fix: allow belongsTo relation with same table

Signed-off-by: Muhammad Aaqil <aaqilniz@yahoo.com>

packages/cli/generators/relation/base-relation.generator.js

@@ -77,6 +77,7 @@ module.exports = class BaseRelationGenerator extends ArtifactGenerator {
     const imports = this._getRepositoryRequiredImports(
       options.destinationModel,
       this.artifactInfo.dstRepositoryClassName,
+      options.sourceModel,
     );
 
     relationUtils.addRequiredImports(
@@ -187,8 +188,12 @@ module.exports = class BaseRelationGenerator extends ArtifactGenerator {
     this.artifactInfo.relationName = options.relationName;
   }
 
-  _getRepositoryRequiredImports(dstModelClassName, dstRepositoryClassName) {
-    return [
+  _getRepositoryRequiredImports(
+    dstModelClassName,
+    dstRepositoryClassName,
+    srcModelClass,
+  ) {
+    const imports = [
       {
         name: dstModelClassName,
         module: '../models',
@@ -201,11 +206,14 @@ module.exports = class BaseRelationGenerator extends ArtifactGenerator {
         name: 'Getter',
         module: '@loopback/core',
       },
-      {
+    ];
+    if (dstModelClassName !== srcModelClass) {
+      imports.push({
         name: dstRepositoryClassName,
         module: `./${utils.toFileName(dstModelClassName)}.repository`,
-      },
-    ];
+      });
+    }
+    return imports;
   }
 
   _getRepositoryRelationPropertyName() {

packages/cli/generators/relation/belongs-to-relation.generator.js

@@ -106,7 +106,11 @@ module.exports = class BelongsToRelationGenerator extends (
     );
 
     relationUtils.addProperty(sourceClass, modelProperty);
-    const imports = relationUtils.getRequiredImports(targetModel, relationType);
+    const imports = relationUtils.getRequiredImports(
+      targetModel,
+      relationType,
+      sourceModel,
+    );
     relationUtils.addRequiredImports(sourceFile, imports);
 
     sourceClass.formatText();
@@ -147,6 +151,7 @@ module.exports = class BelongsToRelationGenerator extends (
     const importsArray = super._getRepositoryRequiredImports(
       dstModelClassName,
       dstRepositoryClassName,
+      this.artifactInfo.srcModelClass,
     );
     importsArray.push({
       name: 'BelongsToAccessor',

packages/cli/generators/relation/templates/controller-relation-template-belongs-to.ts.ejs

@@ -6,8 +6,8 @@ import {
   get,
   getModelSchemaRef,
 } from '@loopback/rest';
-import {
-  <%= sourceModelClassName %>,
+import {<%if (sourceModelClassName != targetModelClassName) { %>
+  <%= sourceModelClassName %>,<% } %>
   <%= targetModelClassName %>,
 } from '../models';
 import {<%= sourceRepositoryClassName %>} from '../repositories';

packages/cli/generators/relation/utils.generator.js

@@ -209,17 +209,20 @@ exports.addRequiredImports = function (sourceFile, imports) {
   }
 };
 
-exports.getRequiredImports = function (targetModel, relationType) {
-  return [
-    {
-      name: targetModel,
-      module: './' + utils.toFileName(targetModel) + '.model',
-    },
+exports.getRequiredImports = function (targetModel, relationType, sourceModel) {
+  const requiredImports = [
     {
       name: relationType,
       module: '@loopback/repository',
     },
   ];
+  if (sourceModel !== targetModel) {
+    requiredImports.push({
+      name: targetModel,
+      module: './' + utils.toFileName(targetModel) + '.model',
+    });
+  }
+  return requiredImports;
 };
 
 exports.addCurrentImport = function (sourceFile, currentImport) {

packages/cli/snapshots/integration/generators/relation.belongs-to.integration.snapshots.js

@@ -62,6 +62,29 @@ export class OrderRepository extends DefaultCrudRepository<
 `;
 
 
+exports[`lb4 relation checks generated source class repository for same table relation answers {"relationType":"belongsTo","sourceModel":"Employee","destinationModel":"Employee"} generates Employee repository file with different inputs 1`] = `
+import {inject, Getter} from '@loopback/core';
+import {DefaultCrudRepository, repository, BelongsToAccessor} from '@loopback/repository';
+import {DbDataSource} from '../datasources';
+import {Employee} from '../models';
+
+export class EmployeeRepository extends DefaultCrudRepository<
+  Employee,
+  typeof Employee.prototype.id
+> {
+
+  public readonly employee: BelongsToAccessor<Employee, typeof Employee.prototype.id>;
+
+  constructor(@inject('datasources.db') dataSource: DbDataSource, @repository.getter('EmployeeRepository') protected employeeRepositoryGetter: Getter<EmployeeRepository>,) {
+    super(Employee, dataSource);
+    this.employee = this.createBelongsToAccessorFor('employee', employeeRepositoryGetter,);
+    this.registerInclusionResolver('employee', this.employee.inclusionResolver);
+  }
+}
+
+`;
+
+
 exports[`lb4 relation checks if the controller file created  answers {"relationType":"belongsTo","sourceModel":"Order","destinationModel":"Customer","relationName":"my_customer"} checks controller content with belongsTo relation 1`] = `
 import {
   repository,
@@ -160,6 +183,18 @@ export * from './order-customer.controller';
 `;
 
