Explicit returns mixed with implicit (fall through) returns — CodeQL query help documentation
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Explicit returns mixed with implicit (fall through) returns
ID: py/mixed-returns
Kind: problem
Security severity:
Severity: recommendation
Precision: high
Tags:
- quality
- reliability
- correctness
Query suites:
- python-code-quality.qls
- python-security-and-quality.qls
Click to see the query in the CodeQL repository
When a function contains both explicit returns (return value) and implicit returns (where code falls off the end of a function), this often indicates that a return statement has been forgotten. It is best to return an explicit return value even when returning None because this makes it easier for other developers to read your code.
Recommendation
Add an explicit return at the end of the function.
Example
In the check_state1 function, the developer probably did intend to use an implicit return value of None as this equates to False. However, the function in check_state2 is easier to read.
def check_state1(state, interactive=True):
if not state['good'] or not state['bad']:
if (good or bad or skip or reset) and interactive:
return # implicitly return None
if not state['good']:
raise util.Abort(_('cannot bisect (no known good revisions)'))
else:
raise util.Abort(_('cannot bisect (no known bad revisions)'))
return True
def check_state2(state, interactive=True):
if not state['good'] or not state['bad']:
if (good or bad or skip or reset) and interactive:
return False # return an explicit value
if not state['good']:
raise util.Abort(_('cannot bisect (no known good revisions)'))
else:
raise util.Abort(_('cannot bisect (no known bad revisions)'))
return True
References