IDE to Issue a Warning when Assignment Is Used Instead of Equality Comparison Operator when It's "Not Supposed to" Be Used

[Aks0121]

Is your feature request related to a problem? Please describe.
In my experience (and, as I gather, from the experiences of many), I've found that I spend hours trying to debug a script when I had apparently used an assignment operator instead of an equality comparison operator—with the lack of the extra '=' managing to evade me for a long time.

Describe the solution you'd like
When using an 'if statement' or a 'while loop' or any similar setup—where the assignment operator is apparently not used as widely as part of the conditions for those statements—the IDE would issue a warning if an assignment operator is used instead of an equality comparison operator.

For example,

if (someVariable = someValue){ }

would result in a warning that says (along the lines of) "are you sure you meant to use an assignment operator here"?

If I'm not mistaken, PyCharm already does this for Python.

Thank you for reading this!

[per1234]

GCC will provide a hint about this via the -Wparentheses warning, which you also get when using the -Wall flag:

E:\arduino\Wparentheses\Wparentheses.ino: In function 'void setup()':
E:\arduino\Wparentheses\Wparentheses.ino:4:20: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   if (someVariable = someValue){ }
       ~~~~~~~~~~~~~^~~~~~~~~~~

Not quite so helpful as what you suggested, but it at least brings your attention to the potential bug.

It is traditional to use the -Wall flag during the compilation when Arduino's compiler warnings preference is set to the "more" or "all" levels. Arduino Pro IDE is currently using the default "none" level (arduino/arduino-cli#684), where you get no compiler warnings at all and doesn't have a warnings level preference yet.

[per1234]

Compiler warnings can now be enabled via the File > Preferences > Compiler warnings menu.