feat(metrics): Add top level option enableMetrics and beforeSendMetric (#18088)

- Adds top level options for `enableMetrics` and `beforeSendMetric`.
- Kept the experimental flags for now to stay backwards compatible, but
added a deprecation note and todo comments for removing them in v11.
- Updated all the tests to use the top-level flag.
- Had to refactor the `_INTERNAL_captureMetric` function since it broke
the complexity threshold of our linter

> [!WARNING]  
> `enableMetrics` now defaults to `true`, so theoretically this PR is
behaviourally breaking.

Author: chargome

.size-limit.js

@@ -190,7 +190,7 @@ module.exports = [
     path: createCDNPath('bundle.tracing.min.js'),
     gzip: false,
     brotli: false,
-    limit: '124.1 KB',
+    limit: '125 KB',
   },
   {
     name: 'CDN Bundle (incl. Tracing, Replay) - uncompressed',

dev-packages/browser-integration-tests/suites/public-api/metrics/init.js

@@ -4,9 +4,6 @@ window.Sentry = Sentry;
 
 Sentry.init({
   dsn: 'https://[email protected]/1337',
-  _experiments: {
-    enableMetrics: true,
-  },
   release: '1.0.0',
   environment: 'test',
   integrations: integrations => {

dev-packages/node-core-integration-tests/suites/public-api/metrics/scenario.ts

@@ -6,9 +6,6 @@ const client = Sentry.init({
   dsn: 'https://[email protected]/1337',
   release: '1.0.0',
   environment: 'test',
-  _experiments: {
-    enableMetrics: true,
-  },
   transport: loggingTransport,
 });
 

dev-packages/node-integration-tests/suites/public-api/metrics/scenario.ts

@@ -5,9 +5,6 @@ Sentry.init({
   dsn: 'https://[email protected]/1337',
   release: '1.0.0',
   environment: 'test',
-  _experiments: {
-    enableMetrics: true,
-  },
   transport: loggingTransport,
 });
 

packages/browser/src/client.ts

@@ -104,10 +104,22 @@ export class BrowserClient extends Client<BrowserClientOptions> {
 
     super(opts);
 
-    const { sendDefaultPii, sendClientReports, enableLogs, _experiments } = this._options;
+    const {
+      sendDefaultPii,
+      sendClientReports,
+      enableLogs,
+      _experiments,
+      enableMetrics: enableMetricsOption,
+    } = this._options;
+
+    // todo(v11): Remove the experimental flag
+    // eslint-disable-next-line deprecation/deprecation
+    const enableMetrics = enableMetricsOption ?? _experiments?.enableMetrics ?? true;
 
     // Flush logs and metrics when page becomes hidden (e.g., tab switch, navigation)
-    if (WINDOW.document && (sendClientReports || enableLogs || _experiments?.enableMetrics)) {
+    // todo(v11): Remove the experimental flag
+    // eslint-disable-next-line deprecation/deprecation
+    if (WINDOW.document && (sendClientReports || enableLogs || enableMetrics)) {
       WINDOW.document.addEventListener('visibilitychange', () => {
         if (WINDOW.document.visibilityState === 'hidden') {
           if (sendClientReports) {
@@ -116,7 +128,8 @@ export class BrowserClient extends Client<BrowserClientOptions> {
           if (enableLogs) {
             _INTERNAL_flushLogsBuffer(this);
           }
-          if (_experiments?.enableMetrics) {
+
+          if (enableMetrics) {
             _INTERNAL_flushMetricsBuffer(this);
           }
         }

packages/core/src/client.ts

@@ -232,8 +232,12 @@ export abstract class Client<O extends ClientOptions = ClientOptions> {
       setupWeightBasedFlushing(this, 'afterCaptureLog', 'flushLogs', estimateLogSizeInBytes, _INTERNAL_flushLogsBuffer);
     }
 
+    // todo(v11): Remove the experimental flag
+    // eslint-disable-next-line deprecation/deprecation
+    const enableMetrics = this._options.enableMetrics ?? this._options._experiments?.enableMetrics ?? true;
+
     // Setup metric flushing with weight and timeout tracking
-    if (this._options._experiments?.enableMetrics) {
+    if (enableMetrics) {
       setupWeightBasedFlushing(
         this,
         'afterCaptureMetric',

