Use single quote (') instead of quotation mark (") is only available with js/ts about ecocode HOT 3 OPEN

Reading the rule description in Frédéric Bordage's book, it is specifically targeted to PHP !
The rule should check if a string use double quotes without having variables in it.

The rule has no meanings in JS (doesn't matter) nor Rust / Java (different meaning)

In the future this could also apply to posix shell scripts too

from ecocode.

Concerning PHP, this might be the opportunity for a PHP-specific rule: don't use double quotes if you don't need the string to be interpreted.
Basically, if a string is interpreted, it will replace variables, beginning with a $ (e.g. "My name is $userName"). If there is no variable, asking PHP to interpret it seems to be redundant. Some checks would be required before deciding to make:

• Does a similar rule already exist in SonarQube? (a quick lookup through Sonarcloud rules seems to indicate that no, but a more thorough check would be welcome)
• Is there an optimization mechanism I don't know about that will prevent PHP from needlessly interpreting a String?

from ecocode.

True, I didn't read the book again. In JS/TS, it's mainly a style issue. In PHP, it does have an impact.

from ecocode.