feat(DTFS2-7121): create Companies House endpoint (#821)

.cspell.json

@@ -49,6 +49,7 @@
     "npmrc",
     "NVARCHAR",
     "osgb",
+    "pscs",
     "pino",
     "pinojs",
     "satify",

.env.sample

@@ -45,3 +45,9 @@ ORDNANCE_SURVEY_URL=https://api.os.uk
 ORDNANCE_SURVEY_KEY=
 ORDNANCE_SURVEY_MAX_REDIRECTS=
 ORDNANCE_SURVEY_TIMEOUT= # in milliseconds
+
+# COMPANIES HOUSE
+COMPANIES_HOUSE_URL=
+COMPANIES_HOUSE_KEY=
+COMPANIES_HOUSE_MAX_REDIRECTS=
+COMPANIES_HOUSE_TIMEOUT= # in milliseconds

CHANGELOG.md

@@ -26,7 +26,7 @@
 * **DTFS2-7052:** actioning PR comments ([e012eb4](https://github.com/UK-Export-Finance/mdm-api/commit/e012eb4a7912dcb254bfa0e7c2f5d2794f11ab58))
 * **DTFS2-7052:** actioning PR comments ([7d15b07](https://github.com/UK-Export-Finance/mdm-api/commit/7d15b07ef4126f99ffcf6189deac2b2391633edd))
 * **DTFS2-7052:** adding constants and examples ([a3d5433](https://github.com/UK-Export-Finance/mdm-api/commit/a3d54338610f50f4824d6c6eeffa50ebdb6e91a2))
-* **DTFS2-7052:** adding typescript include for json files, to satify lint. I added big examples to json files ([0b79772](https://github.com/UK-Export-Finance/mdm-api/commit/0b79772256a36fc8e5c9b38e3f67a0433984f2ab))
+* **DTFS2-7052:** adding typescript include for json files, to satisfy lint. I added big examples to json files ([0b79772](https://github.com/UK-Export-Finance/mdm-api/commit/0b79772256a36fc8e5c9b38e3f67a0433984f2ab))
 * **DTFS2-7052:** api-tests for geospatial/get-address-by-postcode ([c8cb1bc](https://github.com/UK-Export-Finance/mdm-api/commit/c8cb1bc98c72f3258f8bc9d498effdfe561ff45b))
 * **DTFS2-7052:** applying Oscars suggestions on my PR ([f68ac66](https://github.com/UK-Export-Finance/mdm-api/commit/f68ac66050ea3e0515378657f4893eb65f933ed4))
 * **DTFS2-7052:** change GET /geospatial/addresses/postcode?postcode= empty response from 200 to 404 ([33c9e65](https://github.com/UK-Export-Finance/mdm-api/commit/33c9e65961e67fdff36c854a7ae9f78c3c1ccd0c))

docker-compose.yml

@@ -37,6 +37,10 @@ services:
       ORDNANCE_SURVEY_KEY:
       ORDNANCE_SURVEY_MAX_REDIRECTS:
       ORDNANCE_SURVEY_TIMEOUT:
+      COMPANIES_HOUSE_URL:
+      COMPANIES_HOUSE_KEY:
+      COMPANIES_HOUSE_MAX_REDIRECTS:
+      COMPANIES_HOUSE_TIMEOUT:
       API_KEY:
     healthcheck:
       test: ["CMD", "curl", "-f", "http://localhost:${PORT}"]

