Create free answer contract

common/antes.ts

@@ -61,3 +61,28 @@ export function getAnteBets(
 
   return { yesBet, noBet }
 }
+
+export function getFreeAnswerAnte(
+  creator: User,
+  contract: Contract<'MULTI'>,
+  anteBetId: string
+) {
+  const ante = contract.totalBets.YES + contract.totalBets.NO
+
+  const { createdTime } = contract
+
+  const anteBet: Bet<'MULTI'> = {
+    id: anteBetId,
+    userId: creator.id,
+    contractId: contract.id,
+    amount: ante,
+    shares: 0,
+    outcome: 'NONE',
+    probBefore: 0,
+    probAfter: 0,
+    createdTime,
+    isAnte: true,
+  }
+
+  return anteBet
+}

common/bet.ts

@@ -1,10 +1,13 @@
-export type Bet = {
+export type Bet<outcomeType extends 'BINARY' | 'MULTI' = 'BINARY'> = {
   id: string
   userId: string
   contractId: string
 
   amount: number // bet size; negative if SELL bet
-  outcome: 'YES' | 'NO'
+  outcome: {
+    BINARY: 'YES' | 'NO'
+    MULTI: string
+  }[outcomeType]
   shares: number // dynamic parimutuel pool weight; negative if SELL bet
 
   probBefore: number

common/contract.ts

@@ -11,13 +11,18 @@ export type Contract<outcomeType extends 'BINARY' | 'MULTI' = 'BINARY'> = {
   description: string // More info about what the contract is about
   tags: string[]
   lowercaseTags: string[]
-  outcomeType: outcomeType
   visibility: 'public' | 'unlisted'
 
+  outcomeType: outcomeType
+  outcomes: {
+    BINARY: undefined
+    MULTI: 'FREE_ANSWER' | string[]
+  }[outcomeType]
+
   mechanism: 'dpm-2'
   phantomShares: {
     BINARY: { YES: number; NO: number }
-    MULTI: { [answerId: string]: number }
+    MULTI: undefined
   }[outcomeType]
   pool: {
     BINARY: { YES: number; NO: number }

common/new-contract.ts

@@ -1,32 +1,37 @@
 import { calcStartPool } from './antes'
-
 import { Contract } from './contract'
 import { User } from './user'
 import { parseTags } from './util/parse'
+import { removeUndefinedProps } from './util/object'
 
 export function getNewContract(
   id: string,
   slug: string,
   creator: User,
   question: string,
+  outcomeType: 'BINARY' | 'MULTI',
   description: string,
   initialProb: number,
   ante: number,
   closeTime: number,
   extraTags: string[]
 ) {
-  const { sharesYes, sharesNo, poolYes, poolNo, phantomYes, phantomNo } =
-    calcStartPool(initialProb, ante)
-
   const tags = parseTags(
     `${question} ${description} ${extraTags.map((tag) => `#${tag}`).join(' ')}`
   )
   const lowercaseTags = tags.map((tag) => tag.toLowerCase())
 
-  const contract: Contract = {
+  const propsByOutcomeType =
+    outcomeType === 'BINARY'
+      ? getBinaryProps(initialProb, ante)
+      : getFreeAnswerProps()
+
+  const contract: Contract<'BINARY' | 'MULTI'> = removeUndefinedProps({
     id,
     slug,
-    outcomeType: 'BINARY',
+    mechanism: 'dpm-2',
+    outcomeType,
+    ...propsByOutcomeType,
 
     creatorId: creator.id,
     creatorName: creator.name,
@@ -38,22 +43,45 @@ export function getNewContract(
     tags,
     lowercaseTags,
     visibility: 'public',
+    isResolved: false,
+    createdTime: Date.now(),
+    lastUpdatedTime: Date.now(),
+    closeTime,
 
