438c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -42,7 +42,7 @@ Release date: TBA
 
   Closes #1085
 
-* Fix ``ClassDef.fromlineno``. Only in Python 3.7 the ``lineno`` attribute includes decorators.
+* Fix ``ClassDef.fromlineno``. For Python < 3.8 the ``lineno`` attribute includes decorators.
   ``fromlineno`` should return the line of the ``class`` statement itself.
 
 What's New in astroid 2.9.4?
diff --git a/astroid/const.py b/astroid/const.py
index 6a2d46af90..81384e346d 100644
--- a/astroid/const.py
+++ b/astroid/const.py
@@ -1,7 +1,6 @@
 import enum
 import sys
 
-PY37 = sys.version_info[:2] == (3, 7)
 PY38 = sys.version_info[:2] == (3, 8)
 PY37_PLUS = sys.version_info >= (3, 7)
 PY38_PLUS = sys.version_info >= (3, 8)
diff --git a/astroid/nodes/scoped_nodes/scoped_nodes.py b/astroid/nodes/scoped_nodes/scoped_nodes.py
index 6919c79f5b..67356a25de 100644
--- a/astroid/nodes/scoped_nodes/scoped_nodes.py
+++ b/astroid/nodes/scoped_nodes/scoped_nodes.py
@@ -55,7 +55,7 @@
 from astroid import bases
 from astroid import decorators as decorators_mod
 from astroid import mixins, util
-from astroid.const import PY37, PY39_PLUS
+from astroid.const import PY38_PLUS, PY39_PLUS
 from astroid.context import (
     CallContext,
     InferenceContext,
@@ -2303,8 +2303,8 @@ def fromlineno(self):
 
         :type: int or None
         """
-        if PY37:
-            # Only in Python 3.7 is the lineno the line number of the first decorator.
+        if not PY38_PLUS:
+            # For Python < 3.8 the lineno is the line number of the first decorator.
             # We want the class statement lineno. Similar to 'FunctionDef.fromlineno'
             lineno = self.lineno
             if self.decorators is not None:
diff --git a/tests/unittest_builder.py b/tests/unittest_builder.py
index 586276c7b1..3c1b7138ac 100644
--- a/tests/unittest_builder.py
+++ b/tests/unittest_builder.py
@@ -35,7 +35,7 @@
 import pytest
 
 from astroid import Instance, builder, nodes, test_utils, util
-from astroid.const import PY37, PY38_PLUS
+from astroid.const import PY38_PLUS
 from astroid.exceptions import (
     AstroidBuildingError,
     AstroidSyntaxError,
@@ -174,7 +174,7 @@ class C:
 
         c = ast_module.body[2]
         assert isinstance(c, nodes.ClassDef)
-        if PY37:
+        if not PY38_PLUS:
             # Not perfect, but best we can do for Python 3.7
             # Can't detect closing bracket on new line.
             assert c.fromlineno == 12

From ef60922b0bf8502c937de0fdec417036515b80ea Mon Sep 17 00:00:00 2001
From: Marc Mueller <30130371+cdce8p@users.noreply.github.com>
Date: Sun, 13 Feb 2022 13:04:00 +0100
Subject: [PATCH 3/4] Code review

---
 astroid/nodes/scoped_nodes/scoped_nodes.py | 16 +++++-----------
 tests/unittest_builder.py                  |  1 -
 2 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/astroid/nodes/scoped_nodes/scoped_nodes.py b/astroid/nodes/scoped_nodes/scoped_nodes.py
index 67356a25de..35d74c6acd 100644
--- a/astroid/nodes/scoped_nodes/scoped_nodes.py
+++ b/astroid/nodes/scoped_nodes/scoped_nodes.py
@@ -1706,13 +1706,10 @@ def type(
         return type_name
 
     @decorators_mod.cachedproperty
-    def fromlineno(self):
-        """The first line that this node appears on in the source code.
-
-        :type: int or None
-        """
+    def fromlineno(self) -> Optional[int]:
+        """The first line that this node appears on in the source code."""
         # lineno is the line number of the first decorator, we want the def
-        # statement lineno
+        # statement lineno. Similar to 'ClassDef.fromlineno'
         lineno = self.lineno
         if self.decorators is not None:
             lineno += sum(
@@ -2298,11 +2295,8 @@ def _newstyle_impl(self, context=None):
     )
 
     @decorators_mod.cachedproperty
-    def fromlineno(self):
-        """The first line that this node appears on in the source code.
-
-        :type: int or None
-        """
+    def fromlineno(self) -> Optional[int]:
+        """The first line that this node appears on in the source code."""
         if not PY38_PLUS:
             # For Python < 3.8 the lineno is the line number of the first decorator.
             # We want the class statement lineno. Similar to 'FunctionDef.fromlineno'
diff --git a/tests/unittest_builder.py b/tests/unittest_builder.py
index 3c1b7138ac..17d139b374 100644
--- a/tests/unittest_builder.py
+++ b/tests/unittest_builder.py
@@ -161,7 +161,6 @@ class C:
 
         ast_module: nodes.Module = builder.parse(code)  # type: ignore[assignment]
 
-        # XXX discussable, but that's what is expected by pylint right now, similar to FunctionDef
         a = ast_module.body[0]
         assert isinstance(a, nodes.ClassDef)
         assert a.fromlineno == 2

From 822ccb706c25900663e349885010c7b3a0f9b143 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Sat, 19 Feb 2022 09:17:21 +0000
Subject: [PATCH 4/4] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 tests/unittest_builder.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/unittest_builder.py b/tests/unittest_builder.py
index 0ec26c927d..151abcbe02 100644
--- a/tests/unittest_builder.py
+++ b/tests/unittest_builder.py
@@ -32,8 +32,8 @@
 import py_compile
 import socket
 import sys
-import textwrap
 import tempfile
+import textwrap
 import unittest
 
 import pytest