src/config/companies-house.config.test.ts

@@ -0,0 +1,39 @@
+import { withEnvironmentVariableParsingUnitTests } from '@ukef-test/common-tests/environment-variable-parsing-unit-tests';
+
+import companiesHouseConfig, { CompaniesHouseConfig } from './companies-house.config';
+
+describe('companiesHouseConfig', () => {
+  const configDirectlyFromEnvironmentVariables: { configPropertyName: keyof CompaniesHouseConfig; environmentVariableName: string }[] = [
+    {
+      configPropertyName: 'baseUrl',
+      environmentVariableName: 'COMPANIES_HOUSE_URL',
+    },
+    {
+      configPropertyName: 'key',
+      environmentVariableName: 'COMPANIES_HOUSE_KEY',
+    },
+  ];
+
+  const configParsedAsIntFromEnvironmentVariablesWithDefault: {
+    configPropertyName: keyof CompaniesHouseConfig;
+    environmentVariableName: string;
+    defaultConfigValue: number;
+  }[] = [
+    {
+      configPropertyName: 'maxRedirects',
+      environmentVariableName: 'COMPANIES_HOUSE_MAX_REDIRECTS',
+      defaultConfigValue: 5,
+    },
+    {
+      configPropertyName: 'timeout',
+      environmentVariableName: 'COMPANIES_HOUSE_TIMEOUT',
+      defaultConfigValue: 30000,
+    },
+  ];
+
+  withEnvironmentVariableParsingUnitTests({
+    configDirectlyFromEnvironmentVariables,
+    configParsedAsIntFromEnvironmentVariablesWithDefault,
+    getConfig: () => companiesHouseConfig(),
+  });
+});

src/config/companies-house.config.ts

@@ -0,0 +1,20 @@
+import { registerAs } from '@nestjs/config';
+import { COMPANIES_HOUSE } from '@ukef/constants';
+import { getIntConfig } from '@ukef/helpers/get-int-config';
+
+export interface CompaniesHouseConfig {
+  baseUrl: string;
+  key: string;
+  maxRedirects: number;
+  timeout: number;
+}
+
+export default registerAs(
+  COMPANIES_HOUSE.CONFIG.KEY,
+  (): CompaniesHouseConfig => ({
+    baseUrl: process.env.COMPANIES_HOUSE_URL,
+    key: process.env.COMPANIES_HOUSE_KEY,
+    maxRedirects: getIntConfig(process.env.COMPANIES_HOUSE_MAX_REDIRECTS, 5),
+    timeout: getIntConfig(process.env.COMPANIES_HOUSE_TIMEOUT, 30000),
+  }),
+);

src/config/index.ts

@@ -1,7 +1,8 @@
 import AppConfig from './app.config';
+import CompaniesHouseConfig from './companies-house.config';
 import DatabaseConfig from './database.config';
 import DocConfig from './doc.config';
 import InformaticaConfig from './informatica.config';
 import OrdnanceSurveyConfig from './ordnance-survey.config';
 
-export default [AppConfig, DocConfig, DatabaseConfig, InformaticaConfig, OrdnanceSurveyConfig];
+export default [AppConfig, CompaniesHouseConfig, DocConfig, DatabaseConfig, InformaticaConfig, OrdnanceSurveyConfig];

src/constants/companies-house.constant.ts

@@ -0,0 +1,5 @@
+export const COMPANIES_HOUSE = {
+  CONFIG: {
+    KEY: 'companiesHouse',
+  },
+};

src/constants/companies.constant.ts

@@ -0,0 +1,10 @@
+export const COMPANIES = {
+  ENDPOINT_BASE_URL: '/api/v1/companies?registrationNumber=',
+  EXAMPLES: {
+    COMPANIES_HOUSE_REGISTRATION_NUMBER: '00000001',
+  },
+  REGEX: {
+    // This Companies House registration number regex was copied from the DTFS codebase.
+    COMPANIES_HOUSE_REGISTRATION_NUMBER: /^(([A-Z]{2}|[A-Z]\d|\d{2})(\d{5,6}|\d{4,5}[A-Z]))$/,
+  },
+};

src/constants/index.ts

@@ -10,9 +10,13 @@
  * 6. Strings to redact
  * 7. Strings locations to redact
  * 8. Module geospatial
+ * 9. Companies module
+ * 10. Companies House helper module
  */
 
 export * from './auth.constant';
+export * from './companies.constant';
+export * from './companies-house.constant';
 export * from './customers.constant';
 export * from './database-name.constant';
 export * from './date.constant';

