function checkFunction(node) {
			const functionConfig = getConfigForFunction(node);

			if (functionConfig === "ignore") {
				return;
			}

			const rightToken = sourceCode.getFirstToken(
				node,
				astUtils.isOpeningParenToken,
			);
			const leftToken = sourceCode.getTokenBefore(rightToken);
			const hasSpacing = sourceCode.isSpaceBetweenTokens(
				leftToken,
				rightToken,
			);

			if (hasSpacing && functionConfig === "never") {
				context.report({
					node,
					loc: {
						start: leftToken.loc.end,
						end: rightToken.loc.start,
					},
					messageId: "unexpectedSpace",
					fix(fixer) {
						const comments =
							sourceCode.getCommentsBefore(rightToken);

						// Don't fix anything if there's a single line comment between the left and the right token
						if (comments.some(comment => comment.type === "Line")) {
							return null;
						}
						return fixer.replaceTextRange(
							[leftToken.range[1], rightToken.range[0]],
							comments.reduce(
								(text, comment) =>
									text + sourceCode.getText(comment),
								"",
							),
						);
					},
				});
			} else if (!hasSpacing && functionConfig === "always") {
				context.report({
					node,
					loc: rightToken.loc,
					messageId: "missingSpace",
					fix: fixer => fixer.insertTextAfter(leftToken, " "),
				});
			}
		}
Checks the parens of a function node
@param {ASTNode} node A function node
@returns {void}