feat: make context.active() the default value for certain context functions

docs/tracing.md

@@ -84,20 +84,20 @@ async function onGet(request, response) {
 
  const userId = request.params.id;
 
- // Create a new context from the current context which has the span "active"
- const ctx = setSpan(context.active(), span);
- 
+ // Create a new context and set the span
+ const ctx = setSpan(span);
+
  // Call getUser with the newly created context
- // 
+ //
  // context.with calls a function with an associated "active" context. Within
  // the function, calling context.active() returns the currently active context.
  // If there is no active context, the ROOT_CONTEXT will be returned, which
  // has no key-value pairs.
- // 
+ //
  // context.with requires at least 2 arguments: a context and a function to be called.
  // If a third argument is provided, it will be bound to `this` `this` inside the function.
  // Any additional parameters are used as arguments when calling the function.
- // 
+ //
  // Return value is the value returned from getUser
  // | Context to be used as the "active" context
  // | | Function to be called

src/context/context.ts

@@ -15,7 +15,7 @@
  */
 
 import { Context } from './types';
-import { Baggage, Span, SpanContext } from '../';
+import { Baggage, context, Span, SpanContext } from '../';
 import { NoopSpan } from '../trace/NoopSpan';
 
 /**
@@ -39,20 +39,20 @@ const BAGGAGE_KEY = createContextKey('OpenTelemetry Baggage Key');
 /**
  * Return the span if one exists
  *
- * @param context context to get span from
+ * @param ctx context to get span from
  */
-export function getSpan(context: Context): Span | undefined {
- return (context.getValue(SPAN_KEY) as Span) || undefined;
+export function getSpan(ctx = context.active()): Span | undefined {
+ return (ctx.getValue(SPAN_KEY) as Span) || undefined;
 }
 
 /**
  * Set the span on a context
  *
- * @param context context to use as parent
- * @param span span to set active
+ * @param span to set
+ * @param ctx context to use as parent
  */
-export function setSpan(context: Context, span: Span): Context {
- return context.setValue(SPAN_KEY, span);
+export function setSpan(span: Span, ctx = context.active()): Context {
+ return ctx.setValue(SPAN_KEY, span);
 }
 
 /**
@@ -66,7 +66,7 @@ export function setSpanContext(
  context: Context,
  spanContext: SpanContext
 ): Context {
- return setSpan(context, new NoopSpan(spanContext));
+ return setSpan(new NoopSpan(spanContext), context);
 }
 
 /**
@@ -82,10 +82,10 @@ export function getSpanContext(context: Context): SpanContext | undefined {
  * Sets value on context to indicate that instrumentation should
  * be suppressed beyond this current scope.
  *
- * @param context context to set the suppress instrumentation value on.
+ * @param ctx context to set the suppress instrumentation value on.
  */
-export function suppressInstrumentation(context: Context): Context {
- return context.setValue(SUPPRESS_INSTRUMENTATION_KEY, true);
+export function suppressInstrumentation(ctx = context.active()): Context {
+ return ctx.setValue(SUPPRESS_INSTRUMENTATION_KEY, true);
 }
 
 /**
@@ -109,15 +109,15 @@ export function isInstrumentationSuppressed(context: Context): boolean {
 }
 
 /**
- * @param {Context} Context that manage all context values
+ * @param {Context} context that manage all context values
  * @returns {Baggage} Extracted baggage from the context
  */
 export function getBaggage(context: Context): Baggage | undefined {
  return (context.getValue(BAGGAGE_KEY) as Baggage) || undefined;
 }
 
 /**
- * @param {Context} Context that manage all context values
+ * @param {Context} context that manage all context values
  * @param {Baggage} baggage that will be set in the actual context
  */
 export function setBaggage(context: Context, baggage: Baggage): Context {