Fix: Implement Claim state machine with transitionTo helper (#200)

src/claims/claim-resolution.service.ts

@@ -1,7 +1,7 @@
 import { Injectable } from '@nestjs/common';
 import { Repository } from 'typeorm';
 import { InjectRepository } from '@nestjs/typeorm';
-import { Claim } from './entities/claim.entity';
+import { Claim, ClaimState } from './entities/claim.entity';
 import { ClaimsCache } from '../cache/claims.cache';
 
 interface VoteWeightSummary {
@@ -46,9 +46,12 @@ export class ClaimResolutionService {
     const verdict = votes.trueWeight > votes.falseWeight;
     const confidence = this.computeConfidenceScore(votes);
 
-    claim.resolvedVerdict = verdict;
-    claim.confidenceScore = confidence;
-    claim.finalized = true;
+    // Use transitionTo helper for validated state transition
+    // This transitions directly to FINALIZED with verdict and confidence
+    claim.transitionTo(ClaimState.FINALIZED, {
+      verdict,
+      confidence,
+    });
 
     const savedClaim = await this.claimRepo.save(claim);
     // Invalidate both the claim-specific cache and the latest claims list cache

src/claims/claims.service.ts

@@ -1,7 +1,7 @@
 import { Injectable, Logger } from '@nestjs/common';
 import { InjectRepository } from '@nestjs/typeorm';
 import { Repository } from 'typeorm';
-import { Claim } from './entities/claim.entity';
+import { Claim, ClaimState } from './entities/claim.entity';
 import { CreateClaimDto } from './dto/create-claim.dto';
 import { ClaimsCache } from '../cache/claims.cache';
 import { RedisService } from '../redis/redis.service';
@@ -112,6 +112,7 @@ export class ClaimsService {
 
     /**
      * Resolve a claim (update verdict and confidence)
+     * Uses state machine validation to ensure valid transitions
      */
     async resolveClaim(
         claimId: string,
@@ -124,8 +125,11 @@ export class ClaimsService {
 
         const beforeState = { ...claim };
 
-        claim.resolvedVerdict = verdict;
-        claim.confidenceScore = confidenceScore;
+        // Use transitionTo helper for validated state transition
+        claim.transitionTo(ClaimState.RESOLVED, {
+            verdict,
+            confidence: confidenceScore,
+        });
 
         const updatedClaim = await this.claimRepo.save(claim);
         // Invalidate both the claim-specific cache and the latest claims list cache
@@ -147,14 +151,17 @@ export class ClaimsService {
 
     /**
      * Finalize a claim
+     * Uses state machine validation to ensure valid transitions
      */
     async finalizeClaim(claimId: string, userId?: string): Promise<Claim> {
         const claim = await this.findOne(claimId);
         if (!claim) throw new Error(`Claim ${claimId} not found`);
 
         const beforeState = { ...claim };
 
-        claim.finalized = true;
+        // Use transitionTo helper for validated state transition
+        claim.transitionTo(ClaimState.FINALIZED);
+
         const updatedClaim = await this.claimRepo.save(claim);
         // Invalidate both the claim-specific cache and the latest claims list cache
         await this.claimsCache.invalidateClaim(claimId);