How to install @types/node by docker RUN inside Dockerfile

Question

When I use the following Dockerfile:

FROM node:22-alpine

ENV NODE_ENV production

WORKDIR /usr/web-server

RUN npm i -g @nestjs/cli typescript

COPY ./package*.json ./

RUN npm install
RUN npm install @types/node

COPY ./ ./

EXPOSE 4000

CMD npm run start:dev

inside /usr/web-server/node_modules/@types node folder not installed.

However, if I use the Dockerfile below:

FROM node:22-alpine

ENV NODE_ENV production

WORKDIR /usr/web-server

RUN npm i -g @nestjs/cli typescript

COPY ./package*.json ./
RUN npm install
RUN npm uninstall @types/node
RUN npm install @types/node

COPY ./ ./

EXPOSE 4000

CMD npm run start:dev

everything works fine.

Why in first Dockerfile RUN npm install @types/node doesn't install node folder inside @types?

I try to RUN npm install @types/node after COPY ./ ./ but it doesn't work either

Answer 1

I this case it doesn't work in the first Dockerfile because @type/node was installed like dev dependency in package.json

"devDependencies": {
   "@types/node": "^20.12.12",
}

When i install it like RUN npm install @types/node inside Dockerfile, it doesn't add node folder inside @types in node_modules, because @types/node not istalled if it like devDependeces package.

When jumping into the Docker container:

cd /usr/web-server/node_modules/@types
ls 
// result empty folder

However, when i uninstall it and install it again as main dependency, it work fine:

cd /usr/web-server/node_modules/@types
ls 
// Now result is node folder

thats why the second Docker file is worked fine

and if i add packege @type/node like main dependence in package.json file:

"dependencies": {
   "@types/node": "^20.12.12",
}

Now I dont need to add RUN npm install/unistall @types/node in Dockerfile.

The remaining question is why @types/node is not installed in the container as a devDependency, but that's another issue already.