PM-5223: include challenge winners in member rerates

What was broken
QA challenge winners could be missing from member profile history and rating updates when review-api had no challengeResult rows for those winners.

Root cause (if identifiable)
The completed-challenge rerate path only discovered Development participants from review-api challengeResult rows. Winner-only QA participants stored in challenge-api ChallengeWinner were never passed into the Development rerating replay, so their history and rating stats were not updated.

What was changed
Merged placement ChallengeWinner rows into the Development participant discovery and rating replay paths while preserving review-api rows when both sources exist. The placement rows now drive the existing placement-score fallback so winner-only members receive profile history, statistics, and max rating updates.

Any added/updated tests
Added unit coverage for rerating winner-only ChallengeWinner placements in the Development rating engine and for StatisticsService including challenge winners when review result rows are absent.

Author: jmgasper

src/ratings/developRatingEngine.js

@@ -31,6 +31,7 @@ const CHALLENGE_TRACK_NAME = 'DEVELOPMENT'
 const CHALLENGE_TYPE_NAMES = [TYPE_NAMES.CHALLENGE, TYPE_NAMES.CODE]
 const RERATE_ACTOR = 'rerate-member-stats'
 const COMPLETED_CHALLENGE_STATUS = 'COMPLETED'
+const CHALLENGE_WINNER_RATING_TYPES = ['PLACEMENT']
 
 function isBigIntValue (value) {
   return Object.prototype.toString.call(value) === '[object BigInt]'
@@ -351,9 +352,11 @@ function findHistorySeedIndexForChallenge (historyRows, challengeEntry) {
 }
 
 function normalizeScore (row) {
-  const finalScore = Number(row.finalScore)
-  if (Number.isFinite(finalScore)) {
-    return finalScore
+  if (row.finalScore !== null && row.finalScore !== undefined) {
+    const finalScore = Number(row.finalScore)
+    if (Number.isFinite(finalScore)) {
+      return finalScore
+    }
   }
 
   const placement = Number(row.placement)
@@ -391,6 +394,145 @@ function isParticipantEligibleForRating (row) {
   return false
 }
 
