fix(graphql-relational-transformer): nullability enforcement for references relational fields

packages/amplify-graphql-relational-transformer/src/__tests__/__snapshots__/amplify-graphql-belongs-to-transformer.test.ts.snap

@@ -10,7 +10,7 @@ exports[`@belongsTo directive with RDS datasource composite key should generate
 type Profile {
   profileId: String!
   userFirstName: String
-  userLastName: String!
+  userLastName: String
   user: User
 }
 
@@ -255,7 +255,7 @@ input ModelProfileConditionInput {
 input CreateProfileInput {
   profileId: String!
   userFirstName: String
-  userLastName: String!
+  userLastName: String
 }
 
 input UpdateProfileInput {

packages/amplify-graphql-relational-transformer/src/__tests__/__snapshots__/amplify-graphql-has-one-transformer.test.ts.snap

@@ -10,7 +10,7 @@ exports[`@hasOne directive with RDS datasource composite key should generate cor
 type Profile {
   profileId: String!
   userFirstName: String
-  userLastName: String!
+  userLastName: String
   user: User
 }
 
@@ -255,7 +255,7 @@ input ModelProfileConditionInput {
 input CreateProfileInput {
   profileId: String!
   userFirstName: String
-  userLastName: String!
+  userLastName: String
 }
 
 input UpdateProfileInput {

packages/amplify-graphql-relational-transformer/src/__tests__/amplify-graphql-belongs-to-transformer.test.ts

@@ -458,7 +458,7 @@ test('Should not resolve to secondary index of connected model if the index is d
       content: String! @index
       comments: [Comment] @hasMany(indexName:"byParent", fields:["customId", "content"])
     }
-    
+
     type Comment @model {
       childId: ID! @primaryKey(sortKeyFields:["content"])
       content: String!
@@ -783,7 +783,7 @@ describe('@belongsTo directive with RDS datasource', () => {
       type Profile @model {
         profileId: String! @primaryKey
         userFirstName: String
-        userLastName: String!
+        userLastName: String
         user: User @belongsTo(references: ["userFirstName", "userLastName"])
       }
     `;

packages/amplify-graphql-relational-transformer/src/__tests__/amplify-graphql-has-many-references-transformer.test.ts

@@ -185,7 +185,7 @@ test('fails if used as a has one relationship', () => {
     type Member @model {
       id: ID!
       teamID: String
-      team: Team @belongsTo(fields: ["teamID"])
+      team: Team @belongsTo(references: ["teamID"])
     }`;
 
   expect(() =>
@@ -196,6 +196,118 @@ test('fails if used as a has one relationship', () => {
   ).toThrowError('@hasMany must be used with a list. Use @hasOne for non-list types.');
 });
 
