Dart modelgen null safety (#195)

* feat(appsync-modelgen-plugin): add null safety support in dart

Author: phani-srikar

.circleci/config.base.yml

@@ -235,6 +235,7 @@ workflows:
               only:
                 - master
                 - e2e-testing
+                - dart-modelgen-null-safety
       - e2e-test:
           context:
             - cleanup-resources
@@ -248,6 +249,7 @@ workflows:
               only:
                 - master
                 - e2e-testing
+                - dart-modelgen-null-safety
       - deploy:
           os: linux_node12
           requires:
@@ -259,6 +261,7 @@ workflows:
               only:
                 - release
                 - master
+                - dart-modelgen-null-safety
       - done_with_node_e2e_tests:
           os: linux_node12
           requires:

.circleci/config.yml

@@ -420,6 +420,7 @@ workflows:
               only:
                 - master
                 - e2e-testing
+                - dart-modelgen-null-safety
       - deploy:
           os: linux_node12
           requires:
@@ -431,6 +432,7 @@ workflows:
               only:
                 - release
                 - master
+                - dart-modelgen-null-safety
       - done_with_node_e2e_tests:
           os: linux_node12
           requires:
@@ -469,6 +471,7 @@ workflows:
               only:
                 - master
                 - e2e-testing
+                - dart-modelgen-null-safety
       - add-codegen-android-e2e-test:
           context: *ref_8
           os: linux_node12

package.json

@@ -13,6 +13,7 @@
     "production-build": "yarn && lerna run build --concurrency 3 --stream",
     "publish:master": "lerna publish --canary --exact --force-publish --preid=dev --dist-tag=dev --include-merged-tags --conventional-prerelease --yes",
     "publish:release": "lerna publish --exact --conventional-commits --message 'chore(release): Publish [ci skip]' --yes",
+    "publish:dart-modelgen-null-safety": "lerna publish --canary --exact --force-publish --preid=flutter-preview --dist-tag=flutter-preview --include-merged-tags --conventional-prerelease --yes",
     "postpublish:release": "git fetch . release:master && git push origin master",
     "yarn-use-bash": "yarn config set script-shell /bin/bash",
     "verdaccio-start": "yarn yarn-use-bash && source .circleci/local_publish_helpers.sh && startLocalRegistry \"$(pwd)/.circleci/verdaccio.yaml\"",

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

@@ -5,12 +5,13 @@ import { pathManager } from 'amplify-cli-core';
 const codegenFeatureFlags = {
     "handlelistnullabilitytransparently": true,
     "addtimestampfields": true,
-    "generateIndexRules": true,
     "useappsyncmodelgenplugin": true,
     "usedocsgeneratorplugin": true,
     "usetypesgeneratorplugin": true,
     "cleangeneratedmodelsdirectory": true,
-    "retaincasestyle": true
+    "retaincasestyle": true,
+    "generateindexrules": true,
+    "emitauthprovider": true,
 };
 
 describe('codegen related feature flags - new project', () => {

packages/amplify-codegen/package.json

@@ -35,7 +35,9 @@
     "graphql-config": "^2.2.1",
     "inquirer": "^7.3.3",
     "ora": "^4.0.3",
-    "slash": "^3.0.0"
+    "slash": "^3.0.0",
+    "js-yaml": "^4.0.0",
+    "semver": "^7.3.5"
   },
   "peerDependencies": {
     "amplify-cli-core": "^1.17.2",

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

@@ -5,6 +5,7 @@ const glob = require('glob-all');
 const { FeatureFlags, pathManager } = require('amplify-cli-core');
 const gqlCodeGen = require('@graphql-codegen/core');
 const { getModelgenPackage } = require('../utils/getModelgenPackage');
+const { validateDartSDK } = require('../utils/validateDartSDK');
 
 const platformToLanguageMap = {
   android: 'java',
@@ -18,15 +19,15 @@ const platformToLanguageMap = {
  * @param {string} key feature flag id
  * @returns
  */
-const readFeatureFlag = (key) => {
+const readFeatureFlag = key => {
   let flagValue = false;
   try {
     flagValue = FeatureFlags.getBoolean(key);
   } catch (err) {
     flagValue = false;
   }
   return flagValue;
-}
+};
 
 async function generateModels(context) {
   // steps:
@@ -72,6 +73,22 @@ async function generateModels(context) {
   const generateIndexRules = readFeatureFlag('codegen.generateIndexRules');
   const emitAuthProvider = readFeatureFlag('codegen.emitAuthProvider');
 
+  let enableDartNullSafety = readFeatureFlag('codegen.enableDartNullSafety');
+
+  if (projectConfig.frontend === 'flutter') {
+    const isMinimumDartVersionSatisfied = validateDartSDK(context, projectRoot);
+    context.print.warning(`Detected feature flag: “enableDartNullSafety : ${enableDartNullSafety}”`);
+    if (isMinimumDartVersionSatisfied && enableDartNullSafety) {
+      context.print.warning(
+        'Generating Dart Models with null safety. To opt out of null safe models, turn off the “enableDartNullSafety” feature flag. Learn more: https://docs.amplify.aws/lib/project-setup/null-safety/q/platform/flutter',
+      );
+    } else {
+      enableDartNullSafety = false;
+      context.print.warning(
+        'Generating Dart Models without null safety. To generate null safe data models, turn on the “enableDartNullSafety” feature flag and set your Dart SDK version to “>= 2.12.0”. Learn more: https://docs.amplify.aws/lib/project-setup/null-safety/q/platform/flutter',
+      );
+    }
+  }
   const appsyncLocalConfig = await appSyncDataStoreCodeGen.preset.buildGeneratesSection({
     baseOutputDir: outputPath,
     schema,
@@ -81,6 +98,7 @@ async function generateModels(context) {
       isTimestampFieldsAdded,
       emitAuthProvider,
       generateIndexRules,
+      enableDartNullSafety,
     },
   });
 

packages/amplify-codegen/src/utils/validateDartSDK.js

@@ -0,0 +1,24 @@
+const yaml = require('js-yaml');
+const path = require('path');
+const fs = require('fs-extra');
+const semver = require('semver');
+
+const PUBSPEC_FILE_NAME = 'pubspec.yaml';
+
+function validateDartSDK(context, projectRoot) {
+  try {
+    const config = yaml.load(fs.readFileSync(path.join(projectRoot, PUBSPEC_FILE_NAME), 'utf8'));
+    const version = semver.minVersion(config.environment.sdk);
+    if (semver.satisfies(version, '>= 2.12.0')) {
+      context.print.warning('\nDetected Dart SDK version 2.12.0 or above');
+      return true;
+    }
+    context.print.warning('\nDetected Dart SDK version below 2.12.0');
+    return false;
+  } catch (e) {
+    context.print.warning('\nCould not detect Dart SDK version, defaulting to 2.12.0');
+    return true;
+  }
+}
+
+module.exports = { PUBSPEC_FILE_NAME, validateDartSDK };