feat: add ConsoleSpanExporter (open-telemetry#300)

Author: mayurkale22

Diff for: packages/opentelemetry-basic-tracer/src/export/ConsoleSpanExporter.ts

@@ -0,0 +1,44 @@
+/*!
+ * Copyright 2019, OpenTelemetry Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { SpanExporter } from './SpanExporter';
+import { ReadableSpan } from './ReadableSpan';
+import { ExportResult } from './ExportResult';
+import { hrTimeToMilliseconds } from '@opentelemetry/core';
+
+/**
+ * This is implementation of {@link SpanExporter} that prints spans to the
+ * console. This class can be used for diagnostic purposes.
+ */
+export class ConsoleSpanExporter implements SpanExporter {
+  export(
+    spans: ReadableSpan[],
+    resultCallback: (result: ExportResult) => void
+  ): void {
+    for (const span of spans) {
+      console.log(
+        `{name=${span.name}, traceId=${span.spanContext.traceId}, spanId=${
+          span.spanContext.spanId
+        }, kind=${span.kind}, parent=${
+          span.parentSpanId
+        }, duration=${hrTimeToMilliseconds(span.duration)}}}`
+      );
+    }
+    return resultCallback(ExportResult.SUCCESS);
+  }
+
+  shutdown(): void {}
+}

Diff for: packages/opentelemetry-basic-tracer/src/index.ts

@@ -15,6 +15,7 @@
  */
 
 export * from './BasicTracer';
+export * from './export/ConsoleSpanExporter';
 export * from './export/ExportResult';
 export * from './export/InMemorySpanExporter';
 export * from './export/ReadableSpan';