+test('fails if primary relational field list type is required', () => {
+  const inputSchema = `
+    type Team @model {
+      id: ID!
+      name: String!
+      members: [Member]! @hasMany(references: ["teamID"])
+    }
+    type Member @model {
+      id: ID!
+      teamID: String
+      team: Team @belongsTo(references: ["teamID"])
+    }`;
+
+  expect(() =>
+    testTransform({
+      schema: inputSchema,
+      transformers: [new ModelTransformer(), new HasManyTransformer(), new BelongsToTransformer()],
+    }),
+  ).toThrowError("@hasMany fields must not be required. Change 'Team.members: [Member]!' to 'Team.members: [Member]'");
+});
+
+test('fails if primary relational field element type required', () => {
+  const inputSchema = `
+    type Team @model {
+      id: ID!
+      name: String!
+      members: [Member!] @hasMany(references: ["teamID"])
+    }
+    type Member @model {
+      id: ID!
+      teamID: String
+      team: Team @belongsTo(references: ["teamID"])
+    }`;
+
+  expect(() =>
+    testTransform({
+      schema: inputSchema,
+      transformers: [new ModelTransformer(), new HasManyTransformer(), new BelongsToTransformer()],
+    }),
+  ).toThrowError("@hasMany fields must not be required. Change 'Team.members: [Member!]' to 'Team.members: [Member]'");
+});
+
+test('fails if primary relational field list type and element type are required', () => {
+  const inputSchema = `
+    type Team @model {
+      id: ID!
+      name: String!
+      members: [Member!]! @hasMany(references: ["teamID"])
+    }
+    type Member @model {
+      id: ID!
+      teamID: String
+      team: Team @belongsTo(references: ["teamID"])
+    }`;
+
+  expect(() =>
+    testTransform({
+      schema: inputSchema,
+      transformers: [new ModelTransformer(), new HasManyTransformer(), new BelongsToTransformer()],
+    }),
+  ).toThrowError("@hasMany fields must not be required. Change 'Team.members: [Member]!' to 'Team.members: [Member]'");
+});
+
+test('fails if related relational field is required', () => {
+  const inputSchema = `
+    type Team @model {
+      id: ID!
+      name: String!
+      members: [Member] @hasMany(references: ["teamID"])
+    }
+    type Member @model {
+      id: ID!
+      teamID: String
+      team: Team! @belongsTo(references: ["teamID"])
+    }`;
+
+  expect(() =>
+    testTransform({
+      schema: inputSchema,
+      transformers: [new ModelTransformer(), new HasManyTransformer(), new BelongsToTransformer()],
+    }),
+  ).toThrowError("@belongsTo fields must not be required. Change 'Member.team: Team!' to 'Member.team: Team'");
+});
+
+test('fails with inconsistent nullability of reference fields', () => {
+  const inputSchema = `
+    type Member @model {
+      name: String
+      teamId: String!
+      teamMantra: String
+      team: Team @belongsTo(references: ["teamId", "teamMantra"])
+    }
+    type Team @model {
+      id: String! @primaryKey(sortKeyFields: ["mantra"])
+      mantra: String!
+      members: [Member] @hasMany(references: ["teamId", "teamMantra"])
+    }
+  `;
+
+  expect(() =>
+    testTransform({
+      schema: inputSchema,
+      transformers: [new ModelTransformer(), new PrimaryKeyTransformer(), new HasManyTransformer(), new BelongsToTransformer()],
+    }),
+  ).toThrowError(
+    "Reference fields defined on related type: 'Member' for @hasMany(references: ['teamId', 'teamMantra']) Team.members relationship have inconsistent nullability." +
+      "\nRequired fields: 'teamId'" +
+      "\nNullable fields: 'teamMantra'" +
+      "\nUpdate reference fields on type 'Member' to have consistent nullability -- either all required or all nullable.",
+  );
+});
+
 test('hasMany / hasOne - belongsTo across data source type boundary', () => {
   const mockSqlStrategy = mockSqlDataSourceStrategy();
 
@@ -215,7 +327,7 @@ test('hasMany / hasOne - belongsTo across data source type boundary', () => {
     type Team @model {
       id: String! @primaryKey
       mantra: String
-      members: [Member!] @hasMany(references: "teamId")
+      members: [Member] @hasMany(references: "teamId")
       project: Project @hasOne(references: "teamId")
     }
   `;

packages/amplify-graphql-relational-transformer/src/__tests__/amplify-graphql-has-one-references-transformer.test.ts

@@ -277,6 +277,79 @@ test('fails if object type fields are provided', () => {
   ).toThrowError('All reference fields provided to @hasOne must be scalar or enum fields.');
 });
 
