function findConditionalAncestor(node) {
			let currentAncestor = node;

			do {
				if (isConditionalTestExpression(currentAncestor)) {
					return currentAncestor.parent;
				}
			} while (
				(currentAncestor = currentAncestor.parent) &&
				!astUtils.isFunction(currentAncestor)
			);

			return null;
		}
Given an AST node, perform a bottom-up search for the first ancestor that represents a conditional statement.
@param {!Object} node The node to use at the start of the search.
@returns {?Object} The closest ancestor node that represents a conditional statement.