packages/core/src/metrics/internal.ts

@@ -116,49 +116,33 @@ export interface InternalCaptureMetricOptions {
 }
 
 /**
- * Captures a metric event and sends it to Sentry.
- *
- * @param metric - The metric event to capture.
- * @param options - Options for capturing the metric.
- *
- * @experimental This method will experience breaking changes. This is not yet part of
- * the stable Sentry SDK API and can be changed or removed without warning.
+ * Enriches metric with all contextual attributes (user, SDK metadata, replay, etc.)
  */
-export function _INTERNAL_captureMetric(beforeMetric: Metric, options?: InternalCaptureMetricOptions): void {
-  const currentScope = options?.scope ?? getCurrentScope();
-  const captureSerializedMetric = options?.captureSerializedMetric ?? _INTERNAL_captureSerializedMetric;
-  const client = currentScope?.getClient() ?? getClient();
-  if (!client) {
-    DEBUG_BUILD && debug.warn('No client available to capture metric.');
-    return;
-  }
-
-  const { release, environment, _experiments } = client.getOptions();
-  if (!_experiments?.enableMetrics) {
-    DEBUG_BUILD && debug.warn('metrics option not enabled, metric will not be captured.');
-    return;
-  }
-
-  const [, traceContext] = _getTraceInfoFromScope(client, currentScope);
+function _enrichMetricAttributes(beforeMetric: Metric, client: Client, currentScope: Scope): Metric {
+  const { release, environment } = client.getOptions();
 
   const processedMetricAttributes = {
     ...beforeMetric.attributes,
   };
 
+  // Add user attributes
   const {
     user: { id, email, username },
   } = getMergedScopeData(currentScope);
   setMetricAttribute(processedMetricAttributes, 'user.id', id, false);
   setMetricAttribute(processedMetricAttributes, 'user.email', email, false);
   setMetricAttribute(processedMetricAttributes, 'user.name', username, false);
 
+  // Add Sentry metadata
   setMetricAttribute(processedMetricAttributes, 'sentry.release', release);
   setMetricAttribute(processedMetricAttributes, 'sentry.environment', environment);
 
+  // Add SDK metadata
   const { name, version } = client.getSdkMetadata()?.sdk ?? {};
   setMetricAttribute(processedMetricAttributes, 'sentry.sdk.name', name);
   setMetricAttribute(processedMetricAttributes, 'sentry.sdk.version', version);
 
+  // Add replay metadata
   const replay = client.getIntegrationByName<
     Integration & {
       getReplayId: (onlyIfSampled?: boolean) => string;
@@ -167,54 +151,97 @@ export function _INTERNAL_captureMetric(beforeMetric: Metric, options?: Internal
   >('Replay');
 
   const replayId = replay?.getReplayId(true);
-
   setMetricAttribute(processedMetricAttributes, 'sentry.replay_id', replayId);
 
   if (replayId && replay?.getRecordingMode() === 'buffer') {
-    // We send this so we can identify cases where the replayId is attached but the replay itself might not have been sent to Sentry
     setMetricAttribute(processedMetricAttributes, 'sentry._internal.replay_is_buffering', true);
   }
 
-  const metric: Metric = {
+  return {
     ...beforeMetric,
     attributes: processedMetricAttributes,
   };
+}
 
-  // Run beforeSendMetric callback
-  const processedMetric = _experiments?.beforeSendMetric ? _experiments.beforeSendMetric(metric) : metric;
-
-  if (!processedMetric) {
-    DEBUG_BUILD && debug.log('`beforeSendMetric` returned `null`, will not send metric.');
-    return;
-  }
-
+/**
+ * Creates a serialized metric ready to be sent to Sentry.
+ */
+function _buildSerializedMetric(metric: Metric, client: Client, currentScope: Scope): SerializedMetric {
+  // Serialize attributes
   const serializedAttributes: Record<string, SerializedMetricAttributeValue> = {};
-  for (const key in processedMetric.attributes) {
-    if (processedMetric.attributes[key] !== undefined) {
-      serializedAttributes[key] = metricAttributeToSerializedMetricAttribute(processedMetric.attributes[key]);
+  for (const key in metric.attributes) {
+    if (metric.attributes[key] !== undefined) {
+      serializedAttributes[key] = metricAttributeToSerializedMetricAttribute(metric.attributes[key]);
     }
   }
 
+  // Get trace context
+  const [, traceContext] = _getTraceInfoFromScope(client, currentScope);
   const span = _getSpanForScope(currentScope);
   const traceId = span ? span.spanContext().traceId : traceContext?.trace_id;
   const spanId = span ? span.spanContext().spanId : undefined;
 