src/helper-modules/companies-house/companies-house.module.ts

@@ -0,0 +1,27 @@
+import { Module } from '@nestjs/common';
+import { ConfigModule, ConfigService } from '@nestjs/config';
+import { CompaniesHouseConfig } from '@ukef/config/companies-house.config';
+import { COMPANIES_HOUSE } from '@ukef/constants';
+import { HttpModule } from '@ukef/modules/http/http.module';
+
+import { CompaniesHouseService } from './companies-house.service';
+
+@Module({
+  imports: [
+    HttpModule.registerAsync({
+      imports: [ConfigModule],
+      inject: [ConfigService],
+      useFactory: (configService: ConfigService) => {
+        const { baseUrl, maxRedirects, timeout } = configService.get<CompaniesHouseConfig>(COMPANIES_HOUSE.CONFIG.KEY);
+        return {
+          baseURL: baseUrl,
+          maxRedirects,
+          timeout,
+        };
+      },
+    }),
+  ],
+  providers: [CompaniesHouseService],
+  exports: [CompaniesHouseService],
+})
+export class CompaniesHouseModule {}

src/helper-modules/companies-house/companies-house.service.test.ts

@@ -0,0 +1,169 @@
+import { HttpService } from '@nestjs/axios';
+import { ConfigService } from '@nestjs/config';
+import { GetCompanyGenerator } from '@ukef-test/support/generator/get-company-generator';
+import { RandomValueGenerator } from '@ukef-test/support/generator/random-value-generator';
+import { AxiosError } from 'axios';
+import { resetAllWhenMocks, when } from 'jest-when';
+import { of, throwError } from 'rxjs';
+
+import { CompaniesHouseService } from './companies-house.service';
+import { CompaniesHouseException } from './exception/companies-house.exception';
+import { CompaniesHouseInvalidAuthorizationException } from './exception/companies-house-invalid-authorization.exception';
+import { CompaniesHouseMalformedAuthorizationHeaderException } from './exception/companies-house-malformed-authorization-header.exception';
+import { CompaniesHouseNotFoundException } from './exception/companies-house-not-found.exception';
+
+describe('CompaniesHouseService', () => {
+  let httpServiceGet: jest.Mock;
+  let configServiceGet: jest.Mock;
+  let service: CompaniesHouseService;
+
+  const valueGenerator = new RandomValueGenerator();
+
+  const testRegistrationNumber = '00000001';
+
+  const {
+    companiesHousePath,
+    getCompanyCompaniesHouseResponse,
+    getCompanyCompaniesHouseMalformedAuthorizationHeaderResponse,
+    getCompanyCompaniesHouseInvalidAuthorizationResponse,
+    getCompanyCompaniesHouseNotFoundResponse,
+  } = new GetCompanyGenerator(valueGenerator).generate({
+    numberToGenerate: 1,
+    registrationNumber: testRegistrationNumber,
+  });
+
+  const testKey = valueGenerator.string({ length: 40 });
+  const encodedTestKey = Buffer.from(testKey).toString('base64');
+
+  const expectedHttpServiceGetArguments: [string, object] = [
+    companiesHousePath,
+    {
+      headers: {
+        Authorization: `Basic ${encodedTestKey}`,
+      },
+    },
+  ];
+
+  const expectedHttpServiceGetResponse = of({
+    data: getCompanyCompaniesHouseResponse,
+    status: 200,
+    statusText: 'OK',
+    config: undefined,
+    headers: undefined,
+  });
+
+  beforeAll(() => {
+    const httpService = new HttpService();
+    httpServiceGet = jest.fn();
+    httpService.get = httpServiceGet;
+
+    const configService = new ConfigService();
+    configServiceGet = jest.fn().mockReturnValue({ key: testKey });
+    configService.get = configServiceGet;
+
+    service = new CompaniesHouseService(httpService, configService);
+  });
+
+  beforeEach(() => {
+    resetAllWhenMocks();
+  });
+
+  describe('getCompanyByRegistrationNumber', () => {
+    it('calls the Companies House API with the correct arguments', async () => {
+      when(httpServiceGet)
+        .calledWith(...expectedHttpServiceGetArguments)
+        .mockReturnValueOnce(expectedHttpServiceGetResponse);
+
+      await service.getCompanyByRegistrationNumber(testRegistrationNumber);
+
+      expect(httpServiceGet).toHaveBeenCalledTimes(1);
+      expect(httpServiceGet).toHaveBeenCalledWith(...expectedHttpServiceGetArguments);
+    });
+
+    it('returns the results when the Companies House API returns a 200 response with results', async () => {
