From d8d6812bdf2e5d12e3d57baab648df3e869950f0 Mon Sep 17 00:00:00 2001
From: Bruno Oliveira <nicoddemus@gmail.com>
Date: Thu, 15 Apr 2021 08:55:42 -0300
Subject: [PATCH] Merge pull request #8540 from hauntsaninja/assert310

(cherry picked from commit af31c60db1dc4e513f47aabf8f6e844b23afd35f)
---
 AUTHORS                          |  1 +
 changelog/8539.bugfix.rst        |  1 +
 src/_pytest/assertion/rewrite.py | 26 ++++++++++++++++++++------
 3 files changed, 22 insertions(+), 6 deletions(-)
 create mode 100644 changelog/8539.bugfix.rst

diff --git a/AUTHORS b/AUTHORS
index b35bebf7af3..2c690c5d28f 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -273,6 +273,7 @@ Sankt Petersbug
 Segev Finer
 Serhii Mozghovyi
 Seth Junot
+Shantanu Jain
 Shubham Adep
 Simon Gomizelj
 Simon Kerr
diff --git a/changelog/8539.bugfix.rst b/changelog/8539.bugfix.rst
new file mode 100644
index 00000000000..a2098610e29
--- /dev/null
+++ b/changelog/8539.bugfix.rst
@@ -0,0 +1 @@
+Fixed assertion rewriting on Python 3.10.
diff --git a/src/_pytest/assertion/rewrite.py b/src/_pytest/assertion/rewrite.py
index 805d4c8b35b..37ff076aab5 100644
--- a/src/_pytest/assertion/rewrite.py
+++ b/src/_pytest/assertion/rewrite.py
@@ -673,12 +673,9 @@ def run(self, mod: ast.Module) -> None:
         if not mod.body:
             # Nothing to do.
             return
-        # Insert some special imports at the top of the module but after any
-        # docstrings and __future__ imports.
-        aliases = [
-            ast.alias("builtins", "@py_builtins"),
-            ast.alias("_pytest.assertion.rewrite", "@pytest_ar"),
-        ]
+
+        # We'll insert some special imports at the top of the module, but after any
+        # docstrings and __future__ imports, so first figure out where that is.
         doc = getattr(mod, "docstring", None)
         expect_docstring = doc is None
         if doc is not None and self.is_rewrite_disabled(doc):
@@ -710,10 +707,27 @@ def run(self, mod: ast.Module) -> None:
             lineno = item.decorator_list[0].lineno
         else:
             lineno = item.lineno
+        # Now actually insert the special imports.
+        if sys.version_info >= (3, 10):
+            aliases = [
+                ast.alias("builtins", "@py_builtins", lineno=lineno, col_offset=0),
+                ast.alias(
+                    "_pytest.assertion.rewrite",
+                    "@pytest_ar",
+                    lineno=lineno,
+                    col_offset=0,
+                ),
+            ]
+        else:
+            aliases = [
+                ast.alias("builtins", "@py_builtins"),
+                ast.alias("_pytest.assertion.rewrite", "@pytest_ar"),
+            ]
         imports = [
             ast.Import([alias], lineno=lineno, col_offset=0) for alias in aliases
         ]
         mod.body[pos:pos] = imports
+
         # Collect asserts.
         nodes: List[ast.AST] = [mod]
         while nodes: