Rule proposal: prefer-ternary

[jmoore914]

This rule would enforce using ternary expressions to simple if/then/else statements.

Fail

if(condition){
  a = 1;
}
else{
  a = 2;
}

Pass

a = condition ? 1 : 2

if(condition){
  doSomeStuff()
  a = 1;
}
else{
  a = 2;
}

This rule could have options for whether it would be enabled for various situations (e.g. variable assignments, return statements, function calls).

I've already written this rule as a normal ESLint plugin so it would just need some minor rewriting to conform to the unicorn linting/documentation

[sindresorhus]

Accepted

[jmoore914]

Progress so far: https://github.com/jmoore914/eslint-plugin-unicorn/tree/prefer-ternary

Just need to find time to add documentation which might take a while because of all the different options available.