+      when(httpServiceGet)
+        .calledWith(...expectedHttpServiceGetArguments)
+        .mockReturnValueOnce(expectedHttpServiceGetResponse);
+
+      const response = await service.getCompanyByRegistrationNumber(testRegistrationNumber);
+
+      expect(response).toBe(getCompanyCompaniesHouseResponse);
+    });
+
+    it(`throws a CompaniesHouseMalformedAuthorizationHeaderException when the Companies House API returns a 400 response containing the error string 'Invalid Authorization header'`, async () => {
+      const axiosError = new AxiosError();
+      axiosError.response = {
+        data: getCompanyCompaniesHouseMalformedAuthorizationHeaderResponse,
+        status: 400,
+        statusText: 'Bad Request',
+        config: undefined,
+        headers: undefined,
+      };
+
+      when(httpServiceGet)
+        .calledWith(...expectedHttpServiceGetArguments)
+        .mockReturnValueOnce(throwError(() => axiosError));
+
+      const getCompanyPromise = service.getCompanyByRegistrationNumber(testRegistrationNumber);
+
+      await expect(getCompanyPromise).rejects.toBeInstanceOf(CompaniesHouseMalformedAuthorizationHeaderException);
+      await expect(getCompanyPromise).rejects.toThrow(`Invalid 'Authorization' header. Check that your 'Authorization' header is well-formed.`);
+      await expect(getCompanyPromise).rejects.toHaveProperty('innerError', axiosError);
+    });
+
+    it(`throws a CompaniesHouseInvalidAuthorizationException when the Companies House API returns a 401 response containing the error string 'Invalid Authorization'`, async () => {
+      const axiosError = new AxiosError();
+      axiosError.response = {
+        data: getCompanyCompaniesHouseInvalidAuthorizationResponse,
+        status: 401,
+        statusText: 'Unauthorized',
+        config: undefined,
+        headers: undefined,
+      };
+
+      when(httpServiceGet)
+        .calledWith(...expectedHttpServiceGetArguments)
+        .mockReturnValueOnce(throwError(() => axiosError));
+
+      const getCompanyPromise = service.getCompanyByRegistrationNumber(testRegistrationNumber);
+
+      await expect(getCompanyPromise).rejects.toBeInstanceOf(CompaniesHouseInvalidAuthorizationException);
+      await expect(getCompanyPromise).rejects.toThrow('Invalid authorization. Check your Companies House API key.');
+      await expect(getCompanyPromise).rejects.toHaveProperty('innerError', axiosError);
+    });
+
+    it(`throws a CompaniesHouseNotFoundException when the Companies House API returns a 404 response containing the error string 'company-profile-not-found'`, async () => {
+      const axiosError = new AxiosError();
+      axiosError.response = {
+        data: getCompanyCompaniesHouseNotFoundResponse,
+        status: 404,
+        statusText: 'Not Found',
+        config: undefined,
+        headers: undefined,
+      };
+
+      when(httpServiceGet)
+        .calledWith(...expectedHttpServiceGetArguments)
+        .mockReturnValueOnce(throwError(() => axiosError));
+
+      const getCompanyPromise = service.getCompanyByRegistrationNumber(testRegistrationNumber);
+
+      await expect(getCompanyPromise).rejects.toBeInstanceOf(CompaniesHouseNotFoundException);
+      await expect(getCompanyPromise).rejects.toThrow(`Company with registration number ${testRegistrationNumber} was not found.`);
+      await expect(getCompanyPromise).rejects.toHaveProperty('innerError', axiosError);
+    });
+
+    it('throws a CompaniesHouseException if the Companies House API returns an unknown error response', async () => {
+      const axiosError = new AxiosError();
+      when(httpServiceGet)
+        .calledWith(...expectedHttpServiceGetArguments)
+        .mockReturnValueOnce(throwError(() => axiosError));
+
+      const getCompanyPromise = service.getCompanyByRegistrationNumber(testRegistrationNumber);
+
+      await expect(getCompanyPromise).rejects.toBeInstanceOf(CompaniesHouseException);
+      await expect(getCompanyPromise).rejects.toThrow('Failed to get response from Companies House API.');
+      await expect(getCompanyPromise).rejects.toHaveProperty('innerError', axiosError);
+    });
+  });
+});

