From a5569a07ea2c09bdb73e1262007c8d501fccd8ec Mon Sep 17 00:00:00 2001
From: Josh66 <info@aska-systems.de>
Date: Mon, 28 Sep 2026 13:27:12 +0000
Subject: [PATCH] fix(resolution): explicit-alias check matches the exact
 module, outside strings

Review follow-up: `import other.pkg.settings as settings` or a string
`"import pkg.settings as settings"` no longer marks a plain
`import pkg.settings` as explicitly aliased, which attached a write to the
wrong module.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018CQubRS1bXvaoApgPyLf66
---
 __tests__/function-ref.test.ts | 10 ++++++++++
 src/resolution/name-matcher.ts |  5 +++--
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/__tests__/function-ref.test.ts b/__tests__/function-ref.test.ts
index 9138efd0..0be8f8d6 100644
--- a/__tests__/function-ref.test.ts
+++ b/__tests__/function-ref.test.ts
@@ -1439,6 +1439,16 @@ def init():
       namespace_import_binds_root: [{ 'pkg/__init__.py': '', 'pkg/settings.py': header,
         'c.py': 'import pkg.settings\nfrom decoy import Decoy\n\nsettings = Bag()\nsettings.conn = Decoy()\n',
         'd.py': 'from pkg import settings\n\ndef cb(pool):\n    pool.submit(settings.conn.fetch)\n' }, ['cb -> Store::fetch']],
+      // `other.pkg.settings as settings` is not an explicit alias of `pkg.settings`: the
+      // write goes to the other module, so pkg's global keeps its type (the consumer's
+      // relative import names pkg/settings.py exactly).
+      alias_of_longer_module_is_not_explicit: [{ 'pkg/__init__.py': '', 'pkg/settings.py': header,
+        'other/__init__.py': '', 'other/pkg/__init__.py': '', 'other/pkg/settings.py': 'conn = None\n',
+        'reset.py': 'import pkg.settings\nimport other.pkg.settings as settings\nfrom decoy import Decoy\n\ndef reset():\n    settings.conn = Decoy()\n',
+        'pkg/d.py': 'from . import settings\n\ndef cb(pool):\n    pool.submit(settings.conn.fetch)\n' }, ['cb -> Store::fetch']],
+      alias_in_string_is_not_explicit: [{ 'pkg/__init__.py': '', 'pkg/settings.py': 'conn = None\n',
+        'reset.py': 'import pkg.settings\nfrom decoy import Decoy\nnote = "import pkg.settings as settings"\n\ndef reset():\n    settings.conn = Decoy()\n',
+        'd.py': 'from pkg import settings\n\ndef cb(pool):\n    pool.submit(settings.conn.fetch)\n' }, []],
       explicit_alias_equal_to_leaf: [{ 'pkg/__init__.py': '', 'pkg/settings.py': header,
         'reset.py': 'import pkg.settings as settings\nfrom decoy import Decoy\n\ndef reset():\n    settings.conn = Decoy()\n',
         'd.py': 'from pkg import settings\n\ndef cb(pool):\n    pool.submit(settings.conn.fetch)\n' }, []],
diff --git a/src/resolution/name-matcher.ts b/src/resolution/name-matcher.ts
index fae96780..3ae55181 100644
--- a/src/resolution/name-matcher.ts
+++ b/src/resolution/name-matcher.ts
@@ -685,9 +685,10 @@ function pythonModuleAliases(filePath: string, moduleFile: string, context: Reso
     const files = pythonModuleFiles(dotted, filePath, context);
     if (!files.includes(moduleFile)) continue;
     // The mapping cannot tell `import a.b` from `import a.b as b`; the source line can.
-    const explicit = new RegExp(`\\bimport\\s[^\\n]*\\b${m.source.replace(/\./g, '\\.')}\\s+as\\s+${m.localName}\\b`);
+    // Exactly this module (not `other.a.b`), outside string literals.
+    const explicit = new RegExp(`\\bimport\\s[^\\n]*(?<![\\w.])${m.source.replace(/\./g, '\\.')}\\s+as\\s+${m.localName}\\b`);
     const plainDotted = m.isNamespace && m.source.includes('.') && m.localName === m.source.split('.').pop() &&
-      !pythonMemberLines(filePath, context).some(line => explicit.test(line));
+      !pythonMemberLines(filePath, context).some(line => explicit.test(blankPythonStrings(line)));
     (files.length === 1 ? aliases : ambiguous).add(plainDotted ? m.source : m.localName);
   }
   return { aliases: [...aliases], ambiguous: [...ambiguous] };