fix(score-result): Wrap single file reports

packages/stryker/src/ScoreResultCalculator.ts

@@ -5,11 +5,11 @@ import { MutationScoreThresholds } from 'stryker-api/core';
 import { MutantResult, MutantStatus, ScoreResult } from 'stryker-api/report';
 import { freezeRecursively, setExitCode } from './utils/objectUtils';
 
-
 export default class ScoreResultCalculator {
 
   static calculate(results: MutantResult[]): ScoreResult {
-    return this.calculateScoreResult(results, '');
+    const scoreResult = this.calculateScoreResult(results, '');
+    return this.wrapIfSingleFileScoreResult(scoreResult);
   }
 
   static determineExitCode(score: ScoreResult, thresholds: MutationScoreThresholds | undefined) {
@@ -28,20 +28,36 @@ export default class ScoreResultCalculator {
     }
   }
 
+  private static wrapIfSingleFileScoreResult(scoreResult: ScoreResult): ScoreResult {
+    if (scoreResult.representsFile) {
+      return this.copy(scoreResult, {
+        name: path.dirname(scoreResult.name), childResults: [
+          this.copy(scoreResult, { name: path.basename(scoreResult.name) })
+        ]
+      });
+    } else {
+      return scoreResult;
+    }
+  }
+
   private static calculateScoreResult(results: MutantResult[], basePath: string): ScoreResult {
     const numbers = this.countNumbers(results);
     const facts = this.determineFacts(basePath, results);
     return freezeRecursively(_.assign(numbers, facts));
   }
 
+  private static copy(defaults: ScoreResult, overrides: Partial<ScoreResult>): ScoreResult {
+    return Object.assign({}, defaults, overrides);
+  }
+
   private static determineFacts(basePath: string, results: MutantResult[]) {
     const name = this.determineCommonBasePath(results, basePath);
     const childResults = this.calculateChildScores(results, name, basePath);
     return {
       name,
       path: path.join(basePath, name),
       childResults,
-      representsFile: childResults.length === 0
+      representsFile: childResults.length === 0 && results.length > 0
     };
   }
 

packages/stryker/test/unit/ScoreResultCalculatorSpec.ts

@@ -22,18 +22,31 @@ describe('ScoreResult', () => {
         mutantResult({ status: MutantStatus.Killed, sourceFilePath: fileName }),
         mutantResult({ status: MutantStatus.TimedOut, sourceFilePath: fileName }),
       ]);
-      expect(actual.name).to.eq(fileName);
-      expect(actual.killed, 'killed').to.eq(2);
-      expect(actual.survived, 'survived').to.eq(1);
-      expect(actual.noCoverage, 'noCoverage').to.eq(1);
-      expect(actual.timedOut, 'timedOut').to.eq(1);
-      expect(actual.totalCovered, 'totalCovered').to.eq(4);
-      expect(actual.totalDetected, 'detected').to.eq(3);
-      expect(actual.totalMutants, 'mutants').to.eq(5);
-      expect(actual.totalUndetected, 'undetected').to.eq(2);
-      expect(actual.mutationScoreBasedOnCoveredCode, 'percentageBasedOnCoveredCode').to.eq(75);
-      expect(actual.mutationScore, 'mutationScore').to.eq(60);
-      expect(actual.childResults).to.have.lengthOf(0);
+      expect(actual.name).to.eq('base');
+      function assertNumbers(actual: ScoreResult) {
+        expect(actual.killed, 'killed').to.eq(2);
+        expect(actual.survived, 'survived').to.eq(1);
+        expect(actual.noCoverage, 'noCoverage').to.eq(1);
+        expect(actual.timedOut, 'timedOut').to.eq(1);
+        expect(actual.totalCovered, 'totalCovered').to.eq(4);
+        expect(actual.totalDetected, 'detected').to.eq(3);
+        expect(actual.totalMutants, 'mutants').to.eq(5);
+        expect(actual.totalUndetected, 'undetected').to.eq(2);
+        expect(actual.mutationScoreBasedOnCoveredCode, 'percentageBasedOnCoveredCode').to.eq(75);
+        expect(actual.mutationScore, 'mutationScore').to.eq(60);
+      }
+      assertNumbers(actual);
+      assertNumbers(actual.childResults[0]);
+    });
+
+    it('should wrap a single result in its base directory', () => {
+      const fileName = path.join('base', 'something');
+      const actual = ScoreResultCalculator.calculate([
+        mutantResult({ status: MutantStatus.Error, sourceFilePath: fileName })
+      ]);
+      expect(actual.name).eq('base');
+      expect(actual.childResults).lengthOf(1);
+      expect(actual.childResults[0].name).eq('something');
     });
 
     it('should count results of multiple files', () => {