fix: pass sampler to Tracer instead of SpanCreator

* pass sampler to Tracer instead of SpanCreator

the SpanCreator doesn't accept a sampler property, and thus specifying a sampler had no effect

* update Changelog

Author: koenpunt

Changelog.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## NEXT
+
+* Fix sampler option. [#87](https://github.com/DanielMSchmidt/zipkin-javascript-opentracing/pull/87)
+
 ## 2.0.0
 
 * [Change carrier formats to be openzipkin ones](https://github.com/DanielMSchmidt/zipkin-javascript-opentracing/pull/72)

__mocks__/zipkin.js

@@ -124,7 +124,8 @@ module.exports = {
   },
   option: require("zipkin-option"),
   sampler: {
-    alwaysSampler: jest.fn(() => true)
+    alwaysSample: jest.fn(() => true),
+    Sampler: jest.fn()
   },
   jsonEncoder: {
     JSON_V1: jest.fn()

src/__tests__/index.js

@@ -2,7 +2,7 @@ const opentracing = require("opentracing");
 const Tracer = require("../index");
 const zipkin = require("zipkin");
 const {
-  option: { Some, None }
+  sampler: { Sampler }
 } = zipkin;
 
 describe("Opentracing interface", () => {
@@ -494,7 +494,8 @@ describe("Opentracing interface", () => {
 
       expect(zipkin.Tracer).toHaveBeenCalledWith({
         ctxImpl: {},
-        recorder: { id: 42 }
+        recorder: { id: 42 },
+        sampler: expect.any(Sampler)
       });
     });
   });

src/index.js

@@ -2,7 +2,6 @@ const {
   Annotation,
   BatchRecorder,
   ExplicitContext,
-  Request,
   TraceId,
   option: { Some, None },
   Tracer,
@@ -219,19 +218,20 @@ class Tracing {
       );
     }
 
-    options.sampler = options.sampler || sampler.alwaysSample;
+    options.sampler =
+      options.sampler || new sampler.Sampler(sampler.alwaysSample);
 
     this._serviceName = options.serviceName;
 
     this._zipkinTracer = new Tracer({
       ctxImpl: new ExplicitContext(),
-      recorder: options.recorder
+      recorder: options.recorder,
+      sampler: options.sampler
     });
     this._Span = SpanCreator({
       tracer: this._zipkinTracer,
       serviceName: this._serviceName,
-      kind: options.kind,
-      sampler: options.sampler
+      kind: options.kind
     });
   }