Wemake-python-styleguide: Unnecessary literals

[orsinium]

Rule request

Thesis

Bad:

int()
float()
str()
bytes()
bool()
complex()

Good:

0
0.0
''
b''
False
0j

flake8-comprehensions does the same, but only for dict, list, and tuple.

Reasoning

There should be one-- and preferably only one --obvious way to do it.

[orsinium]

none = type(None)()
none is None  # True

:see_no_evil:

[orsinium]

Oh, also bytes() (use b'' instead).

[serhii73]

@sobolevn I can take this issue?
But can you please tell me what needs to do? Which the file and test need change and how it would be work?
Thank you.

[serhii73]

Also, plz, assign this issue to me on the GitHub UI. Thank you =)

[serhii73]

Sorry, @sobolevn what the files need change for resolve this issue?

[sobolevn]

Something about visitors/ast/functions.py I guess.

[serhii73]

First - I want to add a test and then add a code.

What the function will be showing an error after wrong-code in wemake_python_styleguide/visitors/ast/functions.py?

Do I need to add tests for this problem here - tests/test_visitors/test_ast/test_functions/test_wrong_function_calls.py?

[sobolevn]

Here: tests/test_visitors/test_ast/test_functions/test_unnecessary_literals.py
You have to create this file.

[sobolevn]

@serhii73 how's it going? Do you need any help from my side?

[serhii73]

Sorry, Nikita.
I will write to you in a few days.
I am a little busy this week.

[serhii73]

Hello @sobolevn How are you?

@pytest.mark.parametrize('expression', [
    'a = int()',
    'b = float()',
    'c = str()',
])
def test_unnecessary_literals(
    assert_errors,
    parse_ast_tree,
    expression,
    default_options,
):
    """Testing an error when we give unnecessary literals."""
    tree = parse_ast_tree(expression)

First I want create a test and then to write code in wemake_python_styleguide/visitors/ast/functions.py.

It is the top of my future test.
Then I need to add code as:

    visitor = SomeClass(default_options, tree=tree)
    visitor.run()

This is SomeClass from wemake_python_styleguide/violations/consistency.py ?
What the class from wemake_python_styleguide/violations/consistency.py I need to use in my test?
Do you know?
Thank you very much!

[sobolevn]

Well, you need at first to create a violation in consistency.py
Then you write a test, where:

• SomeClass is your visitor from functions.py
• You use your violation from consistency.py

[serhii73]

Ok, I need to change 3 files?
wemake_python_styleguide/visitors/ast/functions.py
tests/test_visitors/test_ast/test_functions/test_unnecessary_literals.py
wemake_python_styleguide/violations/consistency.py
Right?
In my test will be

tree = parse_ast_tree(expression)

Then I will create visitor

visitor = CLASS(default_options, tree=tree)
visitor.run()

This CLASS from what the file? From wemake_python_styleguide/visitors/ast/functions.py ? Right?

[serhii73]

@final
class UnnecessaryLiteralsViolation(ASTViolation):
    """
    """

    error_template = 'Unnecessary literals'
    code = 347

It is right class from wemake_python_styleguide/violations/consistency.py?

[serhii73]

@final
class UnnecessaryLiterals(base.BaseNodeVisitor):
    pass

This is a class from wemake_python_styleguide/visitors/ast/functions.py
What need to put in this class?

[orsinium]

Make it work, do tests, and put PR on review. We'll have a look and say if something wrong :+1: It's difficult to spot something in small pieces of code out of context.

[orsinium]

Also, merged PRs could be really helpful as an example of violations implementation.

[serhii73]

I got it.

[serhii73]

Hello @sobolevn How are you?
Can you, plz, un-assign this issue to me on the GitHub UI?
Because I tnink I don't have time this month for open source.
Maybe someone takes this issue and do it.
Sorry about that.
Happy Hacktoberfest!

[sobolevn]

No problem, @serhii73! Thanks for your help and your time. See you next month 🙂

[PrVrSs]

will do

[sobolevn]

Thanks, @PrVrSs!