refactor: consume Commonlib as a package

test/contracts/serviceContext.ts

@@ -0,0 +1,75 @@
+import type { ServiceContextContract } from "@vrtmrz/livesync-commonlib/context";
+import type { ServiceHub } from "@vrtmrz/livesync-commonlib/compat/services/ServiceHub";
+
+export const SERVICE_CONTEXT_MEMBERS = [
+    "API",
+    "path",
+    "database",
+    "databaseEvents",
+    "replicator",
+    "fileProcessing",
+    "replication",
+    "remote",
+    "conflict",
+    "appLifecycle",
+    "setting",
+    "tweakValue",
+    "vault",
+    "test",
+    "UI",
+    "config",
+    "keyValueDB",
+    "control",
+] as const satisfies readonly Exclude<keyof ServiceHub, "context">[];
+
+export type ServiceContextMember = (typeof SERVICE_CONTEXT_MEMBERS)[number];
+type MissingServiceContextMember = Exclude<Exclude<keyof ServiceHub, "context">, ServiceContextMember>;
+const serviceContextMembersAreExhaustive: [MissingServiceContextMember] extends [never] ? true : never = true;
+void serviceContextMembersAreExhaustive;
+
+export type ServiceContextResult = {
+    translation: string;
+    receivedEvents: string[];
+};
+
+export type ServiceCompositionResult = {
+    hubUsesExpectedContext: boolean;
+    servicesUsingExpectedContext: Record<ServiceContextMember, boolean>;
+};
+
+/**
+ * Observe the host-neutral results promised by ServiceContextContract.
+ *
+ * The caller chooses the translation key because translated text is
+ * host-configured. Event delivery itself is shared behaviour.
+ */
+export function observeServiceContext(context: ServiceContextContract, translationKey: string): ServiceContextResult {
+    const receivedEvents: string[] = [];
+    const unsubscribe = context.events.onEvent("hello", (value) => receivedEvents.push(value));
+    try {
+        context.events.emitEvent("hello", "context-contract-event");
+    } finally {
+        unsubscribe();
+    }
+    return {
+        translation: context.translate(translationKey),
+        receivedEvents,
+    };
+}
+
+/**
+ * Inspect whether a Service Hub and all public services preserve one exact
+ * context object instead of silently constructing or substituting another.
+ */
+export function observeServiceComposition(
+    hub: { readonly context: ServiceContextContract },
+    expectedContext: ServiceContextContract
+): ServiceCompositionResult {
+    const members = hub as unknown as Record<ServiceContextMember, { readonly context: ServiceContextContract }>;
+    return {
+        hubUsesExpectedContext: hub.context === expectedContext,
+        servicesUsingExpectedContext: Object.fromEntries(
+            SERVICE_CONTEXT_MEMBERS.map((member) => [member, members[member].context === expectedContext])
+        ) as Record<ServiceContextMember, boolean>,
+    };
+}