fix(web): the client half of a trace no longer disappears

apps/web/src/lib/runtime.test.ts

@@ -0,0 +1,18 @@
+import { describe, expect, it } from "@effect/vitest";
+import * as Effect from "effect/Effect";
+import * as Tracer from "effect/Tracer";
+
+import { ClientTracingLive } from "../observability/clientTracer";
+import { runtime } from "./runtime";
+
+const readTracer = Effect.service(Tracer.Tracer);
+
+describe("web runtime", () => {
+  it.effect("installs the client tracer so client spans reach the trace proxy", () =>
+    Effect.gen(function* () {
+      const installed = yield* Effect.promise(() => runtime.runPromise(readTracer));
+
+      expect(installed).toBe(yield* readTracer);
+    }).pipe(Effect.provide(ClientTracingLive)),
+  );
+});

apps/web/src/lib/runtime.ts

@@ -11,6 +11,7 @@ import { primaryEnvironmentHttpLayer } from "../environments/primary/httpLayer";
 import { browserCryptoLayer } from "../cloud/dpop";
 import { managedRelayClientLayer } from "../cloud/managedRelayLayer";
 import { resolveCloudPublicConfig, resolveRelayTracingConfig } from "../cloud/publicConfig";
+import { ClientTracingLive } from "../observability/clientTracer";
 
 function configuredRelayUrl(): string {
   return resolveCloudPublicConfig().relayUrl ?? "http://relay.invalid";
@@ -29,6 +30,7 @@ type RuntimeLayerSource =
   | typeof browserCryptoLayer
   | typeof Socket.layerWebSocketConstructorGlobal
   | typeof relayTracingLayer
+  | typeof ClientTracingLive
   | ReturnType<typeof managedRelayClientLayer>;
 
 export const remoteHttpRuntime = ManagedRuntime.make(httpClientLayer);
@@ -58,6 +60,7 @@ const runtimeLayer = Layer.mergeAll(
   httpClientLayer,
   browserCryptoLayer,
   Socket.layerWebSocketConstructorGlobal,
+  ClientTracingLive,
   relayTracingLayer,
   managedRelayClientLayer(configuredRelayUrl()).pipe(
     Layer.provide(Layer.mergeAll(httpClientLayer, browserCryptoLayer)),

apps/web/src/observability/clientTracer.ts

@@ -0,0 +1,29 @@
+import * as Layer from "effect/Layer";
+import * as Tracer from "effect/Tracer";
+
+let delegate: Tracer.Tracer | null = null;
+
+/**
+ * Points the installed tracer at the exporter `configureClientTracing` just built,
+ * or at nothing while no exporter is configured.
+ */
+export function setClientTracerDelegate(next: Tracer.Tracer | null): void {
+  delegate = next;
+}
+
+export function hasClientTracerDelegate(): boolean {
+  return delegate !== null;
+}
+
+/**
+ * Installed once when the client runtime is built, before any exporter exists, so
+ * client spans keep flowing to whatever exporter is configured later on.
+ */
+export const ClientTracingLive = Layer.succeed(
+  Tracer.Tracer,
+  Tracer.make({
+    span(options) {
+      return delegate?.span(options) ?? new Tracer.NativeSpan(options);
+    },
+  }),
+);

apps/web/src/observability/clientTracing.ts

@@ -2,13 +2,13 @@ import * as Exit from "effect/Exit";
 import * as Layer from "effect/Layer";
 import * as ManagedRuntime from "effect/ManagedRuntime";
 import * as Scope from "effect/Scope";
-import * as Tracer from "effect/Tracer";
 import { HttpClient } from "effect/unstable/http";
 import { OtlpExporter, OtlpSerialization, OtlpTracer } from "effect/unstable/observability";
 
 import { settleAsyncResult, squashAtomCommandFailure } from "@t3tools/client-runtime/state/runtime";
 import { safeErrorLogAttributes } from "@t3tools/client-runtime/errors";
 import { resolvePrimaryEnvironmentHttpUrl } from "../environments/primary";
+import { hasClientTracerDelegate, setClientTracerDelegate } from "./clientTracer";
 import { primaryEnvironmentHttpLayer } from "../environments/primary/httpLayer";
 import { isElectron } from "../env";
 import { APP_VERSION } from "~/branding";
@@ -30,7 +30,6 @@ const delegateRuntimeLayer = Layer.mergeAll(
   Layer.succeed(HttpClient.TracerDisabledWhen, () => true),
 );
 
-let activeDelegate: Tracer.Tracer | null = null;
 let activeRuntime: ManagedRuntime.ManagedRuntime<never, never> | null = null;
 let activeScope: Scope.Closeable | null = null;
 let activeConfigKey: string | null = null;
@@ -41,15 +40,6 @@ export interface ClientTracingConfig {
   readonly exportIntervalMs?: number;
 }
 
-export const ClientTracingLive = Layer.succeed(
-  Tracer.Tracer,
-  Tracer.make({
-    span(options) {
-      return activeDelegate?.span(options) ?? new Tracer.NativeSpan(options);
-    },
-  }),
-);
-
 export function configureClientTracing(config: ClientTracingConfig = {}): Promise<void> {
   if (config.exportIntervalMs === undefined && activeConfigKey !== null) {
     return pendingConfiguration;
@@ -63,7 +53,7 @@ async function applyClientTracingConfig(config: ClientTracingConfig): Promise<vo
   const exportIntervalMs = Math.max(10, config.exportIntervalMs ?? DEFAULT_EXPORT_INTERVAL_MS);
   const nextConfigKey = `${otlpTracesUrl}|${exportIntervalMs}`;
 
-  if (activeConfigKey === nextConfigKey && activeDelegate !== null) {
+  if (activeConfigKey === nextConfigKey && hasClientTracerDelegate()) {
     return;
   }
 
@@ -73,7 +63,7 @@ async function applyClientTracingConfig(config: ClientTracingConfig): Promise<vo
   const previousRuntime = activeRuntime;
   const previousScope = activeScope;
 
-  activeDelegate = null;
+  setClientTracerDelegate(null);
   activeRuntime = null;
   activeScope = null;
 
@@ -115,7 +105,7 @@ async function applyClientTracingConfig(config: ClientTracingConfig): Promise<vo
     return;
   }
 
-  activeDelegate = delegateResult.value;
+  setClientTracerDelegate(delegateResult.value);
   activeRuntime = runtime;
   activeScope = scope;
 }
@@ -135,7 +125,7 @@ async function disposeTracerRuntime(
 export async function __resetClientTracingForTests() {
   configurationGeneration++;
   activeConfigKey = null;
-  activeDelegate = null;
+  setClientTracerDelegate(null);
   pendingConfiguration = Promise.resolve();
 
   const runtime = activeRuntime;