feat(amplify-codegen): iOS LazyReference and ModelPath (#504)

* feat(amplify-codegen): iOS LazyReference

* feat(amplify-codegen): optionality should be reflected in the computed property

* feat(amplify-codegen): add ModelPath extension

* feat(amplify-codegen): add mutating func to allow update/delete association

* feat(amplify-codegen): custom decoder encoder for LazyReference

* feat(amplify-codegen): custom decoder encoder for LazyReference 2

* feat(amplify-codegen): custom decoder encoder for LazyReference 3

* feat(amplify-codegen): custom decoder encoder for LazyReference 4

* feat(amplify-codegen): custom decoder encoder for LazyReference 5

* feat(amplify-codegen): address PR feedback

* feat(amplify-codegen): add feature flag generateLazyReferenceAndModelPath check

* feat(amplify-codegen): do not generate ModelPath for embedded types

* feat(amplify-codegen): do not generate custom encoder/decoder if not necessary

* feat(amplify-codegen): generate decodeIfPresent for List

* feat(amplify-codegen): feature flag rename

* feat(amplify-codegen): fix decoder for optional fields that are not connections

* feat(amplify-codegen): update regression test flag

Author: lawmicha

.gitignore

@@ -25,3 +25,4 @@ packages/**/reports/junit/*
 test.out.log
 *.tsbuildinfo
 package-lock.json
+.idea

packages/amplify-codegen/src/commands/models.js

@@ -103,6 +103,7 @@ async function generateModels(context, generateOptions = null) {
   const usePipelinedTransformer = readFeatureFlag('graphQLTransformer.useExperimentalPipelinedTransformer');
   const transformerVersion = readNumericFeatureFlag('graphQLTransformer.transformerVersion');
   const respectPrimaryKeyAttributesOnConnectionField = readFeatureFlag('graphQLTransformer.respectPrimaryKeyAttributesOnConnectionField');
+  const generateModelsForLazyLoadAndCustomSelectionSet = readFeatureFlag('codegen.generateModelsForLazyLoadAndCustomSelectionSet');
 
   let isTimestampFieldsAdded = readFeatureFlag('codegen.addTimestampFields');
   let enableDartNullSafety = readFeatureFlag('codegen.enableDartNullSafety');
@@ -146,6 +147,7 @@ async function generateModels(context, generateOptions = null) {
       transformerVersion,
       dartUpdateAmplifyCoreDependency,
       respectPrimaryKeyAttributesOnConnectionField,
+      generateModelsForLazyLoadAndCustomSelectionSet,
       codegenVersion: packageVersion,
       overrideOutputDir, // This needs to live under `config` in order for the GraphQL types to work out.
     },