+/**
+ * Convert a member user id into the numeric shape stored on ChallengeWinner.
+ * @param {BigInt|string|number} userId member identifier
+ * @returns {number|string} numeric user id when safe, otherwise the string form
+ */
+function toChallengeWinnerUserId (userId) {
+  const numericUserId = Number(userId)
+  return Number.isSafeInteger(numericUserId) ? numericUserId : String(userId)
+}
+
+/**
+ * Convert one ChallengeWinner row into the challengeResult-like row consumed by
+ * the Development rating replay. Winner rows only provide placement, so the
+ * existing placement score fallback drives the rating calculation.
+ * @param {Object} row ChallengeWinner row
+ * @returns {Object|null} review-row-compatible participant data
+ */
+function toChallengeWinnerParticipantRow (row) {
+  if (!row || row.userId === null || row.userId === undefined || !row.challengeId) {
+    return null
+  }
+
+  return {
+    challengeId: String(row.challengeId),
+    userId: String(row.userId),
+    placement: row.placement,
+    passedReview: true,
+    validSubmission: true,
+    createdAt: row.createdAt
+  }
+}
+
+/**
+ * Build the duplicate key used when merging challengeResult and ChallengeWinner
+ * participant rows for the same member and challenge.
+ * @param {Object} row participant row
+ * @returns {string} duplicate key
+ */
+function buildParticipantRowKey (row) {
+  return `${String(row && row.challengeId)}::${String(row && row.userId)}`
+}
+
+/**
+ * Merge review-api participant rows with ChallengeWinner placement rows. Review
+ * rows are kept when both sources exist because they may carry final score and
+ * source rating fields that are more precise than placement-only winners.
+ * @param {Array<Object>} reviewRows challengeResult rows
+ * @param {Array<Object>} winnerRows ChallengeWinner rows
+ * @returns {Array<Object>} merged participant rows
+ */
+function mergeChallengeWinnerParticipantRows (reviewRows, winnerRows) {
+  const mergedRows = (reviewRows || []).slice()
+  const existingKeys = new Set(mergedRows.map(buildParticipantRowKey))
+
+  ;(winnerRows || []).forEach((winnerRow) => {
+    const participantRow = toChallengeWinnerParticipantRow(winnerRow)
+    if (!participantRow) {
+      return
+    }
+
+    const key = buildParticipantRowKey(participantRow)
+    if (existingKeys.has(key)) {
+      return
+    }
+
+    existingKeys.add(key)
+    mergedRows.push(participantRow)
+  })
+
+  return mergedRows
+}
+
+/**
+ * Load ChallengeWinner rows for a target member. These rows let winner-only
+ * members enter the Development rating timeline even when review-api never
+ * wrote a challengeResult row for the completed challenge.
+ * @param {Object} challengeClient challenge Prisma client
+ * @param {BigInt|string|number} userId member identifier
+ * @returns {Promise<Array<Object>>} ChallengeWinner rows for rating replay
+ */
+async function fetchChallengeWinnerRowsForUser (challengeClient, userId) {
+  if (!challengeClient || !challengeClient.ChallengeWinner ||
+    typeof challengeClient.ChallengeWinner.findMany !== 'function') {
+    return []
+  }
+
+  return challengeClient.ChallengeWinner.findMany({
+    where: {
+      userId: toChallengeWinnerUserId(userId),
+      type: {
+        in: CHALLENGE_WINNER_RATING_TYPES
+      }
+    },
+    select: {
+      challengeId: true,
+      userId: true,
+      placement: true,
+      createdAt: true
+    }
+  })
+}
+
+/**
+ * Load ChallengeWinner participant rows for one challenge. The rows are merged
+ * with review-api participants so placement winners without challengeResult
+ * records still affect and receive Development rating updates.
+ * @param {Object} challengeClient challenge Prisma client
+ * @param {Object|string|number} challengeRef challenge id or history entry
+ * @returns {Promise<Array<Object>>} ChallengeWinner rows for the challenge
+ */
+async function fetchChallengeWinnerRowsForChallenge (challengeClient, challengeRef) {
+  if (!challengeClient || !challengeClient.ChallengeWinner ||
+    typeof challengeClient.ChallengeWinner.findMany !== 'function') {
+    return []
+  }
+
+  const challengeIds = buildChallengeIdCandidates(challengeRef)
+  if (challengeIds.length === 0) {
+    return []
+  }
+
+  return challengeClient.ChallengeWinner.findMany({
+    where: {
+      challengeId: {
+        in: challengeIds
+      },
+      type: {
+        in: CHALLENGE_WINNER_RATING_TYPES
+      }
+    },
+    select: {
+      challengeId: true,
+      userId: true,
+      placement: true,
+      createdAt: true
+    }
+  })
+}
+
 async function fetchReviewResultsForUser (reviewDbClient, userId) {
   const challengeResultRelation = await resolveChallengeResultRelation(reviewDbClient)
   const result = await reviewDbClient.query(
@@ -406,7 +548,7 @@ async function fetchReviewResultsForUser (reviewDbClient, userId) {
   return result.rows
 }
 
-async function fetchParticipantsForChallenge (reviewDbClient, challengeRef) {
+async function fetchParticipantsForChallenge (reviewDbClient, challengeRef, challengeClient) {
   const challengeIds = buildChallengeIdCandidates(challengeRef)
   if (challengeIds.length === 0) {
     return []
@@ -424,7 +566,8 @@ async function fetchParticipantsForChallenge (reviewDbClient, challengeRef) {
     challengeIds
   )
 
-  return result.rows
+  const winnerRows = await fetchChallengeWinnerRowsForChallenge(challengeClient, challengeRef)
+  return mergeChallengeWinnerParticipantRows(result.rows, winnerRows)
 }
 
 /**
@@ -951,8 +1094,12 @@ async function rerateDevTrack (membersClient, challengeClient, reviewDbClient, u
   }
 
   const normalizedUserId = toBigIntUserId(userId)
-  const reviewRows = await fetchReviewResultsForUser(reviewDbClient, normalizedUserId)
-  if (reviewRows.length === 0) {
+  const [reviewRows, winnerRows] = await Promise.all([
+    fetchReviewResultsForUser(reviewDbClient, normalizedUserId),
+    fetchChallengeWinnerRowsForUser(challengeClient, normalizedUserId)
+  ])
+  const participantRowsForUser = mergeChallengeWinnerParticipantRows(reviewRows, winnerRows)
+  if (participantRowsForUser.length === 0) {
     return {
       challengesProcessed: 0,
       ratingsUpdated: 0
@@ -961,10 +1108,10 @@ async function rerateDevTrack (membersClient, challengeClient, reviewDbClient, u
 
   const challengeMetadataById = await fetchChallengeMetadataMap(
     challengeClient,
-    Array.from(new Set(reviewRows.map((row) => String(row.challengeId))))
+    Array.from(new Set(participantRowsForUser.map((row) => String(row.challengeId))))
   )
 
