Migrate createAnswer function to v2 (#634)

* Migrate createAnswer function to v2

* Remove unhelpful toString on APIError

functions/src/create-answer.ts

@@ -1,5 +1,5 @@
-import * as functions from 'firebase-functions'
 import * as admin from 'firebase-admin'
+import { z } from 'zod'
 
 import { Contract } from '../../common/contract'
 import { User } from '../../common/user'
@@ -7,122 +7,103 @@ import { getNewMultiBetInfo } from '../../common/new-bet'
 import { Answer, MAX_ANSWER_LENGTH } from '../../common/answer'
 import { getContract, getValues } from './utils'
 import { sendNewAnswerEmail } from './emails'
+import { APIError, newEndpoint, validate } from './api'
 
-export const createAnswer = functions
-  .runWith({ minInstances: 1, secrets: ['MAILGUN_KEY'] })
-  .https.onCall(
-    async (
-      data: {
-        contractId: string
-        amount: number
-        text: string
-      },
-      context
-    ) => {
-      const userId = context?.auth?.uid
-      if (!userId) return { status: 'error', message: 'Not authorized' }
+const bodySchema = z.object({
+  contractId: z.string().max(MAX_ANSWER_LENGTH),
+  amount: z.number().gt(0),
+  text: z.string(),
+})
 
-      const { contractId, amount, text } = data
+const opts = { secrets: ['MAILGUN_KEY'] }
 
-      if (amount <= 0 || isNaN(amount) || !isFinite(amount))
-        return { status: 'error', message: 'Invalid amount' }
+export const createanswer = newEndpoint(opts, async (req, auth) => {
+  const { contractId, amount, text } = validate(bodySchema, req.body)
 
-      if (!text || typeof text !== 'string' || text.length > MAX_ANSWER_LENGTH)
-        return { status: 'error', message: 'Invalid text' }
+  if (!isFinite(amount)) throw new APIError(400, 'Invalid amount')
 
-      // Run as transaction to prevent race conditions.
-      const result = await firestore.runTransaction(async (transaction) => {
-        const userDoc = firestore.doc(`users/${userId}`)
-        const userSnap = await transaction.get(userDoc)
-        if (!userSnap.exists)
-          return { status: 'error', message: 'User not found' }
-        const user = userSnap.data() as User
+  // Run as transaction to prevent race conditions.
+  const answer = await firestore.runTransaction(async (transaction) => {
+    const userDoc = firestore.doc(`users/${auth.uid}`)
+    const userSnap = await transaction.get(userDoc)
+    if (!userSnap.exists) throw new APIError(400, 'User not found')
+    const user = userSnap.data() as User
 
-        if (user.balance < amount)
-          return { status: 'error', message: 'Insufficient balance' }
+    if (user.balance < amount) throw new APIError(400, 'Insufficient balance')
 
-        const contractDoc = firestore.doc(`contracts/${contractId}`)
-        const contractSnap = await transaction.get(contractDoc)
-        if (!contractSnap.exists)
-          return { status: 'error', message: 'Invalid contract' }
-        const contract = contractSnap.data() as Contract
+    const contractDoc = firestore.doc(`contracts/${contractId}`)
+    const contractSnap = await transaction.get(contractDoc)
+    if (!contractSnap.exists) throw new APIError(400, 'Invalid contract')
+    const contract = contractSnap.data() as Contract
 
-        if (contract.outcomeType !== 'FREE_RESPONSE')
-          return {
-            status: 'error',
-            message: 'Requires a free response contract',
-          }
+    if (contract.outcomeType !== 'FREE_RESPONSE')
+      throw new APIError(400, 'Requires a free response contract')
 
-        const { closeTime, volume } = contract
-        if (closeTime && Date.now() > closeTime)
-          return { status: 'error', message: 'Trading is closed' }
+    const { closeTime, volume } = contract
+    if (closeTime && Date.now() > closeTime)
+      throw new APIError(400, 'Trading is closed')
 
-        const [lastAnswer] = await getValues<Answer>(
-          firestore
-            .collection(`contracts/${contractId}/answers`)
-            .orderBy('number', 'desc')
-            .limit(1)
-        )
+    const [lastAnswer] = await getValues<Answer>(
+      firestore
+        .collection(`contracts/${contractId}/answers`)
+        .orderBy('number', 'desc')
+        .limit(1)
+    )
 
-        if (!lastAnswer)
-          return { status: 'error', message: 'Could not fetch last answer' }
+    if (!lastAnswer) throw new APIError(500, 'Could not fetch last answer')
 
-        const number = lastAnswer.number + 1
-        const id = `${number}`
+    const number = lastAnswer.number + 1
+    const id = `${number}`
 
-        const newAnswerDoc = firestore
-          .collection(`contracts/${contractId}/answers`)
-          .doc(id)
+    const newAnswerDoc = firestore
+      .collection(`contracts/${contractId}/answers`)
+      .doc(id)
 
-        const answerId = newAnswerDoc.id
-        const { username, name, avatarUrl } = user
+    const answerId = newAnswerDoc.id
+    const { username, name, avatarUrl } = user
 
