Testing Components In Angular: NO ERRORS SCHEMA, Stub Components, and NgMocks

Testing Angular components becomes complex when they have child component dependencies, external libraries, or directives. Three approaches are compared: NO_ERRORS_SCHEMA (quick but hides template errors and reduces coverage), stub components (more control but requires manual maintenance), and NgMocks (recommended, using MockBuilder and MockRender to isolate components with minimal boilerplate). A practical scenario with ProductsComponent depending on ProductsListComponent and a Kendo UI listview illustrates the tradeoffs of each approach.