Failed build script should not return exit code 0

[hexagon6]

When running the webpack build running npm run build in CI it should be possible to check for failure on the returned exit code.

Expected behaviour:

npm run build
# -> some build error happens
Error: Encountered errors while building app
    at /.../node_modules/sapper/cli.js:80:24
echo $?
127

What currently happens:

npm run build
# -> some build error happens
Error: Encountered errors while building app
    at /.../node_modules/sapper/cli.js:80:24
echo $?
0

This would allow detection of broken builds.

[hexagon6]

To resolve this we might want to add the --bail option to webpack: webpack/webpack#708 (comment)

[hexagon6]

Alternatively add the webpack-fail-plugin: https://github.com/teamdotjs/v2/pull/190/files

[Rich-Harris]

I agree — this is an issue with Sapper itself though rather than this project template, so I'll close this in favour of sveltejs/sapper#208. Thanks