feat: introduce ended property on Span

Add a getter to Span and ReadableSpan to allow checking if the span is
ended without using a private field or rely on internals like
span.duration[0] < 0.

Refs: open-telemetry/opentelemetry-java#693
Refs: open-telemetry/opentelemetry-java#697

Author: Flarna

packages/opentelemetry-exporter-collector/test/helper.ts

@@ -32,6 +32,7 @@ export const mockedReadableSpan: ReadableSpan = {
   parentSpanId: '78a8915098864388',
   startTime: [1574120165, 429803070],
   endTime: [1574120165, 438688070],
+  ended: true,
   status: { code: 0 },
   attributes: { component: 'document-load' },
   links: [

packages/opentelemetry-exporter-jaeger/test/jaeger.test.ts

@@ -117,6 +117,7 @@ describe('JaegerExporter', () => {
         spanContext,
         startTime: [1566156729, 709],
         endTime: [1566156731, 709],
+        ended: true,
         status: {
           code: types.CanonicalCode.DATA_LOSS,
         },

packages/opentelemetry-exporter-jaeger/test/transform.test.ts

@@ -35,6 +35,7 @@ describe('transform', () => {
         spanContext,
         startTime: [1566156729, 709],
         endTime: [1566156731, 709],
+        ended: true,
         status: {
           code: types.CanonicalCode.OK,
         },
@@ -131,6 +132,7 @@ describe('transform', () => {
         spanContext,
         startTime: [1566156729, 709],
         endTime: [1566156731, 709],
+        ended: true,
         status: {
           code: types.CanonicalCode.DATA_LOSS,
           message: 'data loss',
@@ -187,6 +189,7 @@ describe('transform', () => {
         spanContext,
         startTime: [1566156729, 709],
         endTime: [1566156731, 709],
+        ended: true,
         status: {
           code: types.CanonicalCode.OK,
         },

packages/opentelemetry-exporter-zipkin/test/zipkin.test.ts

@@ -38,6 +38,7 @@ function getReadableSpan() {
     },
     startTime: [startTime, 0],
     endTime: [startTime + duration, 0],
+    ended: true,
     duration: [duration, 0],
     status: {
       code: types.CanonicalCode.OK,
@@ -141,6 +142,7 @@ describe('ZipkinExporter', () => {
         },
         startTime: [startTime, 0],
         endTime: [startTime + duration, 0],
+        ended: true,
         duration: [duration, 0],
         status: {
           code: types.CanonicalCode.OK,
@@ -167,6 +169,7 @@ describe('ZipkinExporter', () => {
         },
         startTime: [startTime, 0],
         endTime: [startTime + duration, 0],
+        ended: true,
         duration: [duration, 0],
         status: {
           code: types.CanonicalCode.OK,

packages/opentelemetry-tracing/src/Span.ts

@@ -180,6 +180,10 @@ export class Span implements types.Span, ReadableSpan {
     return this._duration;
   }
 
+  get ended(): boolean {
+    return this._ended;
+  }
+
   private _isSpanEnded(): boolean {
     if (this._ended) {
       this._logger.warn(

packages/opentelemetry-tracing/src/export/ReadableSpan.ts

@@ -36,4 +36,5 @@ export interface ReadableSpan {
   readonly links: Link[];
   readonly events: TimedEvent[];
   readonly duration: HrTime;
+  readonly ended: boolean;
 }

packages/opentelemetry-tracing/test/Span.test.ts

@@ -349,4 +349,11 @@ describe('Span', () => {
     span.updateName('bar-span');
     assert.strictEqual(span.name, 'foo-span');
   });
+
+  it('should have ended', () => {
+    const span = new Span(tracer, name, spanContext, SpanKind.SERVER);
+    assert.strictEqual(span.ended, false);
+    span.end();
+    assert.strictEqual(span.ended, true);
+  })
 });