+test('fails if primary relational field is required', () => {
+  const inputSchema = `
+  type Project @model {
+    name: String
+    teamId: String
+    team: Team @belongsTo(references: "teamId")
+  }
+
+  type Team @model {
+    id: String!
+    mantra: String
+    project: Project! @hasOne(references: "teamId")
+  }`;
+
+  expect(() =>
+    testTransform({
+      schema: inputSchema,
+      transformers: [new ModelTransformer(), new HasOneTransformer(), new BelongsToTransformer()],
+    }),
+  ).toThrowError("@hasOne fields must not be required. Change 'Team.project: Project!' to 'Team.project: Project'");
+});
+
+test('fails if related relational field is required', () => {
+  const inputSchema = `
+  type Project @model {
+    name: String
+    teamId: String
+    team: Team! @belongsTo(references: "teamId")
+  }
+
+  type Team @model {
+    id: String!
+    mantra: String
+    project: Project @hasOne(references: "teamId")
+  }`;
+
+  expect(() =>
+    testTransform({
+      schema: inputSchema,
+      transformers: [new ModelTransformer(), new HasOneTransformer(), new BelongsToTransformer()],
+    }),
+  ).toThrowError("@belongsTo fields must not be required. Change 'Project.team: Team!' to 'Project.team: Team'");
+});
+
+test('fails with inconsistent nullability of reference fields', () => {
+  const inputSchema = `
+    type Project @model {
+      name: String
+      teamId: String!
+      teamMantra: String
+      team: Team @belongsTo(references: ["teamId", "teamMantra"])
+    }
+
+    type Team @model {
+      id: String! @primaryKey(sortKeyFields: ["mantra"])
+      mantra: String!
+      project: Project @hasOne(references: ["teamId", "teamMantra"])
+    }
+  `;
+
+  expect(() =>
+    testTransform({
+      schema: inputSchema,
+      transformers: [new ModelTransformer(), new PrimaryKeyTransformer(), new HasOneTransformer(), new BelongsToTransformer()],
+    }),
+  ).toThrowError(
+    "Reference fields defined on related type: 'Project' for @hasOne(references: ['teamId', 'teamMantra']) Team.project relationship have inconsistent nullability." +
+      "\nRequired fields: 'teamId'" +
+      "\nNullable fields: 'teamMantra'" +
+      "\nUpdate reference fields on type 'Project' to have consistent nullability -- either all required or all nullable.",
+  );
+});
+
 test('has one references single partition key', () => {
   const inputSchema = `
     type Project @model {

packages/amplify-graphql-relational-transformer/src/__tests__/amplify-graphql-has-one-transformer.test.ts

@@ -797,7 +797,7 @@ describe('@hasOne directive with RDS datasource', () => {
       type Profile @model {
         profileId: String! @primaryKey
         userFirstName: String
-        userLastName: String!
+        userLastName: String
         user: User @belongsTo(references: ["userFirstName", "userLastName"])
       }
     `;

packages/amplify-graphql-relational-transformer/src/belongs-to/belongs-to-directive-ddb-references-transformer.ts

@@ -14,6 +14,7 @@ import {
   registerHasOneForeignKeyMappings,
   validateChildReferencesFields,
   validateReferencesBidirectionality,
+  validateReferencesRelationalFieldNullability,
 } from '../utils';
 
 /**
@@ -54,6 +55,7 @@ export class BelongsToDirectiveDDBReferencesTransformer implements DataSourceBas
   validate = (context: TransformerContextProvider, config: BelongsToDirectiveConfiguration): void => {
     ensureReferencesArray(config);
     validateChildReferencesFields(config, context as TransformerContextProvider);
+    validateReferencesRelationalFieldNullability(config);
     config.referenceNodes = getBelongsToReferencesNodes(config, context);
     validateReferencesBidirectionality(config);
   };

packages/amplify-graphql-relational-transformer/src/belongs-to/belongs-to-directive-sql-transformer.ts

@@ -13,6 +13,7 @@ import {
   getBelongsToReferencesNodes,
   validateChildReferencesFields,
   validateReferencesBidirectionality,
+  validateReferencesRelationalFieldNullability,
 } from '../utils';
 
 /**
@@ -39,6 +40,7 @@ export class BelongsToDirectiveSQLTransformer implements DataSourceBasedDirectiv
   validate = (context: TransformerContextProvider, config: BelongsToDirectiveConfiguration): void => {
     ensureReferencesArray(config);
     config.referenceNodes = getBelongsToReferencesNodes(config, context);
+    validateReferencesRelationalFieldNullability(config);
     validateReferencesBidirectionality(config);
   };
 }

packages/amplify-graphql-relational-transformer/src/has-many/has-many-directive-ddb-references-transformer.ts

