Don't load onSnapshot from cache in hook listen for contract (could h…

…elp 404 errors?)

web/lib/firebase/contracts.ts

@@ -17,7 +17,7 @@ import {
 import _ from 'lodash'
 
 import { app } from './init'
-import { getValues, listenForValues } from './utils'
+import { getValues, listenForValue, listenForValues } from './utils'
 import { Contract } from '../../../common/contract'
 import { getProbability } from '../../../common/calculate'
 import { createRNG, shuffle } from '../../../common/util/random'
@@ -125,9 +125,7 @@ export function listenForContract(
   setContract: (contract: Contract | null) => void
 ) {
   const contractRef = doc(contractCollection, contractId)
-  return onSnapshot(contractRef, (contractSnap) => {
-    setContract((contractSnap.data() ?? null) as Contract | null)
-  })
+  return listenForValue<Contract>(contractRef, setContract)
 }
 
 function chooseRandomSubset(contracts: Contract[], count: number) {

web/lib/firebase/utils.ts

@@ -23,6 +23,8 @@ export function listenForValue<T>(
   setValue: (value: T | null) => void
 ) {
   return onSnapshot(docRef, (snapshot) => {
+    if (snapshot.metadata.fromCache) return
+
     const value = snapshot.exists() ? (snapshot.data() as T) : null
     setValue(value)
   })