From 18cd922aabb4a3c318d3d57749b940a13ae4a50c Mon Sep 17 00:00:00 2001
From: Harmen Stoppels <me@harmenstoppels.nl>
Date: Tue, 11 Feb 2025 19:30:50 +0100
Subject: [PATCH] style.py: fix false negative in redundant import statements
 (#48980)

---
 lib/spack/spack/cmd/style.py      | 7 ++++---
 lib/spack/spack/test/cmd/style.py | 4 ++++
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/lib/spack/spack/cmd/style.py b/lib/spack/spack/cmd/style.py
index 82df6ad0f80..887698ddd75 100644
--- a/lib/spack/spack/cmd/style.py
+++ b/lib/spack/spack/cmd/style.py
@@ -6,7 +6,7 @@
 import os
 import re
 import sys
-from itertools import zip_longest
+from itertools import islice, zip_longest
 from typing import Dict, List, Optional
 
 import llnl.util.tty as tty
@@ -423,7 +423,8 @@ def _run_import_check(
             continue
 
         for m in is_abs_import.finditer(contents):
-            if contents.count(m.group(1)) == 1:
+            # Find at most two occurences: the first is the import itself, the second is its usage.
+            if len(list(islice(re.finditer(rf"{re.escape(m.group(1))}(?!\w)", contents), 2))) == 1:
                 to_remove.append(m.group(0))
                 exit_code = 1
                 print(f"{pretty_path}: redundant import: {m.group(1)}", file=out)
@@ -438,7 +439,7 @@ def _run_import_check(
             module = _module_part(root, m.group(0))
             if not module or module in to_add:
                 continue
-            if re.search(rf"import {re.escape(module)}\b(?!\.)", contents):
+            if re.search(rf"import {re.escape(module)}(?!\w|\.)", contents):
                 continue
             to_add.add(module)
             exit_code = 1
diff --git a/lib/spack/spack/test/cmd/style.py b/lib/spack/spack/test/cmd/style.py
index 6cbd97456d8..9a21deff678 100644
--- a/lib/spack/spack/test/cmd/style.py
+++ b/lib/spack/spack/test/cmd/style.py
@@ -304,6 +304,8 @@ def test_run_import_check(tmp_path: pathlib.Path):
     contents = '''
 import spack.cmd
 import spack.config  # do not drop this import because of this comment
+import spack.repo
+import spack.repo_utils
 
 # this comment about spack.error should not be removed
 class Example(spack.build_systems.autotools.AutotoolsPackage):
@@ -314,6 +316,7 @@ def foo(config: "spack.error.SpackError"):
     # the type hint is quoted, so it should not be removed
     spack.util.executable.Executable("example")
     print(spack.__version__)
+    print(spack.repo_utils.__file__)
 '''
     file.write_text(contents)
     root = str(tmp_path)
@@ -329,6 +332,7 @@ def foo(config: "spack.error.SpackError"):
     output = output_buf.getvalue()
 
     assert "issues.py: redundant import: spack.cmd" in output
+    assert "issues.py: redundant import: spack.repo" in output
     assert "issues.py: redundant import: spack.config" not in output  # comment prevents removal
     assert "issues.py: missing import: spack" in output  # used by spack.__version__
     assert "issues.py: missing import: spack.build_systems.autotools" in output