From cf01e9f3693c8cdcb26b9e4e7ff74429b13c5d44 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20Robert?= <cr52@protonmail.com>
Date: Sat, 11 Sep 2021 16:22:02 +0200
Subject: [PATCH] EHH: simplify logic in versioned_branches.py

---
 pyupgrade/_plugins/versioned_branches.py | 84 ++++++------------------
 1 file changed, 21 insertions(+), 63 deletions(-)

diff --git a/pyupgrade/_plugins/versioned_branches.py b/pyupgrade/_plugins/versioned_branches.py
index 030e1a4e..4604fa7d 100644
--- a/pyupgrade/_plugins/versioned_branches.py
+++ b/pyupgrade/_plugins/versioned_branches.py
@@ -106,13 +106,16 @@ def visit_If(
         node: ast.If,
         parent: ast.AST,
 ) -> Iterable[Tuple[Offset, TokenFunc]]:
-    if state.settings.min_version >= (3,) and (
-        len(state.settings.min_version) >= 2
-    ):
-        py3_minor = state.settings.min_version[1]
+
+    min_version: Tuple[int, ...]
+    if state.settings.min_version == (3,):
+        min_version = (3, 0)
+    else:
+        min_version = state.settings.min_version
+    assert len(min_version) >= 2
 
     if (
-            state.settings.min_version >= (3,) and (
+            min_version >= (3,) and (
                 # if six.PY2:
                 is_name_attr(node.test, state.from_imports, 'six', ('PY2',)) or
                 # if not six.PY3:
@@ -127,6 +130,7 @@ def visit_If(
                     )
                 ) or
                 # sys.version_info == 2 or < (3,)
+                # or < (3, n) or <= (3, n) (with n<m)
                 (
                     isinstance(node.test, ast.Compare) and
                     is_name_attr(
@@ -137,33 +141,10 @@ def visit_If(
                     ) and
                     len(node.test.ops) == 1 and (
                         _eq(node.test, 2) or
-                        _compare_to_3(node.test, ast.Lt)
-                    )
-                ) or
-                # sys.version_info < (3, n) (with n<=m)
-                # or sys.version_info <= (3, n) (with n<m)
-                (
-                    len(state.settings.min_version) >= 2 and (
-                        isinstance(node.test, ast.Compare) and
-                        is_name_attr(
-                            node.test.left,
-                            state.from_imports,
-                            'sys',
-                            ('version_info',),
-                        ) and
-                        len(node.test.ops) == 1 and (
-                            _compare_to_3(
-                                node.test,
-                                ast.Lt,
-                                minor=py3_minor,
-                            ) or any(
-                                _compare_to_3(
-                                    node.test,
-                                    (ast.Lt, ast.LtE),
-                                    minor=minor,
-                                )
-                                for minor in range(py3_minor)
-                            )
+                        _compare_to_3(node.test, ast.Lt, min_version[1]) or
+                        any(
+                            _compare_to_3(node.test, (ast.Lt, ast.LtE), minor)
+                            for minor in range(min_version[1])
                         )
                     )
                 )
@@ -172,7 +153,7 @@ def visit_If(
         if node.orelse and not isinstance(node.orelse[0], ast.If):
             yield ast_to_offset(node), _fix_py2_block
     elif (
-            state.settings.min_version >= (3,) and (
+            min_version >= (3,) and (
                 # if six.PY3:
                 is_name_attr(node.test, state.from_imports, 'six', ('PY3',)) or
                 # if not six.PY2:
@@ -187,6 +168,8 @@ def visit_If(
                     )
                 ) or
                 # sys.version_info == 3 or >= (3,) or > (3,)
+                # sys.version_info >= (3, n) (with n<=m)
+                # or sys.version_info > (3, n) (with n<m)
                 (
                     isinstance(node.test, ast.Compare) and
                     is_name_attr(
@@ -197,37 +180,12 @@ def visit_If(
                     ) and
                     len(node.test.ops) == 1 and (
                         _eq(node.test, 3) or
-                        _compare_to_3(node.test, (ast.Gt, ast.GtE))
-                    )
-                ) or
-                # sys.version_info >= (3, n) (with n<=m)
-                # or sys.version_info > (3, n) (with n<m)
-                (
-                    len(state.settings.min_version) >= 2 and (
-
-                        isinstance(node.test, ast.Compare) and
-                        is_name_attr(
-                            node.test.left,
-                            state.from_imports,
-                            'sys',
-                            ('version_info',),
-                        ) and
-                        len(node.test.ops) == 1 and
-                        (
-                            _compare_to_3(
-                                node.test,
-                                ast.GtE,
-                                minor=py3_minor,
-                            ) or any(
-                                _compare_to_3(
-                                    node.test,
-                                    (ast.Gt, ast.GtE),
-                                    minor=minor,
-                                )
-                                for minor in range(py3_minor)
-                            )
+                        _compare_to_3(node.test, (ast.Gt, ast.GtE)) or
+                        _compare_to_3(node.test, ast.GtE, min_version[1]) or
+                        any(
+                            _compare_to_3(node.test, (ast.Gt, ast.GtE), minor)
+                            for minor in range(min_version[1])
                         )
-
                     )
                 )
             )