template-app/modules/account/__tests__/harness.ts

// The app wired the way apps/web and apps/worker wire the account module -- the registry from the
// manifests, a memory data source, the tenancy hooks, the account ports and the opt-in modules'
// recording platforms -- plus `flaky`, a module whose share of an account can be made to fail, so
// the partial-failure and resume paths are proven whichever opt-in modules this app kept.

import { createHash } from "node:crypto"
import { sessions } from "@conusai-kit/auth"
import {
  type Actor,
  AppError,
  buildRegistry,
  Container,
  contribute,
  createCaller,
  defineModule,
  type ModuleManifest,
  type Registry,
  type TransportCaller,
} from "@conusai-kit/core"
import { createMemoryDataSource, DATA_SOURCE, entitiesOf, SYSTEM_DATA, toInstant } from "@conusai-kit/data"
import { GUIDES_PLATFORM, GUIDES_REGISTRY } from "@conusai-kit/guides" // kit:guides
import { recordingGuidesPlatform } from "@conusai-kit/guides/testing" // kit:guides
import { SUPPORT_PLATFORM } from "@conusai-kit/support" // kit:support
import { recordingSupportPlatform } from "@conusai-kit/support/testing" // kit:support
import { accountData, createTenancyHooks, requireAppUser, TENANCY } from "@conusai-kit/tenancy"
import { appModules } from "../../index.js"
import {
  ACCOUNT_CREDENTIAL,
  ACCOUNT_IDENTITY_PROVIDER,
  ACCOUNT_PRIVACY,
  ACCOUNT_REGISTRY,
  type AccountCredential,
  type AccountIdentityProvider,
  type AccountPrivacy,
} from "../index.js"

export const ISSUER = "https://id.example.test"

/** A stand-in for the hash of a person's session handle, distinct per person as the real one is. */
export const handleHashOf = (email: string): string => createHash("sha256").update(email).digest("hex")

/**
 * The app's modules without `removed`, as `kit template:prune --without` leaves them: the module, and
 * every other module's contribution to an extension point the removed module declared.
 */
export function modulesWithout(...removed: string[]): ModuleManifest[] {
  return appModules
    .filter((module) => !removed.includes(module.id))
    .map((module) => ({
      ...module,
      extends: (module.extends ?? []).filter(
        (contribution) => !removed.includes(contribution.point.id.split(".")[0] ?? ""),
      ),
    }))
}

/** What `flaky` does when asked, and what it saw. */
export interface FlakyState {
  exportFails: boolean
  eraseFails: boolean
  readonly exported: string[]
  readonly erased: string[]
  /** Called inside each erasure, before it answers: a test looks at the stored rows at that moment. */
  onErase?: (subject: string) => Promise<void>
}

const unavailable = () =>
  new AppError({ type: "/problems/flaky_unavailable", title: "Unavailable", status: 503, code: "flaky_unavailable" })

export function flakyModule(state: FlakyState): ModuleManifest {
  return defineModule({
    id: "flaky",
    version: "0.1.0",
    kit: "^0.1.0",
    requires: ["tenancy"],
    extends: [
      contribute(accountData, [
        {
          key: "flaky",
          async export({ subject }) {
            if (state.exportFails) throw unavailable()
            state.exported.push(subject)
            return { subject, items: 1 }
          },
          async erase({ subject }) {
            await state.onErase?.(subject)
            if (state.eraseFails) throw unavailable()
            state.erased.push(subject)
          },
        },
      ]),
    ],
  })
}

/**
 * The memory data source, with the session table's listing made to fail while `failing.sessions` is
 * set: the first step of a deletion (revoking the person's live sessions) then throws, as a database
 * outage would, after the ledger row was written.
 */
export function failingSessions(data: MemoryData): { data: MemoryData; failing: { sessions: boolean } } {
  const failing = { sessions: false }
  const outage = () => {
    throw new AppError({ type: "/problems/unavailable", title: "Unavailable", status: 503, code: "unavailable" })
  }
  const wrapped = new Proxy(data, {
    get(target, property, receiver) {
      const value = Reflect.get(target, property, receiver)
      if (property !== "global") return typeof value === "function" ? value.bind(target) : value
      return (entity: Parameters<MemoryData["global"]>[0]) => {
        const repository = target.global(entity)
        if ((entity as unknown) !== sessions) return repository
        return new Proxy(repository, {
          get(repo, name, r) {
            const method = Reflect.get(repo, name, r)
            if (typeof method !== "function") return method
            return (...args: unknown[]) => (failing.sessions && name === "list" ? outage() : method.apply(repo, args))
          },
        })
      }
    },
  })
  return { data: wrapped, failing }
}

