fix: export EggAppConfig type let plugin can override it (#286)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **Type Safety Improvements**
	- Enhanced type definitions for application configuration
	- Centralized type management across modules
	- Introduced more precise type checking for configuration objects

- **Code Structure**
	- Refactored type imports and exports
	- Updated case style handling with new enum
	- Simplified type management in loader components

- **Testing**
	- Added type exposure tests
	- Updated test configurations to reflect new type structures

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: fengmk2

src/egg.ts

@@ -18,6 +18,7 @@ import type { Fun } from './utils/index.js';
 import { Lifecycle } from './lifecycle.js';
 import { EggLoader } from './loader/egg_loader.js';
 import utils from './utils/index.js';
+import { EggAppConfig } from './types.js';
 
 const debug = debuglog('@eggjs/core/egg');
 
@@ -247,8 +248,8 @@ export class EggCore extends KoaApplication {
    * @member {Config}
    * @since 1.0.0
    */
-  get config() {
-    return this.loader ? this.loader.config : {};
+  get config(): EggAppConfig {
+    return this.loader ? this.loader.config : {} as EggAppConfig;
   }
 
   /**

src/index.ts

@@ -10,3 +10,4 @@ export * from './loader/file_loader.js';
 export * from './loader/context_loader.js';
 export * from './utils/sequencify.js';
 export * from './utils/timing.js';
+export type * from './types.js';

src/loader/egg_loader.ts

@@ -10,7 +10,7 @@ import { extend } from 'extend2';
 import { Request, Response, Application, Context as KoaContext } from '@eggjs/koa';
 import { pathMatching, type PathMatchingOptions } from 'egg-path-matching';
 import { now, diff } from 'performance-ms';
-import { FULLPATH, FileLoader, FileLoaderOptions } from './file_loader.js';
+import { CaseStyle, FULLPATH, FileLoader, FileLoaderOptions } from './file_loader.js';
 import { ContextLoader, ContextLoaderOptions } from './context_loader.js';
 import utils, { Fun } from '../utils/index.js';
 import sequencify from '../utils/sequencify.js';
@@ -19,6 +19,7 @@ import type {
   Context, EggCore, MiddlewareFunc,
 } from '../egg.js';
 import type { BaseContextClass } from '../base_context_class.js';
+import type { EggAppConfig, EggAppInfo, EggPluginInfo } from '../types.js';
 
 const debug = debuglog('@eggjs/core/loader/egg_loader');
 
@@ -29,44 +30,6 @@ const originalPrototypes: Record<string, any> = {
   application: Application.prototype,
 };
 
-export interface EggAppInfo {
-  /** package.json */
-  pkg: Record<string, any>;
-  /** the application name from package.json */
-  name: string;
-  /** current directory of application */
-  baseDir: string;
-  /** equals to serverEnv */
-  env: string;
-  /** equals to serverScope */
-  scope: string;
-  /** home directory of the OS */
-  HOME: string;
-  /** baseDir when local and unittest, HOME when other environment */
-  root: string;
-}
-
-export interface EggPluginInfo {
-  /** the plugin name, it can be used in `dep` */
-  name: string;
-  /** the package name of plugin */
-  package?: string;
-  version?: string;
-  /** whether enabled */
-  enable: boolean;
-  implicitEnable?: boolean;
-  /** the directory of the plugin package */
-  path?: string;
-  /** the dependent plugins, you can use the plugin name */
-  dependencies: string[];
-  /** the optional dependent plugins. */
-  optionalDependencies: string[];
-  dependents?: string[];
-  /** specify the serverEnv that only enable the plugin in it */
-  env: string[];
-  /** the file plugin config in. */
-  from: string;
-}
 
 export interface EggLoaderOptions {
   /** server env */
@@ -845,7 +808,7 @@ export class EggLoader {
 
   /** start Config loader */
   configMeta: Record<string, any>;
-  config: Record<string, any>;
+  config: EggAppConfig;
 
   /**
    * Load config/config.js
@@ -859,7 +822,10 @@ export class EggLoader {
     this.timing.start('Load Config');
     this.configMeta = {};
 
-    const target: Record<string, any> = {};
+    const target: EggAppConfig = {
+      middleware: [],
+      coreMiddleware: [],
+    };
 
