Fix incorrect preferred-modules matches (#8481)

Co-authored-by: d33bs <dave.bunten@cuanschutz.edu>
(cherry picked from commit d64c0cc1484b0cbea5fd3a9dfac4c0d6ddc7d1aa)

Co-authored-by: Daniël van Noord <13665637+DanielNoord@users.noreply.github.com>

3 files changed, 29 insertions, 1 deletions

diff --git a/doc/whatsnew/fragments/8453.bugfix b/doc/whatsnew/fragments/8453.bugfix
new file mode 100644
index 000000000..6bec2b0b9
--- /dev/null
+++ b/doc/whatsnew/fragments/8453.bugfix
@@ -0,0 +1,3 @@
+Fix a regression of ``preferred-modules`` where a partial match was used instead of the required full match.
+
+Closes #8453
diff --git a/pylint/checkers/imports.py b/pylint/checkers/imports.py
index dee12e591..1ed70d958 100644
--- a/pylint/checkers/imports.py
+++ b/pylint/checkers/imports.py
@@ -922,7 +922,15 @@ class ImportsChecker(DeprecatedMixin, BaseChecker):
             mod_compare = [f"{node.modname}.{name[0]}" for name in node.names]
 
         # find whether there are matches with the import vs preferred_modules keys
-        matches = [k for k in self.preferred_modules for mod in mod_compare if k in mod]
+        matches = [
+            k
+            for k in self.preferred_modules
+            for mod in mod_compare
+            # exact match
+            if k == mod
+            # checks for base module matches
+            or k in mod.split(".")[0]
+        ]
 
         # if we have matches, add message
         if matches:
diff --git a/tests/checkers/unittest_imports.py b/tests/checkers/unittest_imports.py
index 7544e3422..d454c8161 100644
--- a/tests/checkers/unittest_imports.py
+++ b/tests/checkers/unittest_imports.py
@@ -192,6 +192,23 @@ class TestImportsChecker(CheckerTestCase):
         # assert there were no errors
         assert len(errors) == 0
 
+        # Test for challenges with preferred modules indefinite matches
+        Run(
+            [
+                f"{os.path.join(REGR_DATA, 'preferred_module/unpreferred_submodule.py')}",
+                "-d all",
+                "-e preferred-module",
+                # prefer pathlib instead of random (testing to avoid regression)
+                # pathlib shouldn't match with path, which is in the test file
+                "--preferred-modules=random:pathlib",
+            ],
+            exit=False,
+        )
+        _, errors = capsys.readouterr()
+
+        # Assert there were no errors
+        assert len(errors) == 0
+
     @staticmethod
     def test_allow_reexport_package(capsys: CaptureFixture[str]) -> None:
         """Test --allow-reexport-from-package option."""