TypeError: span.toJSON is not a function

This issue gets thrown if a span is being modified (annotation is added) after span has already been finished. Reason is the span will both have endTimestamp and would be removed from partialSpans in batch-recorder.js. This would trigger following sequence of calls (in packages/zipkin/src/batch-recorder.js):

if (span.endTimestamp) {
  this._writeSpan(id);

Source: https://github.com/openzipkin/zipkin-js/blob/master/packages/zipkin/src/batch-recorder.js#L48-L49

and then

_writeSpan(id) {
  const span = this.partialSpans.get(id); // this.partialSpans.get(id) will return undefined

Source: https://github.com/openzipkin/zipkin-js/blob/master/packages/zipkin/src/batch-recorder.js#L41-L42

[codefromthecrypt]

I think easiest way is to put in a unit test for data added after span finished. then make sure it doesn’t raise error. not raising error is most important thing

[jcchavezs]

This might not happen anymore as we now check if the retrieved span is undefined: https://github.com/openzipkin/zipkin-js/blob/aff41209df70502fe8ab09f60a6a0b4a7e4236bd/packages/zipkin/src/batch-recorder.js#L114