export const newFlaky = (): FlakyState => ({ exportFails: false, eraseFails: false, exported: [], erased: [] })

export type MemoryData = ReturnType<typeof createMemoryDataSource>

export interface Person {
  readonly actor: Actor & { readonly userId: string }
  readonly email: string
  readonly subject: string
  readonly sessionId: string
  /** The person's caller, as the web binds it for a browser session (or the credential given). */
  call(credential?: AccountCredential): TransportCaller
}

export function makeApp(
  options: {
    modules?: readonly ModuleManifest[]
    data?: MemoryData
    /** Bound in the process container: every request and the worker's sweep have it. */
    identityProvider?: AccountIdentityProvider
    /** Bound in each request's container only: a sweep in this app runs without it. */
    requestIdentityProvider?: AccountIdentityProvider
    /** The platform's privacy service (ADR-049), bound in the process container. */
    privacy?: AccountPrivacy
  } = {},
) {
  const registry: Registry = buildRegistry([...(options.modules ?? appModules)])
  const data = options.data ?? createMemoryDataSource({ entities: entitiesOf(registry, "postgres") })
  const root = new Container()
  root.value(DATA_SOURCE, data)
  root.value(SYSTEM_DATA, data)
  root.value(ACCOUNT_REGISTRY, registry)
  if (options.identityProvider) root.value(ACCOUNT_IDENTITY_PROVIDER, options.identityProvider)
  if (options.privacy) root.value(ACCOUNT_PRIVACY, options.privacy)
  const guides = recordingGuidesPlatform() // kit:guides
  root.value(GUIDES_PLATFORM, guides) // kit:guides
  root.value(GUIDES_REGISTRY, registry) // kit:guides
  const support = recordingSupportPlatform() // kit:support
  root.value(SUPPORT_PLATFORM, support) // kit:support

  const callerFor = (actor: Actor, credential: AccountCredential): TransportCaller => {
    const tenancy = createTenancyHooks({ data, registry })
    const container = root.child()
    container.value(TENANCY, tenancy)
    container.value(ACCOUNT_CREDENTIAL, credential)
    if (options.requestIdentityProvider) container.value(ACCOUNT_IDENTITY_PROVIDER, options.requestIdentityProvider)
    return createCaller({ registry, container, tenancy }, { actor })
  }

  /** A first sign-in, as kit-auth's callback makes it: the user, the identity mapping, a session row. */
  const signUp = async (email: string): Promise<Person> => {
    const subject = `sub-${email}`
    const user = await requireAppUser(data, {
      issuer: ISSUER,
      subject,
      email,
      displayName: email.split("@")[0] ?? email,
      locale: "en",
    })
    const now = Date.now()
    const session = await data.global(sessions).insert({
      userId: user.id,
      issuer: ISSUER,
      subject,
      handleHash: handleHashOf(email),
      tokens: "sealed-tokens-of-the-test",
      accessTokenExpiresAt: toInstant(now + 3600_000),
      lastSeenAt: toInstant(now),
      absoluteExpiresAt: toInstant(now + 14 * 86400_000),
      revokedAt: null,
    })
    const actor = { userId: user.id }
    const browser: AccountCredential = { interactive: true, sessionId: session.id }
    return {
      actor,
      email,
      subject,
      sessionId: session.id,
      call: (credential = browser) => callerFor(actor, credential),
    }
  }

  /** The worker's run of the sweep job: a scopeless job, in a container with no credential. */
  const sweep = async (): Promise<void> => {
    const job = registry.jobs["account.deletion.sweep"]
    if (!job) throw new Error("the account module declares no sweep job")
    await job.def.handler(null, { container: root.child(), correlationId: "test-sweep", attempt: 1 })
  }

  return {
    registry,
    data,
    root,
    signUp,
    sweep,
    guides, // kit:guides
    support, // kit:support
  }
}