Feature: refactor to IoC (inverse of control) pattern in serve package

[kokokuo]

Description

Rebase develop and adapt IoC pattern to inject dependencies by InversifyJS for the serve package. The PR includes the previous implemented and approved features from PRs:

• Feature: Implementing restful route generator and api server according to api schema #8
• Feature: Implementing data query builder #11
• Feature: Implementing pagination strategy and data source driver interface #12
• Feature: Provide Validator Loader to load built-in and user-defined path validators #14
• Feature: Implementing built-in middleware and middleware loader #17

After rebased, and Refactor to the IoC pattern, there are some things changed:

all packages

• add setupFilesAfterEnv in jest.config.ts and import reflect-metadata first for jest testing could collect IoC inject in each package.

In the core package

• refactor the defaultImport logistic to support importing multiple extensions and add mergedModules to merge multiple extension modules to the one module object.

/** dynamic import default module.  e.g: ['extensionsA', 'extensionsB']  */
export const defaultImport = async <T = any>(
  ...foldersOrFiles: Array<string>
) => {
  const modules = [] as Array<T>;
  for (const folderOrFile of foldersOrFiles) {
    const module = await import(folderOrFile);
    // if module default is undefined, then set the all export context to default
    const imported = module.default ? (module.default as T) : (module as T);
    modules.push(imported);
  }
  return modules;
};

/** merged multiple properties of each modules to the one module object */
export const mergedModules = async <T = any>(modules: Array<T>) => {
    const module = modules.reduce((merged: ModuleProperties, current: ModuleProperties, _) => {
      for (const extension of Object.keys(current)) {
        // if current extension property has been existed in merged module, concat it.
        if (extension in merged)
          merged[extension] = [...merged[extension], ...current[extension]];
        // if extension not in merged module, add new extension property
        else merged[extension] = current[extension];
      }
      return merged;
    },
    {} as T);

• create pagination.ts in core package to define pagination model and move data-query folder and data-source folder to core package ( also include test cases ), because build and serve also need them.
• update the executorModule to bind the real data query builder and update the test case for the test compiler.

export const executorModule = () =>
  new ContainerModule((bind) => {
    /**
     * TODO: bind mock data source, need to update after real data source implemented.
     */
    bind<IDataSource>(TYPES.IDataSource).toConstantValue(new MockDataSource());

    bind<Executor>(TYPES.Executor).toDynamicValue((context) => {
      const dataSource = context.container.get<MockDataSource>(
        TYPES.IDataSource
      );
      return {
        createBuilder: async (query: string) =>
          new DataQueryBuilder({ statement: query, dataSource }),
      };
    });
  });

In the serve package

• refactor ServeConfig for inheriting CoreOptions and create AppConfig for middleware and VulcanApplication.

import { ICoreOptions } from '@vulcan/core';
import { APIProviderType } from '@vulcan/serve/route';
import { MiddlewareConfig } from './middlewareConfig';

// The serve package config
export interface ServeConfig extends ICoreOptions {
  /** The middleware config options */
  middlewares?: MiddlewareConfig;
  /* The API types would like to build */
  types: Array<APIProviderType>;
}

export type AppConfig = Omit<ServeConfig, 'artifact' | 'template' | 'types'>;

• fix loadExtensions function to merged modules after defaultImport response updated.

export interface ExtensionModule {
 middlewares?: ClassType<BaseRouteMiddleware>[];
}
export const loadExtensions = async (extensions?: SourceOfExtensions) => {
 // if extensions setup, load middlewares classes in the extensions
 if (extensions) {
   // import extension which user customized
   const modules = await defaultImport<ExtensionModule>(...extensions);
   const module = await mergedModules<ExtensionModule>(modules);
   // return middleware classes in folder
   return module.middlewares || [];
 }
 return [];
};

• refactor VulcanApplication for focusing on building middleware and route and create VulcanServer for running the server.

export class VulcanServer {
  private config: ServeConfig;
  private container: Container;
  private server?: http.Server;
  private schemas: Array<APISchema>;
  constructor(config: ServeConfig, schemas: Array<APISchema>) {
    this.config = config;
    this.schemas = schemas;
    this.container = new Container();
  }
  public async start(port = 3000) {
    if (this.server)
      throw new Error('Server has created, please close it first.');

    // Get generator
    await this.container.load(this.config);
    const generator = this.container.get<RouteGenerator>(TYPES.RouteGenerator);

