function toSourceNodeWhenNeeded()

in escodegen.js [508:530]


    function toSourceNodeWhenNeeded(generated, node) {
        if (!sourceMap) {
            // with no source maps, generated is either an
            // array or a string.  if an array, flatten it.
            // if a string, just return it
            if (Array.isArray(generated)) {
                return flattenToString(generated);
            } else {
                return generated;
            }
        }
        if (node == null) {
            if (generated instanceof SourceNode) {
                return generated;
            } else {
                node = {};
            }
        }
        if (node.loc == null) {
            return new SourceNode(null, null, sourceMap, generated, node.name || null);
        }
        return new SourceNode(node.loc.start.line, node.loc.start.column, (sourceMap === true ? node.loc.source || null : sourceMap), generated, node.name || null);
    }