title: Ng build error: Property 'avatar' does not exist on type 'User
body: <p>I am new to web development. We are using angular and ts. When my other developer build the code it works properly on his system.
  But when I do ng build I get this error: [This is just the partial error]</p>
  <pre><code>#14 49.12 Compiling @angular/material/datepicker : es2015 as esm2015
  #14 123.4 ✔ Browser application bundle generation complete.
  #14 123.4 ✔ Browser application bundle generation complete.
  #14 123.4
  #14 123.4 ./node_modules/@angular/material/__ivy_ngcc__/fesm2015/core.js:150:26-44 - Error: export '_isTestEnvironment' (imported as '_isTestEnvironment') was not found in '@angular/cdk/platform' (possible exports: Platform, PlatformModule, _getEventTarget, _getFocusedElementPierceShadowDom, _getShadowRoot, _supportsShadowDom, getRtlScrollAxisType, getSupportedInputTypes, normalizePassiveListenerOptions, supportsPassiveEventListeners, supportsScrollBehavior)
  #14 123.4
  #14 123.4 Error: src/app/layout/common/user/user.component.html:5:40 - error TS2339: Property 'avatar' does not exist on type 'User'.
  #14 123.4
  #14 123.4 5             *ngIf=&quot;showAvatar &amp;&amp; user?.avatar&quot;
  #14 123.4                                          ~~~~~~
  #14 123.4
  #14 123.4   src/app/layout/common/user/user.component.ts:19:18
  #14 123.4     19     templateUrl: './user.component.html',
  #14 123.4                         ~~~~~~~~~~~~~~~~~~~~~~~
  #14 123.4     Error occurs in the template of component UserComponent.
  </code></pre>
  <p>from Css Minimizer</p>
  <p>my docker file:</p>
  <pre><code># BASE IMAGE with an alias #
  FROM node:12
  RUN mkdir /app
  WORKDIR /app
  COPY package.json /app
  COPY . /app
  RUN npm install -g @angular/cli
  RUN     npm install tsc -g
  RUN npm install
  
  COPY . .
  
  RUN ng build
  </code></pre>
  <p>Please guide me?
  Thank you in advance</p>