Created by: jasonLaster
Fixes issue
Switches webpack's devtool mode from cheap-module-source-map to source-map so that the mappings include column positions.
This enables variable and scope mappings in Firefox, which makes it easier to debug applications built with webpack and babel. This should fix the this mapping issue. It will also simplify the scopes pane by showing the "original" scopes and variables. It will also enable in-line code preview and console support when evaluating "original" expressions.
The incremental build times were 25% slower for source-map vs cheap-module-source-maps (500ms vs 400ms) on a simple app. I believe that webpack's cache means that these numbers would not be that different on a larger app.
Both modes had equivalent breakpoint support on page load and while the app was running.
Chrome
Firefox