     // Load Application config first
     const appConfig = await this.#preloadAppConfig();
@@ -1208,7 +1174,7 @@ export class EggLoader {
     const servicePaths = this.getLoadUnits().map(unit => path.join(unit.path, 'app/service'));
     options = {
       call: true,
-      caseStyle: 'lower',
+      caseStyle: CaseStyle.lower,
       fieldClass: 'serviceClasses',
       directory: servicePaths,
       ...options,
@@ -1248,7 +1214,7 @@ export class EggLoader {
     opt = {
       call: false,
       override: true,
-      caseStyle: 'lower',
+      caseStyle: CaseStyle.lower,
       directory: middlewarePaths,
       ...opt,
     };
@@ -1323,7 +1289,7 @@ export class EggLoader {
     this.timing.start('Load Controller');
     const controllerBase = path.join(this.options.baseDir, 'app/controller');
     opt = {
-      caseStyle: 'lower',
+      caseStyle: CaseStyle.lower,
       directory: controllerBase,
       initializer: (obj, opt) => {
         // return class if it exports a function
@@ -1403,7 +1369,7 @@ export class EggLoader {
         case 'ctx': {
           assert(!(property in this.app.context), `customLoader should not override ctx.${property}`);
           const options = {
-            caseStyle: 'lower',
+            caseStyle: CaseStyle.lower,
             fieldClass: `${property}Classes`,
             ...loaderConfig,
             directory,
@@ -1414,7 +1380,7 @@ export class EggLoader {
         case 'app': {
           assert(!(property in this.app), `customLoader should not override app.${property}`);
           const options = {
-            caseStyle: 'lower',
+            caseStyle: CaseStyle.lower,
             initializer: (Clazz: unknown) => {
               return isClass(Clazz) ? new Clazz(this.app) : Clazz;
             },
@@ -1533,10 +1499,11 @@ export class EggLoader {
    * @param {Object} options - see {@link FileLoader}
    * @since 1.0.0
    */
-  async loadToApp(directory: string | string[], property: string | symbol, options?: FileLoaderOptions) {
+  async loadToApp(directory: string | string[], property: string | symbol,
+    options?: Omit<FileLoaderOptions, 'inject' | 'target'>) {
     const target = {};
     Reflect.set(this.app, property, target);
-    options = {
+    const loadOptions: FileLoaderOptions = {
       ...options,
       directory: options?.directory ?? directory,
       target,
@@ -1545,7 +1512,7 @@ export class EggLoader {
 
     const timingKey = `Load "${String(property)}" to Application`;
     this.timing.start(timingKey);
-    await new FileLoader(options).load();
+    await new FileLoader(loadOptions).load();
     this.timing.end(timingKey);
   }
 
@@ -1556,8 +1523,9 @@ export class EggLoader {
    * @param {Object} options - see {@link ContextLoader}
    * @since 1.0.0
    */
-  async loadToContext(directory: string | string[], property: string | symbol, options?: ContextLoaderOptions) {
-    options = {
+  async loadToContext(directory: string | string[], property: string | symbol,
+    options?: Omit<ContextLoaderOptions, 'inject' | 'property'>) {
+    const loadOptions: ContextLoaderOptions = {
       ...options,
       directory: options?.directory || directory,
       property,
@@ -1566,7 +1534,7 @@ export class EggLoader {
 
     const timingKey = `Load "${String(property)}" to Context`;
     this.timing.start(timingKey);
-    await new ContextLoader(options).load();
+    await new ContextLoader(loadOptions).load();
     this.timing.end(timingKey);
   }
 

src/loader/file_loader.ts

@@ -11,7 +11,12 @@ const debug = debuglog('@eggjs/core/file_loader');
 export const FULLPATH = Symbol('EGG_LOADER_ITEM_FULLPATH');
 export const EXPORTS = Symbol('EGG_LOADER_ITEM_EXPORTS');
 
-export type CaseStyle = 'camel' | 'lower' | 'upper';
+export enum CaseStyle {
+  camel = 'camel',
+  lower = 'lower',
+  upper = 'upper',
+}
+
 export type CaseStyleFunction = (filepath: string) => string[];
 export type FileLoaderInitializer = (exports: unknown, options: { path: string; pathName: string }) => unknown;
 export type FileLoaderFilter = (exports: unknown) => boolean;
@@ -79,7 +84,7 @@ export class FileLoader {
     assert(options.directory, 'options.directory is required');
     assert(options.target, 'options.target is required');
     this.options = {
-      caseStyle: 'camel',
+      caseStyle: CaseStyle.camel,
       call: true,
       override: false,
       ...options,
@@ -88,7 +93,7 @@ export class FileLoader {
     // compatible old options _lowercaseFirst_
     if (this.options.lowercaseFirst === true) {
       utils.deprecated('lowercaseFirst is deprecated, use caseStyle instead');
-      this.options.caseStyle = 'lower';
+      this.options.caseStyle = CaseStyle.lower;
     }
   }
 

