fix(betterer 🐛): add missing diff to summary when run is better (#959)

Author: phenomnomnominal

packages/betterer/src/run/worker-run.ts

@@ -203,12 +203,13 @@ export class BettererWorkerRunΩ implements BettererRun {
           return end(BettererRunStatus.same, result);
         }
 
+        const diff = this.test.differ(this.expected.value, result.value);
         if (comparison === BettererConstraintResult.better) {
-          return end(BettererRunStatus.better, result);
+          return end(BettererRunStatus.better, result, diff);
         }
 
         const status = config.update ? BettererRunStatus.update : BettererRunStatus.worse;
-        return end(status, result, this.test.differ(this.expected.value, result.value));
+        return end(status, result, diff);
       },
       failed: async (error: BettererError): Promise<BettererRunSummary> => {
         return end(BettererRunStatus.failed, null, null, error);

test/better-result.spec.ts

@@ -43,6 +43,9 @@ module.exports = {
 
     expect(testNames(secondRun.better)).toEqual(['should shrink', 'should grow']);
 
+    const [betterSummary] = secondRun.better;
+    expect(betterSummary.diff).toBeDefined();
+
     expect(logs).toMatchSnapshot();
 
     const result = await readFile(resultsPath);

test/worse-result.spec.ts

@@ -43,6 +43,9 @@ module.exports = {
 
     expect(testNames(secondRun.worse)).toEqual(['should shrink', 'should grow']);
 
+    const [worseSummary] = secondRun.worse;
+    expect(worseSummary.diff).toBeDefined();
+
     expect(logs).toMatchSnapshot();
 
     const result = await readFile(resultsPath);