Add fake payments API

README.md

@@ -4,3 +4,17 @@ This is a template project with best-practice modules:
 - Winterspec for defining the API
 - bun testing
 - Zustand store with zod definition for database state
+
+## Fake payments API
+
+The payments API stores fake payment records in memory and supports a small
+payment lifecycle:
+
+- `POST /payments/send` creates a pending payment. Reusing an
+  `idempotency_key` returns the existing payment instead of creating a
+  duplicate.
+- `GET /payments/list` returns payments and can filter by `recipient`,
+  `repository`, or `status`.
+- `GET /payments/get?payment_id=0` returns a payment by id.
+- `POST /payments/update-status` moves a pending payment to `completed`,
+  `canceled`, or `failed`. Terminal payments cannot be changed again.

lib/db/db-client.ts

@@ -1,9 +1,15 @@
-import { createStore, type StoreApi } from "zustand/vanilla"
+import { type HoistedStoreApi, hoist } from "zustand-hoist"
 import { immer } from "zustand/middleware/immer"
-import { hoist, type HoistedStoreApi } from "zustand-hoist"
+import { type StoreApi, createStore } from "zustand/vanilla"
 
-import { databaseSchema, type DatabaseSchema, type Thing } from "./schema.ts"
 import { combine } from "zustand/middleware"
+import {
+  type DatabaseSchema,
+  type Payment,
+  type PaymentStatus,
+  type Thing,
+  databaseSchema,
+} from "./schema.ts"
 
 export const createDatabase = () => {
   return hoist(createStore(initializer))
@@ -21,4 +27,75 @@ const initializer = combine(databaseSchema.parse({}), (set) => ({
       idCounter: state.idCounter + 1,
     }))
   },
+  sendPayment: (
+    payment: Omit<
+      Payment,
+      "payment_id" | "status" | "created_at" | "updated_at"
+    >,
+  ) => {
+    const now = new Date().toISOString()
+    let nextPayment: Payment | undefined
+
+    set((state) => {
+      if (payment.idempotency_key) {
+        const existing = state.payments.find(
+          (storedPayment) =>
+            storedPayment.idempotency_key === payment.idempotency_key,
+        )
+
+        if (existing) {
+          nextPayment = existing
+          return {}
+        }
+      }
+
+      nextPayment = {
+        ...payment,
+        payment_id: state.paymentIdCounter.toString(),
+        status: "pending",
+        created_at: now,
+        updated_at: now,
+      }
+
+      return {
+        payments: [...state.payments, nextPayment],
+        paymentIdCounter: state.paymentIdCounter + 1,
+      }
+    })
+
+    return nextPayment!
+  },
+  updatePaymentStatus: (
+    paymentId: string,
+    status: Exclude<PaymentStatus, "pending">,
+  ) => {
+    const now = new Date().toISOString()
+    let updatedPayment: Payment | undefined
+
+    set((state) => {
+      const payment = state.payments.find(
+        (storedPayment) => storedPayment.payment_id === paymentId,
+      )
+
+      if (!payment || payment.status !== "pending") {
+        return {}
+      }
+
+      updatedPayment = {
+        ...payment,
+        status,
+        updated_at: now,
+      }
+
+      return {
+        payments: state.payments.map((storedPayment) =>
+          storedPayment.payment_id === paymentId
+            ? updatedPayment!
+            : storedPayment,
+        ),
+      }
+    })
+
+    return updatedPayment
+  },
 }))

lib/db/schema.ts

@@ -9,8 +9,32 @@ export const thingSchema = z.object({
 })
 export type Thing = z.infer<typeof thingSchema>
 
+export const paymentStatusSchema = z.enum([
+  "pending",
+  "completed",
+  "canceled",
+  "failed",
+])
+export type PaymentStatus = z.infer<typeof paymentStatusSchema>
+
+export const paymentSchema = z.object({
+  payment_id: z.string(),
+  recipient: z.string(),
+  amount: z.number(),
+  currency: z.string(),
+  bounty_issue: z.number().optional(),
+  repository: z.string().optional(),
+  idempotency_key: z.string().optional(),
+  status: paymentStatusSchema,
+  created_at: z.string(),
+  updated_at: z.string(),
+})
+export type Payment = z.infer<typeof paymentSchema>
+
 export const databaseSchema = z.object({
   idCounter: z.number().default(0),
+  paymentIdCounter: z.number().default(0),
   things: z.array(thingSchema).default([]),
+  payments: z.array(paymentSchema).default([]),
 })
 export type DatabaseSchema = z.infer<typeof databaseSchema>

routes/payments/get.ts

@@ -0,0 +1,21 @@
+import { paymentSchema } from "lib/db/schema"
+import { withRouteSpec } from "lib/middleware/with-winter-spec"
+import { z } from "zod"
+
+export default withRouteSpec({
+  methods: ["GET"],
+  queryParams: z.object({
+    payment_id: z.string().min(1),
+  }),
+  jsonResponse: z.object({
+    payment: paymentSchema.optional(),
+  }),
+})((req, ctx) => {
+  const url = new URL(req.url)
+  const paymentId = url.searchParams.get("payment_id")
+  const payment = ctx.db.payments.find(
+    (storedPayment) => storedPayment.payment_id === paymentId,
+  )
+
+  return ctx.json({ payment })
+})