-  const targetHistory = buildTargetHistory(reviewRows, challengeMetadataById, {
+  const targetHistory = buildTargetHistory(participantRowsForUser, challengeMetadataById, {
     skipLegacyReviewIds: options.skipLegacyReviewIds === true,
     useLegacySourceRatings: options.useLegacySourceRatings === true
   })
@@ -1062,7 +1209,7 @@ async function rerateDevTrack (membersClient, challengeClient, reviewDbClient, u
       continue
     }
 
-    const participantRows = (await fetchParticipantsForChallenge(reviewDbClient, historyEntry))
+    const participantRows = (await fetchParticipantsForChallenge(reviewDbClient, historyEntry, challengeClient))
       .filter((row) => isParticipantEligibleForRating(row))
     if (participantRows.length === 0) {
       continue

src/services/StatisticsService.js

@@ -71,6 +71,7 @@ const RERATE_MARATHON_ACTOR = 'rerate-mm-stats'
 const CHALLENGE_WINNER_PLACEMENT_TYPE = 'PLACEMENT'
 const CHALLENGE_WINNER_PASSED_REVIEW_TYPE = 'PASSED_REVIEW'
 const CHALLENGE_WINNER_HISTORY_TYPES = [CHALLENGE_WINNER_PLACEMENT_TYPE, CHALLENGE_WINNER_PASSED_REVIEW_TYPE]
+const CHALLENGE_WINNER_RATING_TYPES = [CHALLENGE_WINNER_PLACEMENT_TYPE]
 
 /**
  * Join Prisma SQL condition fragments with a literal AND separator.
@@ -536,6 +537,35 @@ async function fetchChallengeResultParticipantIds (reviewDbClient, challengeId)
   return result.rows.map((row) => toBigIntUserId(row.userId))
 }
 
+/**
+ * Fetch placement winner participants from challenge-api for completed
+ * Development rating rerates. This covers QA-created challenges where winners
+ * can be assigned without a review-api challengeResult row for the same member.
+ * @param {Object} challengeClient challenge Prisma client
+ * @param {string|number} challengeId challenge identifier
+ * @returns {Promise<Array<BigInt>>} winner user ids
+ */
+async function fetchChallengeWinnerParticipantIds (challengeClient, challengeId) {
+  if (!challengeClient || !challengeClient.ChallengeWinner ||
+    typeof challengeClient.ChallengeWinner.findMany !== 'function') {
+    return []
+  }
+
+  const winnerRows = await challengeClient.ChallengeWinner.findMany({
+    where: {
+      challengeId: String(challengeId),
+      type: {
+        in: CHALLENGE_WINNER_RATING_TYPES
+      }
+    },
+    select: {
+      userId: true
+    }
+  })
+
+  return winnerRows.map((row) => toBigIntUserId(row.userId))
+}
+
 /**
  * Fetch Marathon Match participants from review summations when challengeResult
  * rows are not available yet.
@@ -561,12 +591,20 @@ async function fetchMarathonMatchParticipantIds (reviewDbClient, challengeId) {
  * review summations so partially synced result rows cannot omit lower-placed
  * participants from rerating.
  * @param {Object} reviewDbClient raw pg review database client
+ * @param {Object} challengeClient challenge Prisma client
  * @param {string|number} challengeId challenge identifier
  * @param {string} source rating source identifier
  * @returns {Promise<Array<BigInt>>} unique participant user ids
  */
-async function fetchRatingParticipantIds (reviewDbClient, challengeId, source) {
+async function fetchRatingParticipantIds (reviewDbClient, challengeClient, challengeId, source) {
   const challengeResultUserIds = await fetchChallengeResultParticipantIds(reviewDbClient, challengeId)
+  if (source === RATING_SOURCE_DEVELOPMENT) {
+    return _.uniqBy(
+      challengeResultUserIds.concat(await fetchChallengeWinnerParticipantIds(challengeClient, challengeId)),
+      stringifyUserId
+    )
+  }
+
   if (source !== RATING_SOURCE_MARATHON_MATCH) {
     return _.uniqBy(challengeResultUserIds, stringifyUserId)
   }
@@ -4199,7 +4237,7 @@ async function rerateChallengeSubmitterRatings (currentUser, data) {
 
     participantIdsBySource.set(
       job.source,
-      await fetchRatingParticipantIds(reviewDbClient, challengeId, job.source)
+      await fetchRatingParticipantIds(reviewDbClient, challengeClient, challengeId, job.source)
     )
   }