The ternary operator may be calculated incorrectly #19
Description
I'm using Rider 2020.2.4 with CognitiveComplexity 2020.2.2.
According to Campbell's "Cognitive Complexity" paper linked on the plugin's GitHub page, shorthand (i.e., MyObj myObj = a?.myObj;) should be ignored, however in the section "Increment for breaks in linear flow", the ternary operator is specifically included with if and other conditionals, and it seems like it should generate a structural increment.
Increment for breaks in the linear flow
Another guiding principle in the formulation of Cognitive Complexity is that structures that break code’s normal linear flow from top to bottom, left to right require maintainers to work harder to understand that code. In acknowledgement of this extra effort, Cognitive Complexity assesses structural increments for:
- Loop structures:
for,while,do while, ...- Conditionals: ternary operators,
if,#if,#ifdef, ...It assesses hybrid increments for:
else if,elif,else, …No nesting increment is assessed for these structures because the mental cost has already been paid when reading the
if.
The ?. and ?? shorthand operators seem like they should be ignored, but not ?:.
My understanding is that the entire ?: should be treated as a single structural increment, so when nested inside a for loop, it should cost +2, which is less than an equivalent if-else costs at +3 (+2 for the structural if and +1 for the hybrid else). When not nested, the ?: would have a cost of +1, and the if-else would cost +2 (+1 structural and +1 hybrid).
In short, the ?: shorthand is still encouraged over the if-else, however it should have a complexity cost.