webpack silently continues despite typescript errors - coffeescript

Question

I'm playing around with typescript in an existing coffeescript project that uses gulp and webpack.
I noticed when there's a syntax error in the coffeescript, it will fail the gulp task and not continue with the following steps, which is the desired behavior. With the typescript loader I'm using (ts-loader), I can see error messages in the terminal, but the webpack task succeeds from gulp's perspective and continues on. I imagine this is a difference in how the coffeescript loader and the typescript loader handle errors.
For example, I can add the following typescript file:
function greet(name: string) {
return 'Hello '+name;
}
export = greet;
{
and see the error in the build:
ERROR in ./bin/arranged/webkit/hcube/dummy.ts
(8,1): error TS1005: '}' expected.
but it still continues with the rest of the build like webpack didn't return any errors.
I realize that unlike coffeescript, typescript has a lot of inter-file dependencies, which makes the ts-loader much more complex, but I feel like it should still be failing at some point. Running the typescript compiler on the command line returns the expected exit code when there are syntax errors, so I feel like the problem lies in the loader itself.
In the after-compile plugin of ts-loader should it be reporting errors to webpack differently to propogate up? Right now it looks like it just attaches the errors to webpack in the after-compile plugin and webpack just keeps on trucking (see https://github.com/TypeStrong/ts-loader/blob/master/index.ts#L398). Should the loader be raising an error in this plugin if errors are encountered? Or calling the callback differently? Or should this be handled in some other part of the loader? Again, this particular example is a syntax error, so I imagine it would be caught/raised before after-compile is executed.