Merge pull request #8 from atollk/i2023

I2023

README.md

@@ -92,6 +92,20 @@ import os
 The `import` syntax should not be used.
 
 
+### I2023
+When using the `import` syntax, do not duplicate module names in the `as`
+segment.
+
+```python
+# Bad
+import os.path as path
+
+# Good
+from os import path
+import os.path as ospath
+```
+
+
 ## `from` Syntax Errors
 
 ### I2040

flake8_import_restrictions/checker.py

@@ -20,6 +20,7 @@
     2020,
     2021,
     2022,
+    2023,
     2040,
     2041,
     2042,
@@ -32,6 +33,7 @@
     2001: ["*"],
     2002: ["*"],
     2021: ["*"],
+    2023: ["*"],
     2041: ["*"],
     2043: ["*"],
 }
@@ -106,6 +108,8 @@ def run(self) -> Iterable[Tuple[int, int, str, type]]:
                     yield from _i2021(node)
                 if _applies_to(node, ImportChecker.targetted_modules[2022]):
                     yield from _i2022(node)
+                if _applies_to(node, ImportChecker.targetted_modules[2023]):
+                    yield from _i2023(node)
 
             if isinstance(node, ast.ImportFrom):
                 if _applies_to(node, ImportChecker.targetted_modules[2001]):
@@ -133,6 +137,7 @@ def run(self) -> Iterable[Tuple[int, int, str, type]]:
     2020: "Missing import alias for non-trivial import.",
     2021: "Multiple imports in one import statement.",
     2022: "import statements are forbidden.",
+    2023: "import statements with alias must not contain duplicate module names.",
     2040: "Multiple imports in one from-import statement.",
     2041: "from-import statements must only import modules.",
     2042: "from-import statements must not import modules.",
@@ -141,12 +146,28 @@ def run(self) -> Iterable[Tuple[int, int, str, type]]:
     2045: "from-import statements are forbidden.",
 }
 
+ERROR_HINTS = {
+    2000: "Move this import to the top of the file.",
+    2001: 'Choose a longer alias after the "as" keyword.',
+    2002: 'Remove the "as" keyword and following alias.',
+    2020: 'Use "as" keyword and provide a shorter alias.',
+    2021: "Split onto multiple lines.",
+    2022: 'Use "from" syntax instead.',
+    2023: 'Use "from" syntax instead or choose a different alias.',
+    2040: "Split onto multiple lines.",
+    2041: "Import the containing module instead.",
+    2042: "Import functions/classes directly instead.",
+    2043: "Import individual elements instead.",
+    2044: "Change the imported module to an absolute path.",
+    2045: 'Use the "import" syntax instead.',
+}
+
 
 def _error_tuple(error_code: int, node: ast.AST) -> Tuple[int, int, str, type]:
     return (
         node.lineno,
         node.col_offset,
-        f"I{error_code} {ERROR_MESSAGES[error_code]}",
+        f"I{error_code} {ERROR_MESSAGES[error_code]} (hint: {ERROR_HINTS[error_code]})",
         ImportChecker,
     )
 
@@ -213,8 +234,7 @@ def _i2002(
 
 def _i2020(node: ast.Import) -> Iterable[Tuple[int, int, str, type]]:
     """
-    When using the import syntax, if the imported module is a submodule, i.e. not a top level module, an "as" segment
-    should be present.
+    When using the import syntax, if the imported module is a submodule, i.e. not a top level module, an "as" segment should be present.
     """
     for name in node.names:
         if "." in name.name and not name.asname:
@@ -237,6 +257,15 @@ def _i2022(node: ast.Import) -> Iterable[Tuple[int, int, str, type]]:
     yield _error_tuple(2022, node)
 
 
+def _i2023(node: ast.Import) -> Iterable[Tuple[int, int, str, type]]:
+    """
+    When using the `import` syntax, do not duplicate module names in the `as` segment.
+    """
+    for name in node.names:
+        if name.name.split(".")[-1] == name.asname:
+            yield _error_tuple(2023, node)
+
+
 def _i2040(node: ast.ImportFrom) -> Iterable[Tuple[int, int, str, type]]:
     """
     When using the from syntax, the import segment only contains one import.

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = flake8-import-restrictions
-version = 1.0.1
+version = 1.1.0
 description = A flake8 plugin used to disallow certain forms of imports.
 long_description = file: README.md
 long_description_content_type = text/markdown

tests/test_i2023.py

@@ -0,0 +1,27 @@
+from tests.util import BaseTest
+
+
+class Test_I2023(BaseTest):
+    def error_code(self) -> str:
+        return "I2023"
+
+    def test_pass_1(self):
+        code = """
+        from os import path
+        """
+        result = self.run_flake8(code)
+        assert result == []
+
+    def test_pass_2(self):
+        code = """
+        import os.path as ospath
+        """
+        result = self.run_flake8(code)
+        assert result == []
+
+    def test_fail_1(self):
+        code = """
+        import os.path as path
+        """
+        result = self.run_flake8(code)
+        self.assert_error_at(result, "I2023", 1, 1)