fix: send stringified _MS_Links (#42)

examples/basic-tracer-node/package.json

@@ -31,7 +31,7 @@
   },
   "dependencies": {
     "@azure/monitor-opentelemetry-exporter": "^1.0.0-preview.2",
-    "@opentelemetry/api": "^0.8.1",
+    "@opentelemetry/api": "^0.9.0",
     "@opentelemetry/tracing": "^0.9.0"
   },
   "homepage": "https://github.com/open-telemetry/opentelemetry-js#readme"

package.json

@@ -12,18 +12,18 @@
     "publish": "lerna run publish"
   },
   "devDependencies": {
-    "@opentelemetry/api": "^0.8.3",
+    "@opentelemetry/api": "^0.9.0",
     "@opentelemetry/tracing": "^0.9.0",
     "@types/mocha": "^7.0.2",
-    "@types/node": "^14.0.13",
+    "@types/node": "^14.0.14",
     "@typescript-eslint/eslint-plugin": "^2.34.0",
-    "c8": "^7.1.2",
+    "c8": "^7.2.0",
     "eslint": "^6.8.0",
     "eslint-config-airbnb-typescript": "^7.2.0",
     "eslint-config-prettier": "^6.10.1",
     "eslint-plugin-import": "^2.21.2",
     "eslint-plugin-node": "^11.1.0",
-    "eslint-plugin-prettier": "^3.1.2",
+    "eslint-plugin-prettier": "^3.1.4",
     "lerna": "^3.22.1",
     "mocha": "^7.2.0",
     "nock": "^12.0.3",

packages/azure-opentelemetry-exporter/src/utils/spanUtils.ts

@@ -61,7 +61,10 @@ function createPropertiesFromSpan(span: ReadableSpan): Properties {
     id: link.context.spanId,
   }));
 
-  properties[MS_LINKS] = links;
+  if (links.length > 0) {
+    properties[MS_LINKS] = JSON.stringify(links);
+  }
+
   return properties;
 }
 

packages/azure-opentelemetry-exporter/test/utils/spanUtils.test.ts

@@ -81,7 +81,6 @@ describe('spanUtils.ts', () => {
           'extra.attribute': 'foo',
           [grpc.GRPC_ERROR_MESSAGE]: 'some error message',
           [grpc.GRPC_ERROR_NAME]: 'some error name',
-          [ai.MS_LINKS]: [],
         };
 
         const expectedBaseData: Partial<RequestData> = {
@@ -135,7 +134,6 @@ describe('spanUtils.ts', () => {
           'extra.attribute': 'foo',
           [grpc.GRPC_ERROR_MESSAGE]: 'some error message',
           [grpc.GRPC_ERROR_NAME]: 'some error name',
-          [ai.MS_LINKS]: [],
         };
 
         const expectedBaseData: Partial<RemoteDependencyData> = {
@@ -186,7 +184,6 @@ describe('spanUtils.ts', () => {
         };
         const expectedProperties: Properties = {
           'extra.attribute': 'foo',
-          [ai.MS_LINKS]: [],
         };
 
         const expectedBaseData: Partial<RequestData> = {
@@ -234,7 +231,6 @@ describe('spanUtils.ts', () => {
         };
         const expectedProperties: Properties = {
           'extra.attribute': 'foo',
-          [ai.MS_LINKS]: [],
         };
 
         const expectedBaseData: Partial<RemoteDependencyData> = {
@@ -289,7 +285,6 @@ describe('spanUtils.ts', () => {
         };
         const expectedProperties: Properties = {
           'extra.attribute': 'foo',
-          [ai.MS_LINKS]: [],
         };
 
         const expectedBaseData: RequestData = {
@@ -339,7 +334,6 @@ describe('spanUtils.ts', () => {
         };
         const expectedProperties: Properties = {
           'extra.attribute': 'foo',
-          [ai.MS_LINKS]: [],
         };
 
         const expectedBaseData: RemoteDependencyData = {