routes/payments/list.ts

@@ -0,0 +1,29 @@
+import { paymentSchema, paymentStatusSchema } from "lib/db/schema"
+import { withRouteSpec } from "lib/middleware/with-winter-spec"
+import { z } from "zod"
+
+export default withRouteSpec({
+  methods: ["GET"],
+  jsonResponse: z.object({
+    payments: z.array(paymentSchema),
+  }),
+})((req, ctx) => {
+  const url = new URL(req.url)
+  const recipient = url.searchParams.get("recipient")
+  const repository = url.searchParams.get("repository")
+  const statusParam = url.searchParams.get("status")
+  const status = statusParam
+    ? paymentStatusSchema.safeParse(statusParam)
+    : undefined
+
+  const payments = ctx.db.payments.filter((payment) => {
+    if (recipient && payment.recipient !== recipient) return false
+    if (repository && payment.repository !== repository) return false
+    if (status && (!status.success || payment.status !== status.data)) {
+      return false
+    }
+    return true
+  })
+
+  return ctx.json({ payments })
+})

routes/payments/send.ts

@@ -0,0 +1,25 @@
+import { paymentSchema } from "lib/db/schema"
+import { withRouteSpec } from "lib/middleware/with-winter-spec"
+import { z } from "zod"
+
+const sendPaymentRequestSchema = z.object({
+  recipient: z.string().min(1),
+  amount: z.number().positive(),
+  currency: z.string().min(1).default("USD"),
+  bounty_issue: z.number().int().positive().optional(),
+  repository: z.string().min(1).optional(),
+  idempotency_key: z.string().min(1).optional(),
+})
+
+export default withRouteSpec({
+  methods: ["POST"],
+  jsonBody: sendPaymentRequestSchema,
+  jsonResponse: z.object({
+    payment: paymentSchema,
+  }),
+})(async (req, ctx) => {
+  const body = sendPaymentRequestSchema.parse(await req.json())
+  const payment = ctx.db.sendPayment(body)
+
+  return ctx.json({ payment })
+})

routes/payments/update-status.ts

@@ -0,0 +1,23 @@
+import { paymentSchema } from "lib/db/schema"
+import { withRouteSpec } from "lib/middleware/with-winter-spec"
+import { z } from "zod"
+
+const updateStatusRequestSchema = z.object({
+  payment_id: z.string().min(1),
+  status: z.enum(["completed", "canceled", "failed"]),
+})
+
+export default withRouteSpec({
+  methods: ["POST"],
+  jsonBody: updateStatusRequestSchema,
+  jsonResponse: z.object({
+    payment: paymentSchema.optional(),
+  }),
+})(async (req, ctx) => {
+  const { payment_id, status } = updateStatusRequestSchema.parse(
+    await req.json(),
+  )
+  const payment = ctx.db.updatePaymentStatus(payment_id, status)
+
+  return ctx.json({ payment })
+})

tests/routes/payments.test.ts

@@ -0,0 +1,78 @@
+import { expect, test } from "bun:test"
+import { getTestServer } from "tests/fixtures/get-test-server"
+
+test("send, list, get, and complete a payment", async () => {
+  const { axios } = await getTestServer()
+
+  const sendResponse = await axios.post("/payments/send", {
+    recipient: "surim0n",
+    amount: 10,
+    currency: "USD",
+    bounty_issue: 1,
+    repository: "tscircuit/fake-algora",
+    idempotency_key: "issue-1-payment",
+  })
+
+  expect(sendResponse.data.payment).toMatchObject({
+    payment_id: "0",
+    recipient: "surim0n",
+    amount: 10,
+    currency: "USD",
+    bounty_issue: 1,
+    repository: "tscircuit/fake-algora",
+    idempotency_key: "issue-1-payment",
+    status: "pending",
+  })
+
+  const duplicateResponse = await axios.post("/payments/send", {
+    recipient: "surim0n",
+    amount: 10,
+    currency: "USD",
+    idempotency_key: "issue-1-payment",
+  })
+
+  expect(duplicateResponse.data.payment.payment_id).toBe("0")
+
+  const listResponse = await axios.get(
+    "/payments/list?recipient=surim0n&status=pending",
+  )
+
+  expect(listResponse.data.payments).toHaveLength(1)
+
+  const getResponse = await axios.get("/payments/get?payment_id=0")
+
+  expect(getResponse.data.payment.recipient).toBe("surim0n")
+
+  const completeResponse = await axios.post("/payments/update-status", {
+    payment_id: "0",
+    status: "completed",
+  })
+
+  expect(completeResponse.data.payment.status).toBe("completed")
+})
+
+test("completed payments cannot be moved into another terminal status", async () => {
+  const { axios } = await getTestServer()
+
+  await axios.post("/payments/send", {
+    recipient: "maintainer",
+    amount: 25,
+  })
+
+  await axios.post("/payments/update-status", {
+    payment_id: "0",
+    status: "completed",
+  })
+
+  const cancelResponse = await axios.post("/payments/update-status", {
+    payment_id: "0",
+    status: "canceled",
+  })
+
+  expect(cancelResponse.data.payment).toBeUndefined()
+
+  const listResponse = await axios.get("/payments/list?status=completed")
+
+  expect(listResponse.data.payments).toHaveLength(1)
+  expect(listResponse.data.payments[0].status).toBe("completed")
+})