test: add flutter pubspec.lock file

Author: phani-srikar

packages/amplify-codegen-e2e-tests/src/__tests__/pull-codegen.test.ts

@@ -116,6 +116,10 @@ describe('Amplify pull in sandbox app with codegen tests', () => {
     it(`should pull sandbox, download schema and generate models without deleting user files in ${config.frontendType} project`, async () => {
       //generate pre existing user file
       const userSourceCodePath = generateSourceCode(projectRoot, config.srcDir);
+      // Flutter projects need min dart version to be met for modelgen to succeed.
+      if (config?.frontendType === AmplifyFrontend.flutter) {
+        createPubspecLockFile(projectRoot);
+      };
       //pull sandbox app
       await amplifyPullSandbox(projectRoot, {
         appType: config.frontendType,

packages/amplify-codegen-e2e-tests/src/codegen-tests-base/datastore-modelgen.ts

@@ -25,16 +25,17 @@ export async function testCodegenModels(config: AmplifyFrontendConfig, projectRo
     //generate pre existing user file
     const userSourceCodePath = generateSourceCode(projectRoot, config.srcDir);
 
+    // For flutter frontend, we need to have a pubspec lock file with supported dart version
+    if (config?.frontendType === AmplifyFrontend.flutter) {
+        createPubspecLockFile(projectRoot);
+    }
+
     //generate models
     await expect(generateModels(projectRoot, outputDir)).resolves.not.toThrow();
 
     // pre-existing file should still exist
     expect(existsSync(userSourceCodePath)).toBe(true);
 
-    // For flutter frontend, we need to have a pubspec lock file with supported dart version
-    if (config?.frontendType === AmplifyFrontend.flutter) {
-        createPubspecLockFile(projectRoot);
-    }
     // datastore models are generated at correct location
     const dirToCheck = outputDir
         ? path.join(projectRoot, outputDir)