When you are creating your project with angular cli try this:

ng new My_New_Project --style=sass

This generating all your components with predifined sass files.

If you want scss syntax create your project with :

ng new My_New_Project --style=scss

Cli handles the rest of it.

Angular-cli also adds an option to change the default css preprocessor after the project has been created by using the command:

ng set defaults.styleExt scss

which was fixed by changing the lines ofangular-cli.json,

"styles": [

"styles.css"

],

to

"styles": [

"styles.sass"

],