eslint enforce space after the single-line-if parentheses

Question

I'm quite new to ESLint and I couldn't find a rule that does what I want. Consider the following code:

if(someCondition)i++;

I want to enforce a single space after the parentheses, so that we should have the following instead:

if(someCondition) i++;

However I simply couldn't find such a rule; it's not space-before-function-paren (obviously), keyword-spacing (which only affects the spacing after if) or space-before-blocks (since this is a single-line-if, there's no block). Please help. Thanks!

P.S. Same rule should apply to single-line-while as well.

Answer 1

As ESLint doesn't have such a rule and the policy says that they will no longer consider such proposals, I ended up writing my own rules as follows:

module.exports = {
    "single-line-control-statement-spacing": {
        meta: {
            type: "layout",
            docs: {
                description: "Enforces consistent spacing in single-line control statements.",
            },
            fixable: "whitespace",
        },
        create(context) {
            const sourceCode = context.getSourceCode();

            function checkSpaceAfter(node) {
                if(!node) return;
                if(node.loc.start.line !== node.loc.end.line) return; // Not single-line
                const body = node.consequent || node.body;
                const token = sourceCode.getFirstToken(body);
                const prev = sourceCode.getTokenBefore(token);
                const start = prev.range[1];
                const end = token.range[0];
                if(start === end) {
                    context.report({
                        loc: {
                            start: sourceCode.getLocFromIndex(start),
                            end: sourceCode.getLocFromIndex(end),
                        },
                        message: "There should be a single space after control statements.",
                        fix(fixer) {
                            return fixer.replaceTextRange([start, end], " ");
                        },
                    });
                }
            }

            return {
                IfStatement: checkSpaceAfter,
                DoWhileStatement: checkSpaceAfter,
                ForInStatement: checkSpaceAfter,
                ForOfStatement: checkSpaceAfter,
                ForStatement: checkSpaceAfter,
                WhileStatement: checkSpaceAfter,
            };
        },
    },
};

I then use eslint-plugin-local-rules to enable this rule in my project.