src/helper-modules/companies-house/companies-house.service.ts

@@ -0,0 +1,48 @@
+import { HttpService } from '@nestjs/axios';
+import { Injectable } from '@nestjs/common';
+import { ConfigService } from '@nestjs/config';
+import { CompaniesHouseConfig } from '@ukef/config/companies-house.config';
+import { COMPANIES_HOUSE } from '@ukef/constants';
+import { HttpClient } from '@ukef/modules/http/http.client';
+
+import { GetCompanyCompaniesHouseResponse } from './dto/get-company-companies-house-response.dto';
+import {
+  getCompanyInvalidAuthorizationKnownCompaniesHouseError,
+  getCompanyMalformedAuthorizationHeaderKnownCompaniesHouseError,
+  getCompanyNotFoundKnownCompaniesHouseError,
+} from './known-errors';
+import { createWrapCompaniesHouseHttpGetErrorCallback } from './wrap-companies-house-http-error-callback';
+
+@Injectable()
+export class CompaniesHouseService {
+  private readonly httpClient: HttpClient;
+  private readonly key: string;
+
+  constructor(httpService: HttpService, configService: ConfigService) {
+    this.httpClient = new HttpClient(httpService);
+    const { key } = configService.get<CompaniesHouseConfig>(COMPANIES_HOUSE.CONFIG.KEY);
+    this.key = key;
+  }
+
+  async getCompanyByRegistrationNumber(registrationNumber: string): Promise<GetCompanyCompaniesHouseResponse> {
+    const path = `/company/${registrationNumber}`;
+    const encodedKey = Buffer.from(this.key).toString('base64');
+
+    const { data } = await this.httpClient.get<GetCompanyCompaniesHouseResponse>({
+      path,
+      headers: {
+        Authorization: `Basic ${encodedKey}`,
+      },
+      onError: createWrapCompaniesHouseHttpGetErrorCallback({
+        messageForUnknownError: 'Failed to get response from Companies House API.',
+        knownErrors: [
+          getCompanyMalformedAuthorizationHeaderKnownCompaniesHouseError(),
+          getCompanyInvalidAuthorizationKnownCompaniesHouseError(),
+          getCompanyNotFoundKnownCompaniesHouseError(registrationNumber),
+        ],
+      }),
+    });
+
+    return data;
+  }
+}

src/helper-modules/companies-house/dto/get-company-companies-house-error-response.dto.ts

@@ -0,0 +1,4 @@
+export type GetCompanyCompaniesHouseErrorResponse = {
+  error: string;
+  type: string;
+};

src/helper-modules/companies-house/dto/get-company-companies-house-multiple-error-response.dto.ts

@@ -0,0 +1,5 @@
+import { GetCompanyCompaniesHouseErrorResponse } from './get-company-companies-house-error-response.dto';
+
+export type GetCompanyCompaniesHouseMultipleErrorResponse = {
+  errors: GetCompanyCompaniesHouseErrorResponse[];
+};