lib/rules/keyword-spacing.js
function checkSpacingForFunction(node) {
            const firstToken = node && sourceCode.getFirstToken(node);

            if (firstToken &&
                ((firstToken.type === "Keyword" && firstToken.value === "function") ||
                firstToken.value === "async")
            ) {
                checkSpacingBefore(firstToken);
            }
        }
function checkSpacingForFunction(node) {
            const firstToken = node && sourceCode.getFirstToken(node);

            if (firstToken &&
                ((firstToken.type === "Keyword" && firstToken.value === "function") ||
                firstToken.value === "async")
            ) {
                checkSpacingBefore(firstToken);
            }
        }
function checkSpacingForFunction ( node ) { const firstToken = node && sourceCode . getFirstToken ( node ) ; if ( firstToken && ( ( firstToken . type === "Keyword" && firstToken . value === "function" ) || firstToken . value === "async" ) ) { checkSpacingBefore ( firstToken ) ; } }
Reports `async` or `function` keywords of a given node if usage of
spacing around those keywords is invalid.

@param {ASTNode} node - A node to report.
@returns {void}
Reports async or function keywords of a given node if usage of spacing around those keywords is invalid .