A demonstration of the trouble with dateline-crossing features. Without extra info it's unclear whether you mean the longest possible line or the shortest possible line. GitHub has the longer interpretation of my two lines, but I mean the shorter.
The bounding box recommendation in geojson/draft-geojson#42 gives software the extra info needed to interpret the geometries: I mean the geometry that fits in the box that has a SW corner at [170, 10] and a NW corner at [-170, 11].