使用 Typescript 在 Nodejs 中导入语句在编译后不会使用绝对路径解析

Question

我正在尝试使用 Typescript 在 NodeJs 中编写服务器。我已经安装了这些devDependencies：

    "@types/config": "^0.0.38",
    "@types/express": "^4.17.12",
    "@types/jsonwebtoken": "^8.5.1",
    "@types/lodash": "^4.14.170",
    "@types/morgan": "^1.9.2",   

    "nodemon": "^2.0.7",
    "tslint": "^6.1.3",
    "typescript": "^4.3.2"

我的tsconfig.json是这样的：

{
  "compilerOptions": {
    /* Visit https://aka.ms/tsconfig.json to read more about this file */

    /* Basic Options */
    // "incremental": true,                         /* Enable incremental compilation */
    "target": "es5",                                /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019', 'ES2020', 'ES2021', or 'ESNEXT'. */
    "module": "commonjs",                           /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', 'es2020', or 'ESNext'. */
    // "lib": [],                                   /* Specify library files to be included in the compilation. */
    // "allowJs": true,                             /* Allow javascript files to be compiled. */
    // "checkJs": true,                             /* Report errors in .js files. */
    // "jsx": "preserve",                           /* Specify JSX code generation: 'preserve', 'react-native', 'react', 'react-jsx' or 'react-jsxdev'. */
    // "declaration": true,                         /* Generates corresponding '.d.ts' file. */
    // "declarationMap": true,                      /* Generates a sourcemap for each corresponding '.d.ts' file. */
    "sourceMap": true,                           /* Generates corresponding '.map' file. */
    // "outFile": "./",                             /* Concatenate and emit output to single file. */
    "outDir": "./dist/",                              /* Redirect output structure to the directory. */
    "rootDir": "./src",                          /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
    // "composite": true,                           /* Enable project compilation */
    // "tsBuildInfoFile": "./",                     /* Specify file to store incremental compilation information */
    // "removeComments": true,                      /* Do not emit comments to output. */
    // "noEmit": true,                              /* Do not emit outputs. */
    // "importHelpers": true,                       /* Import emit helpers from 'tslib'. */
    // "downlevelIteration": true,                  /* Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. */
    // "isolatedModules": true,                     /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */

    /* Strict Type-Checking Options */
    // "strict": true,                                 /* Enable all strict type-checking options. */
    // "noImplicitAny": true,                       /* Raise error on expressions and declarations with an implied 'any' type. */
    // "strictNullChecks": true,                    /* Enable strict null checks. */
    // "strictFunctionTypes": true,                 /* Enable strict checking of function types. */
    // "strictBindCallApply": true,                 /* Enable strict 'bind', 'call', and 'apply' methods on functions. */
    // "strictPropertyInitialization": true,        /* Enable strict checking of property initialization in classes. */
    // "noImplicitThis": true,                      /* Raise error on 'this' expressions with an implied 'any' type. */
    // "alwaysStrict": true,                        /* Parse in strict mode and emit "use strict" for each source file. */

    /* Additional Checks */
    // "noUnusedLocals": true,                      /* Report errors on unused locals. */
    // "noUnusedParameters": true,                  /* Report errors on unused parameters. */
    // "noImplicitReturns": true,                   /* Report error when not all code paths in function return a value. */
    // "noFallthroughCasesInSwitch": true,          /* Report errors for fallthrough cases in switch statement. */
    // "noUncheckedIndexedAccess": true,            /* Include 'undefined' in index signature results */
    // "noImplicitOverride": true,                  /* Ensure overriding members in derived classes are marked with an 'override' modifier. */
    // "noPropertyAccessFromIndexSignature": true,  /* Require undeclared properties from index signatures to use element accesses. */

    /* Module Resolution Options */
    "moduleResolution": "node",                  /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */
    "baseUrl": "./src",                             /* Base directory to resolve non-absolute module names. */
    // "paths": {},                                 /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */
    // "rootDirs": [],                              /* List of root folders whose combined content represents the structure of the project at runtime. */
    // "typeRoots": [],                             /* List of folders to include type definitions from. */
    // "types": [],                                 /* Type declaration files to be included in compilation. */
    // "allowSyntheticDefaultImports": true,        /* Allow default imports from modules with no default export. This does not affect code emit, just typechecking. */
    "esModuleInterop": true,                        /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
    // "preserveSymlinks": true,                    /* Do not resolve the real path of symlinks. */
    // "allowUmdGlobalAccess": true,                /* Allow accessing UMD globals from modules. */

    /* Source Map Options */
    // "sourceRoot": "",                            /* Specify the location where debugger should locate TypeScript files instead of source locations. */
    // "mapRoot": "",                               /* Specify the location where debugger should locate map files instead of generated locations. */
    // "inlineSourceMap": true,                     /* Emit a single file with source maps instead of having a separate file. */
    // "inlineSources": true,                       /* Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set. */

    /* Experimental Options */
    // "experimentalDecorators": true,              /* Enables experimental support for ES7 decorators. */
    // "emitDecoratorMetadata": true,               /* Enables experimental support for emitting type metadata for decorators. */

    /* Advanced Options */
    "skipLibCheck": true,                           /* Skip type checking of declaration files. */
    "forceConsistentCasingInFileNames": true        /* Disallow inconsistently-cased references to the same file. */
  },
  "include": [ "src/**/*"],
  "exclude": [ "node_modules" ]
}

我的项目目录结构是这样的：

src
 -> app
    -> bootstrap
    -> api
    -> models
    -> ..... more directories
    -> server.ts

dist
 ->app //generated files in .js
    -> boostrap
    -> api
    -> ..... more directories
    -> server.js    

我的server.ts文件具有以下绝对工作导入：

import express from 'express';

import bootstrap from 'app/bootstrap'

import logger from 'app/services/logger';

const port = process.env.PORT || 8200;

const app = express();

bootstrap(app).then(mongo=>{
  app.listen({ port }, () => logger.info(`Server is listening on ${port}`));
}).catch(error=>{
  logger.error(error);
  process.exit(1);
});

问题是当这些.ts文件被编译并.js生成文件时。我在里面运行应用程序dist/app/server.js，我得到找不到模块错误，这是由于我的绝对路径导入而导致节点js抛出的错误。请帮我解决这个问题。

这是生成的server.js文件：

"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
var express_1 = __importDefault(require("express"));
var bootstrap_1 = __importDefault(require("app/bootstrap"));
var logger_1 = __importDefault(require("app/services/logger"));
var port = process.env.PORT || 8200;
var app = express_1.default();
bootstrap_1.default(app).then(function (mongo) {
    app.listen({ port: port }, function () { return logger_1.default.info("Server is listening on " + port); });
}).catch(function (error) {
    logger_1.default.error(error);
    process.exit(1);
});
//# sourceMappingURL=server.js.map

这里 require("app/bootstrap")和require("app/services/logger")正在产生错误。

Answer 1

TypeScript 编译器接受您的绝对导入，因为在tsconfig.json您指定的baseUrlto中"./src"，这意味着路径被解释为相对于src目录。

然而，NodeJS 会产生错误，因为它不以相同的方式解析导入。绝对导入预计来自某个node_modules文件夹。它接受require("./bootstrap")，不接受require("app/bootstrap")。

我建议你要么禁用baseUrl并迁移到相对导入，NodeJS 很好地支持了这一点；或者，您可以使用包捆绑器来转换导入。

Answer 2

也许你可以尝试路径

{
  "compilerOptions": {
    "baseUrl": "src",
    "paths": {
        "app/*": ["app/*"]
    },
}

但我个人更喜欢相对网址