-  const serializedMetric: SerializedMetric = {
+  return {
     timestamp: timestampInSeconds(),
     trace_id: traceId ?? '',
     span_id: spanId,
-    name: processedMetric.name,
-    type: processedMetric.type,
-    unit: processedMetric.unit,
-    value: processedMetric.value,
+    name: metric.name,
+    type: metric.type,
+    unit: metric.unit,
+    value: metric.value,
     attributes: serializedAttributes,
   };
+}
+
+/**
+ * Captures a metric event and sends it to Sentry.
+ *
+ * @param metric - The metric event to capture.
+ * @param options - Options for capturing the metric.
+ *
+ * @experimental This method will experience breaking changes. This is not yet part of
+ * the stable Sentry SDK API and can be changed or removed without warning.
+ */
+export function _INTERNAL_captureMetric(beforeMetric: Metric, options?: InternalCaptureMetricOptions): void {
+  const currentScope = options?.scope ?? getCurrentScope();
+  const captureSerializedMetric = options?.captureSerializedMetric ?? _INTERNAL_captureSerializedMetric;
+  const client = currentScope?.getClient() ?? getClient();
+  if (!client) {
+    DEBUG_BUILD && debug.warn('No client available to capture metric.');
+    return;
+  }
+
+  const { _experiments, enableMetrics, beforeSendMetric } = client.getOptions();
+
+  // todo(v11): Remove the experimental flag
+  // eslint-disable-next-line deprecation/deprecation
+  const metricsEnabled = enableMetrics ?? _experiments?.enableMetrics ?? true;
+
+  if (!metricsEnabled) {
+    DEBUG_BUILD && debug.warn('metrics option not enabled, metric will not be captured.');
+    return;
+  }
+
+  // Enrich metric with contextual attributes
+  const enrichedMetric = _enrichMetricAttributes(beforeMetric, client, currentScope);
+
+  // todo(v11): Remove the experimental `beforeSendMetric`
+  // eslint-disable-next-line deprecation/deprecation
+  const beforeSendCallback = beforeSendMetric || _experiments?.beforeSendMetric;
+  const processedMetric = beforeSendCallback ? beforeSendCallback(enrichedMetric) : enrichedMetric;
+
+  if (!processedMetric) {
+    DEBUG_BUILD && debug.log('`beforeSendMetric` returned `null`, will not send metric.');
+    return;
+  }
+
+  const serializedMetric = _buildSerializedMetric(processedMetric, client, currentScope);
 
   DEBUG_BUILD && debug.log('[Metric]', serializedMetric);
 
   captureSerializedMetric(client, serializedMetric);
 
-  client.emit('afterCaptureMetric', metric);
+  client.emit('afterCaptureMetric', enrichedMetric);
 }
 
 /**

packages/core/src/types-hoist/options.ts

@@ -287,6 +287,7 @@ export interface ClientOptions<TO extends BaseTransportOptions = BaseTransportOp
      *
      * @default false
      * @experimental
+     * @deprecated Use the top level`enableMetrics` option instead.
      */
     enableMetrics?: boolean;
 
@@ -302,6 +303,7 @@ export interface ClientOptions<TO extends BaseTransportOptions = BaseTransportOp
      *
      * @param metric The metric generated by the SDK.
      * @returns A new metric that will be sent | null.
+     * @deprecated Use the top level`beforeSendMetric` option instead.
      */
     beforeSendMetric?: (metric: Metric) => Metric | null;
   };
@@ -401,6 +403,27 @@ export interface ClientOptions<TO extends BaseTransportOptions = BaseTransportOp
    */
   beforeSendLog?: (log: Log) => Log | null;
 
+  /**
+   * If metrics support should be enabled.
+   *
+   * @default true
+   */
+  enableMetrics?: boolean;
+
+  /**
+   * An event-processing callback for metrics, guaranteed to be invoked after all other metric
+   * processors. This allows a metric to be modified or dropped before it's sent.
+   *
+   * Note that you must return a valid metric from this callback. If you do not wish to modify the metric, simply return
+   * it at the end. Returning `null` will cause the metric to be dropped.
+   *
+   * @default undefined
+   *
+   * @param metric The metric generated by the SDK.
+   * @returns A new metric that will be sent.
+   */
+  beforeSendMetric?: (metric: Metric) => Metric;
+
   /**
    * Function to compute tracing sample rate dynamically and filter unwanted traces.
    *

packages/core/test/lib/client.test.ts

@@ -2753,7 +2753,6 @@ describe('Client', () => {
     it('flushes metrics when weight exceeds 800KB', () => {
       const options = getDefaultTestClientOptions({
         dsn: PUBLIC_DSN,
-        _experiments: { enableMetrics: true },
       });
       const client = new TestClient(options);
       const scope = new Scope();
@@ -2774,7 +2773,6 @@ describe('Client', () => {
     it('accumulates metric weight without flushing when under threshold', () => {
       const options = getDefaultTestClientOptions({
         dsn: PUBLIC_DSN,
-        _experiments: { enableMetrics: true },
       });
       const client = new TestClient(options);
       const scope = new Scope();
@@ -2791,7 +2789,6 @@ describe('Client', () => {
     it('flushes metrics on flush event', () => {
       const options = getDefaultTestClientOptions({
         dsn: PUBLIC_DSN,
-        _experiments: { enableMetrics: true },
       });
       const client = new TestClient(options);
       const scope = new Scope();