最近把nestjs写的程序调整了一下，项目结构从Standard Mode该为Monorepo Mode，且把一些共用的模块提取出来，做成库。使用Nest CLI脚手架，执行了nest g lib db生成一个库，但是报错了：
Error: Invalid JSON character: "\"" at 13:6.
at _token (/root/recovery-backend/node_modules/-devkit/core/src/json/parser.js:81:19)
at _readProperty (/root/recovery-backend/node_modules/-devkit/core/src/json/parser.js:490:5)
at _readObject (/root/recovery-backend/node_modules/-devkit/core/src/json/parser.js:524:30)
at _readValue (/root/recovery-backend/node_modules/-devkit/core/src/json/parser.js:674:22)
at _readProperty (/root/recovery-backend/node_modules/-devkit/core/src/json/parser.js:491:19)
at _readObject (/root/recovery-backend/node_modules/-devkit/core/src/json/parser.js:515:26)
at _readValue (/root/recovery-backend/node_modules/-devkit/core/src/json/parser.js:674:22)
at parseJsonAst (/root/recovery-backend/node_modules/-devkit/core/src/json/parser.js:721:17)
at Object.parseJson (/root/recovery-backend/node_modules/-devkit/core/src/json/parser.js:750:24)
at updateJsonFile (/root/recovery-backend/node_modules//schematics/dist/lib/library/library.factory.js:110:29)
Failed to execute command: "/root/recovery-backend/node_modules/.bin/schematics" /schematics:library --name=db --no-dry-run --collection="@nestjs/schematics" --language="ts" --sourceRoot="apps/server/src" --spec虽然从错误信息得知是脚手架在解析JSON的时候出错了，但是却不知道具体的原因。我们先从报错的栈中/root/recovery-backend/node_modules/@nestjs/schematics/dist/lib/library/library.factory.js文件updateJsonFile函数中打印一下，看看sourceText是什么。
function updateJsonFile(host, path, callback) {
const source = host.read(path);
if (source) {
const sourceText = source.toString('utf-8');
console.log(sourceText) // 打印信息
const json = core_1.parseJson(sourceText);
callback(json);
host.overwrite(path, JSON.stringify(json, null, 2));
}
return host;
}{
"collection": "@nestjs/schematics",
"sourceRoot": "apps/server/src",
"monorepo": true,
"root": "apps/server",
"compilerOptions": {
"webpack": false,
"tsConfigPath": "apps/server/tsconfig.app.json"
},
"projects": {
"server": {
"type": "application",
"root": "apps/server",
"entryFile": "main",
"sourceRoot": "apps/server/src",
"compilerOptions": {
"webpack": false,
"tsConfigPath": "apps/server/tsconfig.app.json"
}
},
"admin": {
"type": "application",
"root": "apps/admin",
"entryFile": "main",
"sourceRoot": "apps/admin/src",
"compilerOptions": {
"webpack": false,
"tsConfigPath": "apps/admin/tsconfig.app.json"
}
}
}
}
{
"name": "recovery-backend",
"version": "0.0.1",
"description": "",
"author": "",
"license": "MIT",
"scripts": {
"prebuild": "rimraf dist",
"build": "nest build",
"format": "prettier --write \"apps/**/*.ts\" \"libs/**/*.ts\"",
"start": "nest start",
"start:dev": "nest start --watch",
"start:debug": "nest start --debug --watch",
"start:prod": "node dist/main",
"lint": "eslint '{src,apps,libs,test}/**/*.ts' --fix",
"test": "jest",
"test:watch": "jest --watch",
"test:cov": "jest --coverage",
"test:debug": "node --inspect-brk -r tsconfig-paths/register -r ts-node/register node_modules/.bin/jest --runInBand",
"test:e2e": "jest --config ./apps/recovery-backend/test/jest-e2e.json"
},
"dependencies": {
"@alicloud/pop-core": "^1.7.9",
"@nestjs/common": "^7.0.5",
"@nestjs/config": "^0.4.0",
"@nestjs/core": "^7.0.5",
"@nestjs/jwt": "^7.0.0",
"@nestjs/passport": "^7.0.0",
"@nestjs/platform-express": "^7.0.5",
"class-transformer": "^0.2.3",
"class-validator": "^0.11.1",
"co-wechat-oauth": "^2.0.1",
"crypto-js": "^4.0.0",
"mikro-orm": "^3.5.2",
"moment": "^2.24.0",
"mysql2": "^2.1.0",
"nestjs-mikro-orm": "^1.0.3",
"passport": "^0.4.1",
"passport-jwt": "^4.0.0",
"qcloudsms_js": "^0.1.1",
"querystring": "^0.2.0",
"reflect-metadata": "^0.1.13",
"rimraf": "^3.0.0",
"rxjs": "^6.5.4",
"wechat-jssdk": "^5.0.4"
},
"devDependencies": {
"@nestjs/cli": "^6.13.2",
"@nestjs/schematics": "^6.8.1",
"@nestjs/testing": "^6.11.11",
"@types/express": "^4.17.3",
"@types/jest": "25.1.1",
"@types/node": "^13.9.4",
"@types/passport-jwt": "^3.0.3",
"@types/supertest": "^2.0.8",
"@typescript-eslint/eslint-plugin": "^2.25.0",
"@typescript-eslint/parser": "^2.25.0",
"eslint": "^6.7.2",
"eslint-config-prettier": "^6.10.1",
"eslint-plugin-import": "^2.19.1",
"jest": "^24.9.0",
"prettier": "^1.18.2",
"supertest": "^4.0.2",
"ts-jest": "25.1.0",
"ts-loader": "^6.2.2",
"ts-node": "^8.8.1",
"tsconfig-paths": "^3.9.0",
"typescript": "^3.7.4"
},
"jest": {
"moduleFileExtensions": [
"js",
"json",
"ts"
],
"rootDir": ".",
"testRegex": ".spec.ts$",
"transform": {
"^.+\\.(t|j)s$": "ts-jest"
},
"coverageDirectory": "./coverage",
"testEnvironment": "node",
"roots": [
"<rootDir>/apps/"
]
},
"mikro-orm": {
"useTsNode": true,
"configPaths": [
"./apps/server/src/mikro-orm.config.ts",
"./dist/apps/server/mikro-orm.config.js"
]
}
}
{
"compilerOptions": {
"module": "commonjs",
"declaration": true,
"removeComments": true,
"emitDecoratorMetadata": true,
"experimentalDecorators": true,
"target": "es2017",
"sourceMap": true,
"outDir": "./dist",
"baseUrl": "./",
"incremental": true,
"esModuleInterop": true,
// "paths": {}
},
"exclude": [
"node_modules",
"dist"
]
}我们可以看到，打印出来的信息最下面的部分：
{
"compilerOptions": {
"module": "commonjs",
"declaration": true,
"removeComments": true,
"emitDecoratorMetadata": true,
"experimentalDecorators": true,
"target": "es2017",
"sourceMap": true,
"outDir": "./dist",
"baseUrl": "./",
"incremental": true,
"esModuleInterop": true,
// "paths": {}
},
"exclude": [
"node_modules",
"dist"
]
}其中的这一行被注释了
"paths": {}变成
// "paths": {}被注释掉了，我们知道，标准严格的JSON格式是不能有注释的。把该行改正问题即可解决。