src/types.ts

@@ -0,0 +1,56 @@
+export interface EggAppInfo {
+  /** package.json */
+  pkg: Record<string, any>;
+  /** the application name from package.json */
+  name: string;
+  /** current directory of application */
+  baseDir: string;
+  /** equals to serverEnv */
+  env: string;
+  /** equals to serverScope */
+  scope: string;
+  /** home directory of the OS */
+  HOME: string;
+  /** baseDir when local and unittest, HOME when other environment */
+  root: string;
+}
+
+export interface EggPluginInfo {
+  /** the plugin name, it can be used in `dep` */
+  name: string;
+  /** the package name of plugin */
+  package?: string;
+  version?: string;
+  /** whether enabled */
+  enable: boolean;
+  implicitEnable?: boolean;
+  /** the directory of the plugin package */
+  path?: string;
+  /** the dependent plugins, you can use the plugin name */
+  dependencies: string[];
+  /** the optional dependent plugins. */
+  optionalDependencies: string[];
+  dependents?: string[];
+  /** specify the serverEnv that only enable the plugin in it */
+  env: string[];
+  /** the file plugin config in. */
+  from: string;
+}
+
+export interface CustomLoaderConfigItem {
+  /** the directory of the custom loader */
+  directory: string;
+  /** the inject object, it can be app or ctx */
+  inject: string;
+  /** whether load unit files */
+  loadunit?: boolean;
+}
+
+export interface EggAppConfig extends Record<string, any> {
+  coreMiddleware: string[];
+  middleware: string[];
+  customLoader?: Record<string, CustomLoaderConfigItem>;
+  controller?: {
+    supportParams?: boolean;
+  };
+}

test/index.test.ts

@@ -1,5 +1,6 @@
 import { strict as assert } from 'node:assert';
 import * as EggCore from '../src/index.js';
+import type { EggAppConfig } from '../src/index.js';
 
 describe('test/index.test.ts', () => {
   it('should expose properties', () => {
@@ -10,6 +11,7 @@ describe('test/index.test.ts', () => {
     console.log(Object.keys(EggCore));
     assert.deepEqual(Object.keys(EggCore), [
       'BaseContextClass',
+      'CaseStyle',
       'ClassLoader',
       'Context',
       'ContextLoader',
@@ -31,4 +33,13 @@ describe('test/index.test.ts', () => {
       'utils',
     ]);
   });
+
+  it('should expose types', () => {
+    const config = {
+      coreMiddleware: [],
+      middleware: [],
+    } as EggAppConfig;
+    assert(config.middleware);
+    assert(config.coreMiddleware);
+  });
 });

test/loader/file_loader.test.ts

@@ -2,7 +2,7 @@ import { strict as assert } from 'node:assert';
 import path from 'node:path';
 import { isClass } from 'is-type-of';
 import yaml from 'js-yaml';
-import { FileLoader } from '../../src/loader/file_loader.js';
+import { FileLoader, CaseStyle } from '../../src/loader/file_loader.js';
 import { getFilepath } from '../helper.js';
 
 const dirBase = getFilepath('load_dirs');
@@ -275,7 +275,7 @@ describe('test/loader/file_loader.test.ts', () => {
       await new FileLoader({
         directory: path.join(dirBase, 'camelize'),
         target,
-        caseStyle: 'upper',
+        caseStyle: CaseStyle.upper,
       }).load();
 
       assert(target.FooBar1);
@@ -289,7 +289,7 @@ describe('test/loader/file_loader.test.ts', () => {
       await new FileLoader({
         directory: path.join(dirBase, 'camelize'),
         target,
-        caseStyle: 'camel',
+        caseStyle: CaseStyle.camel,
       }).load();
 
       assert(target.fooBar1);
@@ -303,7 +303,7 @@ describe('test/loader/file_loader.test.ts', () => {
       await new FileLoader({
         directory: path.join(dirBase, 'camelize'),
         target,
-        caseStyle: 'lower',
+        caseStyle: CaseStyle.lower,
       }).load();
 
       assert(target.fooBar1);
@@ -349,7 +349,7 @@ describe('test/loader/file_loader.test.ts', () => {
       await new FileLoader({
         directory: path.join(dirBase, 'camelize'),
         target,
-        caseStyle: 'upper',
+        caseStyle: CaseStyle.upper,
         lowercaseFirst: true,
       }).load();
 

test/loader/mixin/load_controller.test.ts

@@ -379,7 +379,7 @@ describe('test/loader/mixin/load_controller.test.ts', () => {
     });
 
     it('should support parameter', async () => {
-      assert.equal(app.config.controller.supportParams, true);
+      assert.equal(app.config.controller!.supportParams, true);
       const ctx = { app };
       const args = [ 1, 2, 3 ];
       let r = await app.controller.generatorFunction.call(ctx, ...args);