Add Swift code generation test that verifies that, when there are nes…

…ted fragment refrences, the correct source + fragments is generated for the operation id mapping file

test/swift/__snapshots__/codeGeneration.js.snap

@@ -642,6 +642,21 @@ exports[`Swift code generation #classDeclarationForOperation() when generateOper
 }"
 `;
 
+exports[`Swift code generation #classDeclarationForOperation() when generateOperationIds is specified should generate appropriate operation id mapping source when there are nested fragment references 1`] = `
+"query Hero {
+  hero {
+    ...HeroDetails
+  }
+}
+fragment HeroDetails on Character {
+  ...HeroName
+  appearsIn
+}
+fragment HeroName on Character {
+  name
+}"
+`;
+
 exports[`Swift code generation #initializerDeclarationForProperties() should generate initializer for a property 1`] = `
 "public init(episode: Episode) {
   self.episode = episode

test/swift/codeGeneration.js

@@ -264,6 +264,26 @@ describe('Swift code generation', function() {
 
         expect(output1).toBe(output2);
       });
+
+      test(`should generate appropriate operation id mapping source when there are nested fragment references`, function() {
+        const source = `
+          query Hero {
+            hero {
+              ...HeroDetails
+            }
+          }
+          fragment HeroName on Character {
+            name
+          }
+          fragment HeroDetails on Character {
+            ...HeroName
+            appearsIn
+          }
+        `;
+        const context = compileFromSource(source, true);
+        expect(context.operations['Hero'].sourceWithFragments).toMatchSnapshot();
+      });
+
     });
   });