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

packages/opentelemetry-api/src/trace/NoopSpan.ts

@@ -75,12 +75,20 @@ export class NoopSpan implements Span {
   }
 
   // By default does nothing
-  end(endTime?: TimeInput): void {}
+  end(endTime?: TimeInput): void {
+    this._ended = true;
+  }
 
   // isRecording always returns false for noopSpan.
   isRecording(): boolean {
     return false;
   }
+
+  isEnded(): boolean {
+    return this._ended;
+  }
+
+  private _ended: boolean = false;
 }
 
 export const NOOP_SPAN = new NoopSpan();

packages/opentelemetry-api/src/trace/span.ts

@@ -100,4 +100,11 @@ export interface Span {
    * with the AddEvent operation and attributes using setAttributes.
    */
   isRecording(): boolean;
+
+  /**
+   * Returns if the span has been ended.
+   *
+   * @returns true if the Span has been ended.
+   */
+  isEnded(): boolean;
 }

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-stackdriver-trace/test/exporter.test.ts

@@ -108,6 +108,7 @@ describe('Stackdriver Trace Exporter', () => {
         duration: [32, 800000000],
         startTime: [1566156729, 709],
         endTime: [1566156731, 709],
+        ended: true,
         events: [],
         kind: types.SpanKind.CLIENT,
         links: [],
@@ -140,6 +141,7 @@ describe('Stackdriver Trace Exporter', () => {
         duration: [32, 800000000],
         startTime: [1566156729, 709],
         endTime: [1566156731, 709],
+        ended: true,
         events: [],
         kind: types.SpanKind.CLIENT,
         links: [],
@@ -171,6 +173,7 @@ describe('Stackdriver Trace Exporter', () => {
         duration: [32, 800000000],
         startTime: [1566156729, 709],
         endTime: [1566156731, 709],
+        ended: true,
         events: [],
         kind: types.SpanKind.CLIENT,
         links: [],
@@ -200,6 +203,7 @@ describe('Stackdriver Trace Exporter', () => {
         duration: [32, 800000000],
         startTime: [1566156729, 709],
         endTime: [1566156731, 709],
+        ended: true,
         events: [],
         kind: types.SpanKind.CLIENT,
         links: [],

packages/opentelemetry-exporter-stackdriver-trace/test/transform.test.ts

@@ -41,6 +41,7 @@ describe('transform', () => {
       duration: [32, 800000000],
       startTime: [1566156729, 709],
       endTime: [1566156731, 709],
+      ended: true,
       events: [],
       kind: types.SpanKind.CLIENT,
       links: [],

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

@@ -172,6 +172,10 @@ export class Span implements types.Span, ReadableSpan {
     return true;
   }
 
+  isEnded(): boolean {
+    return this._ended;
+  }
+
   toReadableSpan(): ReadableSpan {
     return this;
   }
@@ -180,6 +184,10 @@ 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);
+  });
 });