rspec/rules/S930/python/rule.adoc

== Why is this an issue?

Calling a function or a method with fewer or more arguments than expected will raise a ``++TypeError++``. This is usually a bug and should be fixed.

=== Noncompliant code example

[source,python]
----
######################
# Positional Arguments
######################

param_args = [1, 2, 3]
param_kwargs = {'x': 1, 'y': 2}

def func(a, b=1):
    print(a, b)

def positional_unlimited(a, b=1, *args):
    print(a, b, *args)

func(1)
func(1, 42)
func(1, 2, 3)  # Noncompliant. Too many positional arguments
func()  # Noncompliant. Missing positional argument for "a"

positional_unlimited(1, 2, 3, 4, 5)

def positional_limited(a, *, b=2):
    print(a, b)

positional_limited(1, 2)  # Noncompliant. Too many positional arguments


#############################
# Unexpected Keyword argument
#############################

def keywords(a=1, b=2, *, c=3):
    print(a, b, c)

keywords(1)
keywords(1, z=42)  # Noncompliant. Unexpected keyword argument "z"

def keywords_unlimited(a=1, b=2, *, c=3, **kwargs):
    print(a, b, kwargs)

keywords_unlimited(a=1, b=2, z=42)

#################################
# Mandatory Keyword argument only
#################################

def mandatory_keyword(a, *, b):
    print(a, b)

mandatory_keyword(1, b=2)
mandatory_keyword(1)  # Noncompliant. Missing keyword argument "b"
----

include::../see.adoc[]

ifdef::env-github,rspecator-view[]

'''
== Implementation Specification
(visible only on this page)

=== Message

* When there is one or more unexpected positional argument: "Remove XXX unexpected argument; 'foo' expects YYY positional arguments."
* When there is one or more unexpected named argument: "Remove this unexpected named argument X"
* When the maximum number of positional arguments is reached and {empty}*args is given: "Remove "*XXX"; maximum number of positional arguments already reached."
* When the maximum number of keyword arguments is reached and {empty}*{empty}*kwargs is given: "Remove "**XXX"; maximum number of keyword arguments already reached."
* When there are missing positional arguments: "Add XXX missing arguments; 'foo' expects YYY positional arguments."
* When there are missing keyword arguments: "Add the missing keyword argument XXX"


=== Highlighting

Primary: The function name

Secondary:

* The function definition


'''
== Comments And Links
(visible only on this page)

include::../comments-and-links.adoc[]

endif::env-github,rspecator-view[]