SIM905: Add rule to explictly create a list (#98)

No string splitting anymore.

This will be SIM225 once the trial period is over

Closes #86

README.md

@@ -48,7 +48,8 @@ Python-specific rules:
 * [`SIM117`](https://github.com/MartinThoma/flake8-simplify/issues/35): Merge with-statements that use the same scope ([example](#SIM117))
 * [`SIM119`](https://github.com/MartinThoma/flake8-simplify/issues/37) ![](https://shields.io/badge/-legacyfix-inactive): Use dataclasses for data containers ([example](#SIM119))
 * `SIM120` ![](https://shields.io/badge/-legacyfix-inactive): Use 'class FooBar:' instead of 'class FooBar(object):' ([example](#SIM120))
-* `SIM124`: Reserved for SIM904 once it's stable
+* `SIM124`: Reserved for [SIM904](#sim904) once it's stable
+* `SIM125`: Reserved for [SIM905](#sim905) once it's stable
 
 Simplifying Comparations:
 
@@ -67,7 +68,7 @@ Simplifying Comparations:
 * [`SIM221`](https://github.com/MartinThoma/flake8-simplify/issues/6): Use 'True' instead of 'a or not a' ([example](#SIM221))
 * [`SIM222`](https://github.com/MartinThoma/flake8-simplify/issues/6): Use 'True' instead of '... or True' ([example](#SIM222))
 * [`SIM223`](https://github.com/MartinThoma/flake8-simplify/issues/6): Use 'False' instead of '... and False' ([example](#SIM223))
-* [`SIM224`](https://github.com/MartinThoma/flake8-simplify/issues/88): Reserved for SIM901 once it's stable
+* [`SIM224`](https://github.com/MartinThoma/flake8-simplify/issues/88): Reserved for [SIM901](#sim901) once it's stable
 * [`SIM300`](https://github.com/MartinThoma/flake8-simplify/issues/16): Use 'age == 42' instead of '42 == age' ([example](#SIM300))
 
 Simplifying usage of dictionaries:
@@ -94,6 +95,7 @@ Current experimental rules:
 
 * `SIM901`: Use comparisons directly instead of wrapping them in a `bool(...)` call ([example](#SIM901))
 * `SIM904`: Assign values to dictionary directly at initialization ([example](#SIM904))
+* [`SIM905`](https://github.com/MartinThoma/flake8-simplify/issues/86): Split string directly if only constants are used ([example](#SIM905))
 
 ## Disabling Rules
 
@@ -550,6 +552,12 @@ a == b
 
 ### SIM904
 
+This rule will be renamed to `SIM224` after its 6-month trial period is over.
+Please report any issues you encounter with this rule!
+
+The trial period starts on 12th of February and will end on 12th of September 2022.
+
+
 ```python
 # Bad
 a = {}
@@ -558,3 +566,18 @@ a["b"] = "c"
 # Good
 a = {"b": "c"}
 ```
+
+### SIM905
+
+This rule will be renamed to `SIM225` after its 6-month trial period is over.
+Please report any issues you encounter with this rule!
+
+The trial period starts on 13th of February and will end on 13th of September 2022.
+
+```python
+# Bad
+domains = "de com net org".split()
+
+# Good
+domains = ["de", "com", "net", "org"]
+```

flake8_simplify.py

@@ -1,6 +1,7 @@
 # Core Library
 import ast
 import itertools
+import json
 import sys
 from collections import defaultdict
 from typing import (
@@ -109,6 +110,7 @@ def __init__(self, orig: ast.Call) -> None:
 )
 SIM901 = "SIM901 Use '{better}' instead of '{current}'"
 SIM904 = "SIM904 Initialize dictionary '{dict_name}' directly"
+SIM905 = "SIM905 Use '{expected}' instead of '{actual}'"
 
 # ast.Constant in Python 3.8, ast.NameConstant in Python 3.6 and 3.7
 BOOL_CONST_TYPES = (ast.Constant, ast.NameConstant)
@@ -1896,6 +1898,32 @@ def _get_sim904(node: ast.Assign) -> List[Tuple[int, int, str]]:
     return errors
 
 
+def _get_sim905(node: ast.Call) -> List[Tuple[int, int, str]]:
+    errors: List[Tuple[int, int, str]] = []
+    if not (
+        isinstance(node.func, ast.Attribute)
+        and node.func.attr == "split"
+        and isinstance(node.func.value, (ast.Str, ast.Constant))
+    ):
+        return errors
+
+    if isinstance(node.func.value, ast.Constant):
+        value = node.func.value.value
+    else:
+        value = node.func.value.s
+
+    expected = json.dumps(value.split())
+    actual = to_source(node.func.value) + ".split()"
+    errors.append(
+        (
+            node.lineno,
+            node.col_offset,
+            SIM905.format(expected=expected, actual=actual),
+        )
+    )
+    return errors
+
+
 class Visitor(ast.NodeVisitor):
     def __init__(self) -> None:
         self.errors: List[Tuple[int, int, str]] = []
@@ -1907,6 +1935,7 @@ def visit_Assign(self, node: ast.Assign) -> Any:
     def visit_Call(self, node: ast.Call) -> Any:
         self.errors += _get_sim115(Call(node))
         self.errors += _get_sim901(node)
+        self.errors += _get_sim905(node)
         self.generic_visit(node)
 
     def visit_With(self, node: ast.With) -> Any:

tests/test_simplify.py

@@ -943,3 +943,11 @@ def test_sim904():
 a['b'] = 'c'"""
     )
     assert results == {"1:0 SIM904 Initialize dictionary 'a' directly"}
+
+
+def test_sim905():
+    results = _results("""domains = "de com net org".split()""")
+    assert results == {
+        '1:10 SIM905 Use \'["de", "com", "net", "org"]\' '
+        "instead of '\"de com net org\".split()'"
+    }