No Provider for CustomPipe - angular 4

If you want to use pipe's transform() method in component, you also need to add CustomPipe to module's providers:

import  { CustomPipe } from '../pipes/custom.pipe';

...

@NgModule({
  imports:      [ .. ],
  declarations: [ CustomPipe ],
  exports:    [ CustomPipe ],
  providers:    [ CustomPipe ]
})
export class SharedModule { }

Apart from adding the CustomPipe to the module's provider list, an alternative is to add to the component's providers. This can be helpful if your custom pipe is used in only a few components.

import  { CustomPipe } from '../pipes/custom.pipe';
...
@Component({
    templateUrl: './some.component.html',
    ...
    providers: [CustomPipe]
})
export class SomeComponent{
    ...
}

Hope this helps.

You could also make the pipe Injectable (the same way it is done with the services you create using the cli):

    import { Injectable, Pipe, PipeTransform } from '@angular/core';

    @Pipe({
      name: 'customDecimalPipe'
    })
    @Injectable({
      providedIn: 'root'
    })
    export class CustomPipe extends PipeTransform {
      ...
    }