ReplSession.addBreakpoint(location: string): Promise<Breakpoint | string>
Stops the page at file:line without a debugger statement in the source.
The line is yours, not the bundle's — it is mapped through the same source map that turns a stack frame back into a file you wrote. Lands on the nearest line at or after the one asked for, since a blank line or a comment has no code to stop on, and says which one it settled on.
Promise<Breakpoint | string>