@@ -18,6 +18,7 @@ import {
   registerHasManyForeignKeyMappings,
   validateParentReferencesFields,
   validateReferencesBidirectionality,
+  validateReferencesRelationalFieldNullability,
 } from '../utils';
 
 /**
@@ -66,11 +67,11 @@ export class HasManyDirectiveDDBReferencesTransformer implements DataSourceBased
     }
     ensureReferencesArray(config);
     validateParentReferencesFields(config, context);
+    validateReferencesRelationalFieldNullability(config);
     const objectName = config.object.name.value;
     const fieldName = config.field.name.value;
     config.indexName = `gsi-${objectName}.${fieldName}`;
     config.referenceNodes = getReferencesNodes(config, context);
-
     validateReferencesBidirectionality(config);
   };
 }

packages/amplify-graphql-relational-transformer/src/has-many/has-many-directive-sql-transformer.ts

@@ -8,7 +8,13 @@ import { DataSourceBasedDirectiveTransformer } from '../data-source-based-direct
 import { getGenerator } from '../resolver/generator-factory';
 import { setFieldMappingResolverReference } from '../resolvers';
 import { HasManyDirectiveConfiguration } from '../types';
-import { ensureReferencesArray, getReferencesNodes, validateParentReferencesFields, validateReferencesBidirectionality } from '../utils';
+import {
+  ensureReferencesArray,
+  getReferencesNodes,
+  validateParentReferencesFields,
+  validateReferencesBidirectionality,
+  validateReferencesRelationalFieldNullability,
+} from '../utils';
 
 /**
  * HasManyDirectiveSQLTransformer executes transformations based on `@hasMany(references: [String!])` configurations
@@ -34,6 +40,7 @@ export class HasManyDirectiveSQLTransformer implements DataSourceBasedDirectiveT
   validate = (context: TransformerContextProvider, config: HasManyDirectiveConfiguration): void => {
     ensureReferencesArray(config);
     config.referenceNodes = getReferencesNodes(config, context);
+    validateReferencesRelationalFieldNullability(config);
     validateReferencesBidirectionality(config);
   };
 }

packages/amplify-graphql-relational-transformer/src/has-one/has-one-directive-ddb-references-transformer.ts

@@ -18,6 +18,7 @@ import {
   registerHasOneForeignKeyMappings,
   validateParentReferencesFields,
   validateReferencesBidirectionality,
+  validateReferencesRelationalFieldNullability,
 } from '../utils';
 
 /**
@@ -66,6 +67,7 @@ export class HasOneDirectiveDDBReferencesTransformer implements DataSourceBasedD
     }
     ensureReferencesArray(config);
     validateParentReferencesFields(config, context);
+    validateReferencesRelationalFieldNullability(config);
     const objectName = config.object.name.value;
     const fieldName = config.field.name.value;
     config.indexName = `gsi-${objectName}.${fieldName}`;

packages/amplify-graphql-relational-transformer/src/has-one/has-one-directive-sql-transformer.ts

@@ -7,7 +7,13 @@ import {
 import { DataSourceBasedDirectiveTransformer } from '../data-source-based-directive-transformer';
 import { setFieldMappingResolverReference } from '../resolvers';
 import { HasOneDirectiveConfiguration } from '../types';
-import { ensureReferencesArray, getReferencesNodes, validateParentReferencesFields, validateReferencesBidirectionality } from '../utils';
+import {
+  ensureReferencesArray,
+  getReferencesNodes,
+  validateParentReferencesFields,
+  validateReferencesBidirectionality,
+  validateReferencesRelationalFieldNullability,
+} from '../utils';
 import { getGenerator } from '../resolver/generator-factory';
 
 /**
@@ -34,6 +40,7 @@ export class HasOneDirectiveSQLTransformer implements DataSourceBasedDirectiveTr
   validate = (context: TransformerContextProvider, config: HasOneDirectiveConfiguration): void => {
     ensureReferencesArray(config);
     config.referenceNodes = getReferencesNodes(config, context);
+    validateReferencesRelationalFieldNullability(config);
     validateReferencesBidirectionality(config);
   };
 }