Cannot find module '@fastify/session' or its corresponding type declarations

[RedBoardDev]

Prerequisites

• [X] I have written a descriptive issue title
• [X] I have searched existing issues to ensure the bug has not already been reported

Fastify version

5.0.0

Plugin version

3.0.1

Node.js version

20.17.0

Operating system

Linux

Operating system version (i.e. 20.04, 11.3, 10)

UX425QA.306

Description

I have a typescript compilation error in the typing module. When I run ‘tsc --noEmit’, I get this error:

node_modules/@fastify/passport/dist/session-managers/SecureSessionManager.d.ts:4:38 - error TS2307: Cannot find module '@fastify/session' or its corresponding type declarations.

4 import { FastifySessionObject } from '@fastify/session';
                                       ~~~~~~~~~~~~~~~~~~

Found 1 error in node_modules/@fastify/passport/dist/session-managers/SecureSessionManager.d.ts:4

And all my dependencies from package.json:

    "@fastify/cors": "^10.0.1",
    "@fastify/helmet": "^12.0.1",
    "@fastify/passport": "^3.0.1",
    "@fastify/rate-limit": "^10.1.1",
    "@fastify/secure-session": "^8.1.0",
    "@fastify/swagger": "^9.1.0",
    "@fastify/swagger-ui": "^5.0.1",
    "@prisma/client": "^5.20.0",
    "ajv": "^8.17.1",
    "ajv-formats": "^3.0.1",
    "bcrypt": "^5.1.1",
    "dotenv": "^16.4.5",
    "fastify": "^5.0.0",
    "handlebars": "^4.7.8",
    "json-schema-to-ts": "^3.1.1",
    "jsonwebtoken": "^9.0.2",
    "nodemailer": "^6.9.15",
    "passport-local": "^1.0.0"
  },
  "devDependencies": {
    "@types/bcrypt": "^5.0.2",
    "@types/cors": "^2.8.17",
    "@types/jsonwebtoken": "^9.0.7",
    "@types/node": "^22.5.5",
    "@types/nodemailer": "^6.4.16",
    "@types/passport": "^1.0.16",
    "@types/passport-local": "^1.0.38",
    "eslint-plugin-import": "^2.31.0",
    "eslint-plugin-unused-imports": "^4.1.4",
    "husky": "^9.1.6",
    "prettier": "^3.3.3",
    "prisma": "^5.20.0",
    "ts-node": "^10.9.2",
    "ts-node-dev": "^2.0.0",
    "tsconfig-paths": "^4.2.0",
    "typescript": "^5.6.0",
    "typescript-eslint": "^8.8.0"
  }

tsconfig.json:

{
  "extends": "./tsconfig.base.json",
  "ts-node": {
    "transpileOnly": true,
    "require": ["tsconfig-paths/register"]
  },
  "include": ["app/**/*.ts"],
  "exclude": ["dist", "node_modules"]
}

tsconfig.base.json:

{
  "compilerOptions": {
    "lib": ["ESNext"],
    "moduleResolution": "node",
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    "removeComments": true,
    "strict": true,
    "forceConsistentCasingInFileNames": true,
    "sourceMap": true,
    "target": "ES2020",
    "esModuleInterop": true,
    "outDir": "./dist",
    "allowSyntheticDefaultImports": true,
    "resolveJsonModule": true,
    "types": ["node"],
    "typeRoots": ["./node_modules/@types", "./app/src/entities"],
    "baseUrl": "./app/src",
    "paths": {
      "@fonts": ["assets/fonts/*"],
      "@icons": ["assets/icons/*"],
      "@images": ["assets/images/*"],
      "@config/*": ["config/*"],
      "@entities/*": ["entities/*"],
      "@enums/*": ["enums/*"],
      "@libs/*": ["libs/*"],
      "@middlewares/*": ["middlewares/*"],
      "@repositories/*": ["repositories/*"],
      "@routes/*": ["routes/*"],
      "@services/*": ["services/*"],
      "@templates": ["templates/*"],
      "@utils": ["libs/utils/index.ts"]
    },
    "strictNullChecks": true
  }
}

Don't hesitate if you see any inconsistencies in these files too !

Link to code that reproduces the bug

No response

Expected Behavior

No response

[mcollina]

I think this was introduced in https://github.com/fastify/fastify-passport/pull/1198. A workaround for you could be to use the skipLibCheck option.

cc @robwalkerco @simoneb - I have absolutely no idea how to type this.

[RedBoardDev]

Yeah, but I want to avoid skipLibCheck to have a nice CI ! But for now I'm using it yes

[robwalkerco]

The Session and Secure-session packages are used for some of the types, but they are dev dependencies https://github.com/fastify/fastify-passport/blob/223d097ce47b62210054714959c7007a0b518471/package.json#L48-L49 This lets the types work great when developing, but causes the error when checking the types when the dev dependencies are not installed, such as in a production CI environment.

I'll have to do some research tomorrow on the best way to handle this scenario, as I guess the preference would be to avoid making them dependencies.

[robwalkerco]

I've tried to find a nice way to make this work well, and have yet to find a great solution.

I have managed to make it work with some type changes in @fastify/session and @fastify/secure-session, but that breaks the existing SessionData typing :(

I will continue to investigate when I next get some time

[eiskalteschatten]

I'm also having this issue which is preventing me from updating...