feat(core): Deprecate span toContext() and updateWithContext() (#10030)

These APIs are not really used, and are not compatible with
OpenTelemetry. So let's deprecate them for removal in v8.

Unless somebody knows a reason why we still need something like this?

Author: mydea

MIGRATION.md

@@ -8,6 +8,13 @@ npx @sentry/migr8@latest
 
 This will let you select which updates to run, and automatically update your code. Make sure to still review all code changes!
 
+## Deprecated fields on `Span` and `Transaction`
+
+In v8, the Span class is heavily reworked. The following properties & methods are thus deprecated:
+
+* `span.toContext()`: Access the fields directly instead.
+* `span.updateWithContext(newSpanContext)`: Update the fields directly instead.
+
 ## Deprecate `pushScope` & `popScope` in favor of `withScope`
 
 Instead of manually pushing/popping a scope, you should use `Sentry.withScope(callback: (scope: Scope))` instead.

packages/core/src/tracing/transaction.ts

@@ -149,6 +149,7 @@ export class Transaction extends SpanClass implements TransactionInterface {
    * @inheritDoc
    */
   public toContext(): TransactionContext {
+    // eslint-disable-next-line deprecation/deprecation
     const spanContext = super.toContext();
 
     return dropUndefinedKeys({
@@ -162,6 +163,7 @@ export class Transaction extends SpanClass implements TransactionInterface {
    * @inheritDoc
    */
   public updateWithContext(transactionContext: TransactionContext): this {
+    // eslint-disable-next-line deprecation/deprecation
     super.updateWithContext(transactionContext);
 
     this.name = transactionContext.name || '';

packages/types/src/span.ts

@@ -221,10 +221,16 @@ export interface Span extends SpanContext {
   /** Return a traceparent compatible header string */
   toTraceparent(): string;
 
-  /** Returns the current span properties as a `SpanContext` */
+  /**
+   * Returns the current span properties as a `SpanContext`.
+   * @deprecated Use `toJSON()` or access the fields directly instead.
+   */
   toContext(): SpanContext;
 
-  /** Updates the current span with a new `SpanContext` */
+  /**
+   * Updates the current span with a new `SpanContext`.
+   * @deprecated Update the fields directly instead.
+   */
   updateWithContext(spanContext: SpanContext): this;
 
   /** Convert the object to JSON for w. spans array info only */

packages/types/src/transaction.ts

@@ -102,10 +102,16 @@ export interface Transaction extends TransactionContext, Omit<Span, 'setName' |
    */
   setMeasurement(name: string, value: number, unit: MeasurementUnit): void;
 
-  /** Returns the current transaction properties as a `TransactionContext` */
+  /**
+   * Returns the current transaction properties as a `TransactionContext`.
+   * @deprecated Use `toJSON()` or access the fields directly instead.
+   */
   toContext(): TransactionContext;
 
-  /** Updates the current transaction with a new `TransactionContext` */
+  /**
+   * Updates the current transaction with a new `TransactionContext`.
+   * @deprecated Update the fields directly instead.
+   */
   updateWithContext(transactionContext: TransactionContext): this;
 
   /**