End stream within map()

[bradserbu]

How can I force a stream to end from within a map() function?

Scenario:

• Processing a very large stream of data
• Calling a promise via .map($(promise)).merge()
• The promise called above is to an external API that has a hard QUERY LIMIT.
• When the query limit is detected (via value on the stream === QUERY_LIMIT_MESSAGE), I would like to terminate all processing.

[vqvu]

Implement a custom consume handler that checks for QUERY_LIMIT_MESSAGE and pushes nil.

stream.map($(promise))
    .merge()
    .consume((err, x, push, next) => {
        if (x === _.nil || x === QUERY_LIMIT_MESSAGE) {
            push(null, _.nil);
        } else{
            push(err, x);
            next();
        }
    })

[bradserbu]

Would this propagate the .end() back to the source stream?