 
+exports[`lb4 relation checks if the controller file created for same table relation answers {"relationType":"belongsTo","sourceModel":"Employee","destinationModel":"Employee"} checks controller content with belongsTo relation with same table 1`] = `
+export class EmployeeController {}
+
+`;
+
+
+exports[`lb4 relation checks if the controller file created for same table relation answers {"relationType":"belongsTo","sourceModel":"Employee","destinationModel":"Employee"} the new controller file added to index.ts file 1`] = `
+export * from './employee-employee.controller';
+
+`;
+
+
 exports[`lb4 relation generates model relation for existing property name verifies that a preexisting property will be overwritten 1`] = `
 import {Entity, model, property, belongsTo} from '@loopback/repository';
 import {Customer} from './customer.model';
@@ -245,3 +280,41 @@ export class Order extends Entity {
 }
 
 `;
+
+
+exports[`lb4 relation generates model relation with same table with default foreignKeyName verifies that a preexisting property will be overwritten 1`] = `
+import {Entity, model, property, belongsTo} from '@loopback/repository';
+
+@model()
+export class Employee extends Entity {
+  @property({
+    type: 'number',
+    id: true,
+    default: 0,
+  })
+  id?: number;
+
+  @property({
+    type: 'string',
+  })
+  firstName?: string;
+
+  @property({
+    type: 'string',
+  })
+  lastName?: string;
+
+  @property({
+    type: 'number',
+  })
+  reportsTo?: string;
+
+  @belongsTo(() => Employee, {name: 'reportsToEemployee'})
+  employeeId: number;
+
+  constructor(data?: Partial<Employee>) {
+    super(data);
+  }
+}
+
+`;

packages/cli/test/fixtures/relation/controllers/employee.controller.ts

@@ -0,0 +1 @@
+export class EmployeeController {}

packages/cli/test/fixtures/relation/index.js

@@ -147,6 +147,21 @@ const SourceEntries = {
     file: 'doctor-patient.controller.ts',
     content: readSourceFile('./controllers/doctor-patient.controller.ts'),
   },
+  EmployeeModel: {
+    path: MODEL_APP_PATH,
+    file: 'employee.model.ts',
+    content: readSourceFile('./models/employee.model.ts'),
+  },
+  EmployeeRepository: {
+    path: REPOSITORY_APP_PATH,
+    file: 'employee.repository.ts',
+    content: readSourceFile('./repositories/employee.repository.ts'),
+  },
+  EmployeeController: {
+    path: CONTROLLER_PATH,
+    file: 'employee.controller.ts',
+    content: readSourceFile('./controllers/employee.controller.ts'),
+  },
 };
 exports.SourceEntries = SourceEntries;
 
@@ -198,6 +213,7 @@ exports.SANDBOX_FILES = [
   SourceEntries.DoctorRepository,
   SourceEntries.PatientRepository,
   SourceEntries.AppointmentRepository,
+  SourceEntries.EmployeeRepository,
 
   SourceEntries.AccountModel,
   SourceEntries.CustomerModel,
@@ -208,6 +224,8 @@ exports.SANDBOX_FILES = [
   SourceEntries.PatientModel,
   SourceEntries.AppointmentModel,
   SourceEntries.DoctorPatientController,
+  SourceEntries.EmployeeModel,
+  SourceEntries.EmployeeController,
 ];
 
 exports.SANDBOX_FILES2 = [
@@ -219,6 +237,7 @@ exports.SANDBOX_FILES2 = [
   SourceEntries.DoctorRepository,
   SourceEntries.PatientRepository,
   SourceEntries.AppointmentRepository,
+  SourceEntries.EmployeeRepository,
 
   SourceEntries.CustomerModel,
   SourceEntries.CustomerModelWithInheritance,

packages/cli/test/fixtures/relation/models/employee.model.ts

@@ -0,0 +1,30 @@
+import {Entity, model, property} from '@loopback/repository';
+
+@model()
+export class Employee extends Entity {
+  @property({
+    type: 'number',
+    id: true,
+    default: 0,
+  })
+  id?: number;
+
+  @property({
+    type: 'string',
+  })
+  firstName?: string;
+
+  @property({
+    type: 'string',
+  })
+  lastName?: string;
+
+  @property({
+    type: 'number',
+  })
+  reportsTo?: string;
+
+  constructor(data?: Partial<Employee>) {
+    super(data);
+  }
+}

packages/cli/test/fixtures/relation/repositories/employee.repository.ts

@@ -0,0 +1,13 @@
+import {inject} from '@loopback/core';
+import {DefaultCrudRepository} from '@loopback/repository';
+import {DbDataSource} from '../datasources';
+import {Employee} from '../models';
+
+export class EmployeeRepository extends DefaultCrudRepository<
+  Employee,
+  typeof Employee.prototype.id
+> {
+  constructor(@inject('datasources.db') dataSource: DbDataSource) {
+    super(Employee, dataSource);
+  }
+}