yaml-unist-parser/lib/preprocess.js

A YAML parser that produces output compatible with unist

export function removeCstBlankLine(node) {
    switch (node.type) {
        case "DOCUMENT":
            for (let i = node.contents.length - 1; i >= 0; i--) {
                if (node.contents[i].type === "BLANK_LINE") {
                    node.contents.splice(i, 1);
                }
                else {
                    removeCstBlankLine(node.contents[i]);
                }
            }
            for (let i = node.directives.length - 1; i >= 0; i--) {
                if (node.directives[i].type === "BLANK_LINE") {
                    node.directives.splice(i, 1);
                }
            }
            break;
        case "FLOW_MAP":
        case "FLOW_SEQ":
        case "MAP":
        case "SEQ":
            for (let i = node.items.length - 1; i >= 0; i--) {
                const item = node.items[i];
                if ("char" in item) {
                    continue;
                }
                if (item.type === "BLANK_LINE") {
                    node.items.splice(i, 1);
                }
                else {
                    removeCstBlankLine(item);
                }
            }
            break;
        case "MAP_KEY":
        case "MAP_VALUE":
        case "SEQ_ITEM":
            if (node.node) {
                removeCstBlankLine(node.node);
            }
            break;
        case "ALIAS":
        case "BLANK_LINE":
        case "BLOCK_FOLDED":
        case "BLOCK_LITERAL":
        case "COMMENT":
        case "DIRECTIVE":
        case "PLAIN":
        case "QUOTE_DOUBLE":
        case "QUOTE_SINGLE":
            break;
        // istanbul ignore next
        default:
            throw new Error(`Unexpected node type ${JSON.stringify(node.type)}`);
    }
}