Error messages are not detailed enough

[shancarter]

When building with webpack (either in dev mode or as a build step), these are the sorts of error messages I see, missing line or column information or more detailed context:

ERROR in ./components/Contour.html
Module build failed: Error: ParseError: Unexpected token
    at Object.module.exports (../node_modules/svelte-loader/index.js:36:19)
 @ ./components/contour.js 3:15-40

I made an attempt at a [PR}(https://github.com//pull/26) to get more context, and it works locally but I seem to have screwed something up.

[shancarter]

For instance, if you introduce a syntax error into the webpack2 example provided, this is the complete error message that is output by webpack:

(node:32434) DeprecationWarning: loaderUtils.parseQuery() received a non-string value which can be problematic, see https://github.com/webpack/loader-utils/issues/56
parseQuery() will be replaced with getOptions() in the next major version of loader-utils.
Unexpected token
Hash: 1b01db851aa2f4e289c8
Version: webpack 2.6.1
Time: 631ms
   Asset     Size  Chunks             Chunk Names
index.js  15.8 kB       0  [emitted]  index
   [0] ./src/index.js 248 bytes {0} [built]
   [1] ./src/counter.html 6.71 kB {0} [built]
   [2] ./src/header.html 229 bytes {0} [built] [failed] [2 errors]
   [3] multi ./src/index.js 28 bytes {0} [built]

ERROR in ./src/header.html
(Emitted value instead of an instance of Error) Unexpected token
 @ ./src/counter.html 3:0-30
 @ ./src/index.js
 @ multi ./src/index.js

ERROR in ./src/header.html
Module build failed: TypeError: Cannot match against 'undefined' or 'null'.
    at Object.module.exports (/Users/shancarter/development/svelte-loader/example/webpack2/node_modules/svelte-loader/index.js:9:25)
 @ ./src/counter.html 3:0-30
 @ ./src/index.js
 @ multi ./src/index.js

[nikku]

PR #26 merged so I guess this can be closed?