-        const answer: Answer = {
-          id,
-          number,
-          contractId,
-          createdTime: Date.now(),
-          userId: user.id,
-          username,
-          name,
-          avatarUrl,
-          text,
-        }
-        transaction.create(newAnswerDoc, answer)
-
-        const loanAmount = 0
-
-        const { newBet, newPool, newTotalShares, newTotalBets } =
-          getNewMultiBetInfo(answerId, amount, contract, loanAmount)
-
-        const newBalance = user.balance - amount
-        const betDoc = firestore
-          .collection(`contracts/${contractId}/bets`)
-          .doc()
-        transaction.create(betDoc, {
-          id: betDoc.id,
-          userId: user.id,
-          ...newBet,
-        })
-        transaction.update(userDoc, { balance: newBalance })
-        transaction.update(contractDoc, {
-          pool: newPool,
-          totalShares: newTotalShares,
-          totalBets: newTotalBets,
-          answers: [...(contract.answers ?? []), answer],
-          volume: volume + amount,
-        })
-
-        return { status: 'success', answerId, betId: betDoc.id, answer }
-      })
-
-      const { answer } = result
-      const contract = await getContract(contractId)
-
-      if (answer && contract) await sendNewAnswerEmail(answer, contract)
-
-      return result
+    const answer: Answer = {
+      id,
+      number,
+      contractId,
+      createdTime: Date.now(),
+      userId: user.id,
+      username,
+      name,
+      avatarUrl,
+      text,
     }
-  )
+    transaction.create(newAnswerDoc, answer)
+
+    const loanAmount = 0
+
+    const { newBet, newPool, newTotalShares, newTotalBets } =
+      getNewMultiBetInfo(answerId, amount, contract, loanAmount)
+
+    const newBalance = user.balance - amount
+    const betDoc = firestore.collection(`contracts/${contractId}/bets`).doc()
+    transaction.create(betDoc, {
+      id: betDoc.id,
+      userId: user.id,
+      ...newBet,
+    })
+    transaction.update(userDoc, { balance: newBalance })
+    transaction.update(contractDoc, {
+      pool: newPool,
+      totalShares: newTotalShares,
+      totalBets: newTotalBets,
+      answers: [...(contract.answers ?? []), answer],
+      volume: volume + amount,
+    })
+
+    return answer
+  })
+
+  const contract = await getContract(contractId)
+
+  if (answer && contract) await sendNewAnswerEmail(answer, contract)
+
+  return answer
+})
 
 const firestore = admin.firestore()

functions/src/index.ts

@@ -6,7 +6,6 @@ admin.initializeApp()
 export * from './transact'
 export * from './stripe'
 export * from './create-user'
-export * from './create-answer'
 export * from './on-create-bet'
 export * from './on-create-comment-on-contract'
 export * from './on-view'
@@ -30,6 +29,7 @@ export * from './on-create-txn'
 // v2
 export * from './health'
 export * from './change-user-info'
+export * from './create-answer'
 export * from './place-bet'
 export * from './sell-bet'
 export * from './sell-shares'

web/components/answers/create-answer-panel.tsx

@@ -6,7 +6,7 @@ import { findBestMatch } from 'string-similarity'
 import { FreeResponseContract } from 'common/contract'
 import { BuyAmountInput } from '../amount-input'
 import { Col } from '../layout/col'
-import { createAnswer } from 'web/lib/firebase/fn-call'
+import { APIError, createAnswer } from 'web/lib/firebase/api-call'
 import { Row } from '../layout/row'
 import {
   formatMoney,
@@ -46,20 +46,23 @@ export function CreateAnswerPanel(props: { contract: FreeResponseContract }) {
     if (canSubmit) {
       setIsSubmitting(true)
 
-      const result = await createAnswer({
-        contractId: contract.id,
-        text,
-        amount: betAmount,
-      }).then((r) => r.data)
-
-      setIsSubmitting(false)
-
-      if (result.status === 'success') {
+      try {
+        await createAnswer({
+          contractId: contract.id,
+          text,
+          amount: betAmount,
+        })
         setText('')
         setBetAmount(10)
         setAmountError(undefined)
         setPossibleDuplicateAnswer(undefined)
-      } else setAmountError(result.message)
+      } catch (e) {
+        if (e instanceof APIError) {
+          setAmountError(e.toString())
+        }
+      }
+
+      setIsSubmitting(false)
     }
   }
 

web/lib/firebase/api-call.ts

@@ -10,9 +10,6 @@ export class APIError extends Error {
     this.name = 'APIError'
     this.details = details
   }
-  toString() {
-    return this.name
-  }
 }
 
 export async function call(url: string, method: string, params: any) {
@@ -53,6 +50,9 @@ export function getFunctionUrl(name: string) {
   }
 }
 
+export function createAnswer(params: any) {
+  return call(getFunctionUrl('createanswer'), 'POST', params)
+}
 export function changeUserInfo(params: any) {
   return call(getFunctionUrl('changeuserinfo'), 'POST', params)
 }

web/lib/firebase/fn-call.ts

@@ -14,16 +14,6 @@ export const transact = cloudFunction<
   { status: 'error' | 'success'; message?: string; txn?: Txn }
 >('transact')
 
-export const createAnswer = cloudFunction<
-  { contractId: string; text: string; amount: number },
-  {
-    status: 'error' | 'success'
-    message?: string
-    answerId?: string
-    betId?: string
-  }
->('createAnswer')
-
 export const createUser: () => Promise<User | null> = () => {
   const local = safeLocalStorage()
   let deviceToken = local?.getItem('device-token')