-    mechanism: 'dpm-2',
+    volume24Hours: 0,
+    volume7Days: 0,
+  })
+
+  return contract
+}
+
+const getBinaryProps = (initialProb: number, ante: number) => {
+  const { sharesYes, sharesNo, poolYes, poolNo, phantomYes, phantomNo } =
+    calcStartPool(initialProb, ante)
+
+  return {
     phantomShares: { YES: phantomYes, NO: phantomNo },
     pool: { YES: poolYes, NO: poolNo },
     totalShares: { YES: sharesYes, NO: sharesNo },
     totalBets: { YES: poolYes, NO: poolNo },
-    isResolved: false,
-
-    createdTime: Date.now(),
-    lastUpdatedTime: Date.now(),
-
-    volume24Hours: 0,
-    volume7Days: 0,
+    outcomes: undefined,
   }
-
-  if (closeTime) contract.closeTime = closeTime
-
-  return contract
+}
+
+const getFreeAnswerProps = () => {
+  return {
+    pool: {},
+    totalShares: {},
+    totalBets: {},
+    phantomShares: undefined,
+    outcomes: 'FREE_ANSWER' as const,
+  }
+}
+
+const getMultiProps = (
+  outcomes: string[],
+  initialProbs: number[],
+  ante: number
+) => {
+  // Not implemented.
 }

common/util/object.ts

@@ -0,0 +1,9 @@
+export const removeUndefinedProps = <T>(obj: T): T => {
+  let newObj: any = {}
+
+  for (let key of Object.keys(obj)) {
+    if ((obj as any)[key] !== undefined) newObj[key] = (obj as any)[key]
+  }
+
+  return newObj
+}

functions/src/change-user-info.ts

@@ -1,11 +1,12 @@
 import * as functions from 'firebase-functions'
 import * as admin from 'firebase-admin'
 
-import { getUser, removeUndefinedProps } from './utils'
+import { getUser } from './utils'
 import { Contract } from '../../common/contract'
 import { Comment } from '../../common/comment'
 import { User } from '../../common/user'
 import { cleanUsername } from '../../common/util/clean-username'
+import { removeUndefinedProps } from '../../common/util/object'
 
 export const changeUserInfo = functions
   .runWith({ minInstances: 1 })

functions/src/create-contract.ts

@@ -6,7 +6,11 @@ import { Contract } from '../../common/contract'
 import { slugify } from '../../common/util/slugify'
 import { randomString } from '../../common/util/random'
 import { getNewContract } from '../../common/new-contract'
-import { getAnteBets, MINIMUM_ANTE } from '../../common/antes'
+import {
+  getAnteBets,
+  getFreeAnswerAnte,
+  MINIMUM_ANTE,
+} from '../../common/antes'
 
 export const createContract = functions
   .runWith({ minInstances: 1 })
@@ -14,6 +18,7 @@ export const createContract = functions
     async (
       data: {
         question: string
+        outcomeType: 'BINARY' | 'MULTI'
         description: string
         initialProb: number
         ante: number
@@ -28,12 +33,26 @@ export const createContract = functions
       const creator = await getUser(userId)
       if (!creator) return { status: 'error', message: 'User not found' }
 
-      const { question, description, initialProb, ante, closeTime, tags } = data
+      const {
+        question,
+        outcomeType,
+        description,
+        initialProb,
+        ante,
+        closeTime,
+        tags,
+      } = data
 
-      if (!question || !initialProb)
-        return { status: 'error', message: 'Missing contract attributes' }
+      if (!question)
+        return { status: 'error', message: 'Missing question field' }
 
-      if (initialProb < 1 || initialProb > 99)
+      if (outcomeType !== 'BINARY' && outcomeType !== 'MULTI')
+        return { status: 'error', message: 'Invalid outcomeType' }
+
+      if (
+        outcomeType === 'BINARY' &&
+        (!initialProb || initialProb < 1 || initialProb > 99)
+      )
         return { status: 'error', message: 'Invalid initial probability' }
 
       if (
@@ -63,6 +82,7 @@ export const createContract = functions
         slug,
         creator,
         question,
+        outcomeType,
         description,
         initialProb,
         ante,
@@ -75,22 +95,35 @@ export const createContract = functions
       await contractRef.create(contract)
 
       if (ante) {
-        const yesBetDoc = firestore
-          .collection(`contracts/${contract.id}/bets`)
-          .doc()
+        if (outcomeType === 'BINARY') {
+          const yesBetDoc = firestore
+            .collection(`contracts/${contract.id}/bets`)
+            .doc()
 
-        const noBetDoc = firestore
-          .collection(`contracts/${contract.id}/bets`)
-          .doc()
+          const noBetDoc = firestore
+            .collection(`contracts/${contract.id}/bets`)
+            .doc()
 