    // Create application
    const app = new VulcanApplication(omit(this.config, 'template'), generator);
    await app.buildMiddleware();
    await app.buildRoutes(this.schemas, this.config.types);
    // Run server
    this.server = http.createServer(app.getHandler()).listen(port);
  }
  public async close() {
    if (this.server) this.server.close();
    this.container.unload();
  }
}

How To Test / Expected Results

For the test result, please see the below test cases that passed the unit test:

The core package

The build package

The serve package

Commit Message

Because the PR included rebased commits, here is only the list refactor to IoC commits:

• a9a1633 - make validator loader by IoC, refactor default module import logistic, add required validator to make test case work.
  • Rename folder from data-type-validators to built-in-validators.
    • Add required validator test cases
    • refactor validateData method to any in IValidator.
    • refactor validateData type for IntegerTypeValidator, RequiredValidator.
    • add extensions property in ICoreOptions to collect different extension modules name / folder path.
    • add SourceOfExtensions TYPE and refactor to inject extensions in ValidatorLoader.
    • refactor defaultImport to import multiple modules
    • add mergedModules to merge multiple extension modules to the one module object.
    • change to container load and enhance test cases of validator loader to check to import multiple modules.
    • add setupFilesAfterEnv in jest.config.ts import reflect-metadata first for jest testing could collect IoC inject decorators.decorators.
• 60edba9 - add setupFilesAfterEnv in jest.config.js, support extensions property in test cases.
• ac21198 - move data query builder and data source modules to core package.
  • create pagination.ts in core package to define the pagination model.
  • move data-query folder and data-source folder to core package.
• 90a82fa - make the data query builder and data source created by the IoC container.
  • update the execute module to bind the real data query builder.
  • update data query builder to return by IDataQueryBuilder.
  • update test case for test compiler.
• 579249f - refactor the serve package by IoC pattern.
  • refactor import way from fs/promises to { promises as fs } from 'fs' for making jest debug work.
  • fix the ValidatorLoader inject optional field in the constructor.
  • add TYPES, "Container" and load routeGeneratorModule.
  • refactor ServeConfig for inheriting CoreOptions and create AppConfig for middleware and VulcanApplication.
  • fix loadExtensions function to merged modules after defaultImport response updated.
  • refactor VulcanApplication for focusing on building middleware and route.
  • create VulcanServer for running the server.
  • update all test cases for supporting IoC pattern in serve package.

• 6a195f3 - feat(core, serve): fix the load extension module for throwing duplicate properties in multiple modules.
  • remove the logistic for throwing duplicate property in multiple modules in mergedModules.
  • add the checkSameNameValidator logistic for checking duplicate key name after creating validator by class from the module.
  • add the logistic for checking duplicate key names after creating middleware by class from module in VulcanApplication.
  • add more test cases for the validator loader to check load extensions.
  • move the setupFilesAfterEnv setting to jest.preset.ts.

[kokokuo]

rebase finished, start to refactor for using IoC pattern.

[kokokuo]

Update all serve packages to use IoC Pattern and create by IoC Container, all test cases passed (core, build, serve).

[oscar60310]

LGTM besides some questions about IoC.

[oscar60310]

NIT: I'll call getLocal multiple times, it appeared to me that we have imported the code of validators to memory, we just initialized them here. But with your code, we seem to import the code via .load function, will it cause performance issues?

[kokokuo]

Thanks @oscar60310 for reviewing and suggesting, after discussing in the morning, this part will keep and do it after a meeting discussion.

[oscar60310]

I remember we've discussed this, but I still have some questions:
Why did we use the leading "I" for the identifiers? It makes sense to use "I" to indicate the difference between interface and class like this:

interface Ixxxx {}
class xxxx implement Ixxxx {}

But here we don't care about what type we'll get, we just want an instance, it might confuse us if we don't use a consistent naming rule, that is, TYPE.Executor but TYPE.IDataSource.

Did you want to let the identifiers have the same name as their interface?

[kokokuo]

Thanks @oscar60310 for reviewing and suggesting, after discussion, we keep the TYPES no need to add prefix I and make the interface add the prefix I for those needed to be implemented by the class.

[oscar60310]

NIT: How about creating an Executor class instead of using a pure object?

[kokokuo]

Thanks @oscar60310 for reviewing, I have created a pure class QueryExecutor to do it.

[kokokuo]

Hi @oscar60310 all suggestion has been fixed, please check it, thanks too much.

[oscar60310]

LGTM 👍