From 5423518647350a5a11a1ca859f82aefabfed4844 Mon Sep 17 00:00:00 2001
From: Niek Kruse <niek@messagebird.com>
Date: Fri, 2 Apr 2021 10:03:28 +0200
Subject: [PATCH] docs(instrumentation-fetch): document
 applyCustomAttributesOnSpan

---
 packages/opentelemetry-instrumentation-fetch/README.md    | 8 ++++++++
 packages/opentelemetry-instrumentation-fetch/src/fetch.ts | 5 +----
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/packages/opentelemetry-instrumentation-fetch/README.md b/packages/opentelemetry-instrumentation-fetch/README.md
index 13bfec30e46..a18a364f343 100644
--- a/packages/opentelemetry-instrumentation-fetch/README.md
+++ b/packages/opentelemetry-instrumentation-fetch/README.md
@@ -59,6 +59,14 @@ fetch('http://localhost:8090/fetch.js');
 
 See [examples/tracer-web/fetch](https://github.com/open-telemetry/opentelemetry-js/tree/main/examples/tracer-web) for a short example.
 
+### Fetch Instrumentation options
+
+Fetch instrumentation plugin has few options available to choose from. You can set the following:
+
+| Options                                                                                                                                           | Type                          | Description                           |
+| ------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------- | ------------------------------------- |
+| [`applyCustomAttributesOnSpan`](https://github.com/open-telemetry/opentelemetry-js/blob/main/packages/opentelemetry-instrumentation-fetch/src/fetch.ts#L47) | `HttpCustomAttributeFunction` | Function for adding custom attributes |
+
 ## Useful links
 
 - For more information on OpenTelemetry, visit: <https://opentelemetry.io/>
diff --git a/packages/opentelemetry-instrumentation-fetch/src/fetch.ts b/packages/opentelemetry-instrumentation-fetch/src/fetch.ts
index 6bb40800de7..c843e7c6579 100644
--- a/packages/opentelemetry-instrumentation-fetch/src/fetch.ts
+++ b/packages/opentelemetry-instrumentation-fetch/src/fetch.ts
@@ -198,7 +198,7 @@ export class FetchInstrumentation extends InstrumentationBase<
     }
     const method = (options.method || 'GET').toUpperCase();
     const spanName = `HTTP ${method}`;
-    const span = this.tracer.startSpan(spanName, {
+    return this.tracer.startSpan(spanName, {
       kind: api.SpanKind.CLIENT,
       attributes: {
         [AttributeNames.COMPONENT]: this.moduleName,
@@ -206,8 +206,6 @@ export class FetchInstrumentation extends InstrumentationBase<
         [HttpAttribute.HTTP_URL]: url,
       },
     });
-
-    return span;
   }
 
   /**
@@ -320,7 +318,6 @@ export class FetchInstrumentation extends InstrumentationBase<
         ) {
           try {
             plugin._applyAttributesAfterFetch(span, options, response);
-
             if (response.status >= 200 && response.status < 400) {
               plugin._endSpan(span, spanData, response);
             } else {