Fix: add build script to postinstall script

[yuleicul]

Pull Request

Purpose

This PR adds a npm run build script to postinstall script in /1-Authentication/1-Sign-in/App/package.json, to solve the following problem when running npm start

❯ npm start

> [email protected] start
> node server.js

node:internal/modules/cjs/loader:446
      throw err;
      ^

Error: Cannot find module 'C:\Users\Yulei_Chen\github\ms-identity-javascript-nodejs-tutorial\1-Authentication\1-sign-in\App\node_modules\msal-node-wrapper\dist\index.js'. Please verify that the package.json has a valid "main" entry
    at tryPackage (node:internal/modules/cjs/loader:438:19)
    at Module._findPath (node:internal/modules/cjs/loader:680:18)
    at Module._resolveFilename (node:internal/modules/cjs/loader:1063:27)
    at Module._load (node:internal/modules/cjs/loader:922:27)
    at Module.require (node:internal/modules/cjs/loader:1143:19)
    at require (node:internal/modules/cjs/helpers:121:18)
    at Object.<anonymous> (C:\Users\Yulei_Chen\github\ms-identity-javascript-nodejs-tutorial\1-Authentication\1-sign-in\App\app.js:9:32)
    at Module._compile (node:internal/modules/cjs/loader:1256:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1310:10)
    at Module.load (node:internal/modules/cjs/loader:1119:32) {
  code: 'MODULE_NOT_FOUND',
  path: 'C:\\Users\\Yulei_Chen\\github\\ms-identity-javascript-nodejs-tutorial\\1-Authentication\\1-sign-in\\App\\node_modules\\msal-node-wrapper\\package.json',   
  requestPath: 'msal-node-wrapper'
}

Node.js v18.17.1

This bug is because it's the first time I run npm start in any chapter, the helper inside /Common hasn't been built before.
Actually, we need to add npm run build to every postinstall in case of the above bug, but this PR just adds for /1-Authentication/1-sign-in/.

Does this introduce a breaking change

    [ ] Yes
    [x] No

Pull request type

What kind of change does this Pull Request introduce?

    [x] Bugfix
    [ ] Feature
    [ ] Code style update (formatting, local variables)
    [ ] Documentation content changes
    [ ] Other... Please describe:

How to test

• Get the code

    git clone https://github.com/yuleicul/ms-identity-javascript-nodejs-tutorial.git
    cd ms-identity-javascript-nodejs-tutorial
    git checkout yulei-patch-1
    cd 1-Authentication/1-sign-in/App
    npm install
    npm start

What to check

ex: verify that the following are valid:

• The server can be started successfully after running npm start

Other Information

Related issue: Please Fix the following issue I was having when running npm start in sample \4-AccessControl\2-security-groups · Issue #100 · Azure-Samples/ms-identity-javascript-nodejs-tutorial

[SimonHylander]

This solved the problem for me