feat(gateway): add harness registry and fake adapter

2026-08-11 19:22:27 -05:00
parent fb9f9cda5a
commit 43513c28f7
8 changed files with 1204 additions and 0 deletions
@@ -0,0 +1,100 @@
+import { Injectable } from '@nestjs/common';
+import type {
+  HarnessAdapter,
+  HarnessErrorCode,
+  HarnessErrorDto,
+  HarnessSelection,
+} from '@mosaicstack/types';
+
+/**
+ * A typed harness operation failure that carries a fully-formed, browser-safe
+ * {@link HarnessErrorDto}. The DTO's `selection` is always the exact requested
+ * tuple — there is no field through which a substituted "effective" selection
+ * could ever be reported.
+ */
+export class HarnessOperationError extends Error {
+  readonly code: HarnessErrorCode;
+  readonly dto: HarnessErrorDto;
+
+  constructor(dto: HarnessErrorDto) {
+    super(dto.message);
+    this.name = 'HarnessOperationError';
+    this.code = dto.code;
+    this.dto = dto;
+  }
+}
+
+/** Build a {@link HarnessOperationError} that echoes the requested selection unchanged. */
+export function operationError(
+  code: HarnessErrorCode,
+  message: string,
+  selection: HarnessSelection,
+  correlationId: string,
+  retryable = false,
+): HarnessOperationError {
+  return new HarnessOperationError({ code, message, retryable, correlationId, selection });
+}
+
+/** Raised when an unknown harness id is looked up. Discriminated by `code`. */
+export class HarnessAdapterUnavailableError extends Error {
+  readonly code = 'adapter_unavailable' as const satisfies HarnessErrorCode;
+
+  constructor(readonly harnessId: string) {
+    super(`No harness adapter is registered for id "${harnessId}".`);
+    this.name = 'HarnessAdapterUnavailableError';
+  }
+}
+
+export type HarnessRegistrationFailure = 'blank_id' | 'duplicate_id';
+
+/** Raised when an adapter cannot be registered (blank or duplicate id). */
+export class HarnessRegistrationError extends Error {
+  constructor(
+    readonly reason: HarnessRegistrationFailure,
+    readonly harnessId: string,
+  ) {
+    super(
+      reason === 'blank_id'
+        ? 'A harness adapter id must be a non-empty string.'
+        : `A harness adapter is already registered for id "${harnessId}".`,
+    );
+    this.name = 'HarnessRegistrationError';
+  }
+}
+
+/**
+ * Harness-neutral adapter registry. Adapters are keyed by their harness id.
+ * Registration rejects blank and duplicate ids; lookup of an unknown id fails
+ * with {@link HarnessAdapterUnavailableError} (`adapter_unavailable`).
+ */
+@Injectable()
+export class HarnessRegistry {
+  private readonly adapters = new Map<string, HarnessAdapter>();
+
+  register(adapter: HarnessAdapter): void {
+    const id = adapter.id;
+    if (typeof id !== 'string' || id.trim().length === 0) {
+      throw new HarnessRegistrationError('blank_id', id ?? '');
+    }
+    if (this.adapters.has(id)) {
+      throw new HarnessRegistrationError('duplicate_id', id);
+    }
+    this.adapters.set(id, adapter);
+  }
+
+  get(harnessId: string): HarnessAdapter {
+    const adapter = this.adapters.get(harnessId);
+    if (!adapter) {
+      throw new HarnessAdapterUnavailableError(harnessId);
+    }
+    return adapter;
+  }
+
+  has(harnessId: string): boolean {
+    return this.adapters.has(harnessId);
+  }
+
+  list(): readonly HarnessAdapter[] {
+    return [...this.adapters.values()];
+  }
+}