-        const { yesBet, noBet } = getAnteBets(
-          creator,
-          contract,
-          yesBetDoc.id,
-          noBetDoc.id
-        )
-        await yesBetDoc.set(yesBet)
-        await noBetDoc.set(noBet)
+          const { yesBet, noBet } = getAnteBets(
+            creator,
+            contract as Contract<'BINARY'>,
+            yesBetDoc.id,
+            noBetDoc.id
+          )
+          await yesBetDoc.set(yesBet)
+          await noBetDoc.set(noBet)
+        } else if (outcomeType === 'MULTI') {
+          const anteBetDoc = firestore
+            .collection(`contracts/${contract.id}/bets`)
+            .doc()
+          getFreeAnswerAnte(
+            creator,
+            contract as Contract<'MULTI'>,
+            anteBetDoc.id
+          )
+          // Disable until we figure out how this should work.
+          // await anteBetDoc.set(anteBetDoc)
+        }
       }
 
       return { status: 'success', contract }

functions/src/utils.ts

@@ -77,13 +77,3 @@ export const chargeUser = (userId: string, charge: number) => {
 
   return updateUserBalance(userId, -charge)
 }
-
-export const removeUndefinedProps = <T>(obj: T): T => {
-  let newObj: any = {}
-
-  for (let key of Object.keys(obj)) {
-    if ((obj as any)[key] !== undefined) newObj[key] = (obj as any)[key]
-  }
-
-  return newObj
-}

web/pages/create.tsx

@@ -17,6 +17,7 @@ import { Title } from '../components/title'
 import { ProbabilitySelector } from '../components/probability-selector'
 import { parseWordsAsTags } from '../../common/util/parse'
 import { TagsList } from '../components/tags-list'
+import { Row } from '../components/layout/row'
 
 export default function Create() {
   const [question, setQuestion] = useState('')
@@ -61,6 +62,7 @@ export function NewContract(props: { question: string; tag?: string }) {
     createContract({}).catch() // warm up function
   }, [])
 
+  const [outcomeType, setOutcomeType] = useState<'BINARY' | 'MULTI'>('BINARY')
   const [initialProb, setInitialProb] = useState(50)
   const [description, setDescription] = useState('')
   const [tagText, setTagText] = useState<string>(tag ?? '')
@@ -105,6 +107,7 @@ export function NewContract(props: { question: string; tag?: string }) {
 
     const result: any = await createContract({
       question,
+      outcomeType,
       description,
       initialProb,
       ante,
@@ -126,18 +129,48 @@ export function NewContract(props: { question: string; tag?: string }) {
 
   return (
     <div>
-      <Spacer h={4} />
-
-      <div className="form-control">
-        <label className="label">
-          <span className="mb-1">Initial probability</span>
+      <label className="label">
+        <span className="mb-1">Answer type</span>
+      </label>
+      <Row className="form-control gap-2">
+        <label className="cursor-pointer label gap-2">
+          <input
+            className="radio"
+            type="radio"
+            name="opt"
+            checked={outcomeType === 'BINARY'}
+            value="BINARY"
+            onChange={(e) => setOutcomeType(e.target.value as 'BINARY')}
+          />
+          <span className="label-text">Yes / No</span>
         </label>
 
-        <ProbabilitySelector
-          probabilityInt={initialProb}
-          setProbabilityInt={setInitialProb}
-        />
-      </div>
+        <label className="cursor-pointer label gap-2">
+          <input
+            className="radio"
+            type="radio"
+            name="opt"
+            checked={outcomeType === 'MULTI'}
+            value="MULTI"
+            onChange={(e) => setOutcomeType(e.target.value as 'MULTI')}
+          />
+          <span className="label-text">Free response</span>
+        </label>
+      </Row>
+      <Spacer h={4} />
+
+      {outcomeType === 'BINARY' && (
+        <div className="form-control">
+          <label className="label">
+            <span className="mb-1">Initial probability</span>
+          </label>
+
+          <ProbabilitySelector
+            probabilityInt={initialProb}
+            setProbabilityInt={setInitialProb}
+          />
+        </div>
+      )}
 
       <Spacer h={4} />