Cannot read property 'spanId' of null

[pauldraper]

Please answer these questions before submitting a bug report.

What version of OpenTelemetry are you using?

0.12.0

What version of Node are you using?

6.14.4

Please provide the code you used to setup the OpenTelemetry SDK

What did you do?

const { NoopTracer } = require('@opentelemetry/api');
const tracer = new NoopTracer();
tracer.startSpan('example', {parent: null});

If possible, provide a recipe for reproducing the error.

What did you expect to see?

No error

What did you see instead?

TypeError: Cannot read property 'spanId' of null
    at isSpanContext (/home/paul/rivet/main/api/node_modules/@opentelemetry/api/build/src/trace/NoopTracer.js:58:27)
    at NoopTracer.startSpan (/home/paul/rivet/main/api/node_modules/@opentelemetry/api/build/src/trace/NoopTracer.js:36:13)

Additional context

[vmarchaud]

Closing since solution has been given in #1605