User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:64.0) Gecko/20100101 Firefox/64.0 Steps to reproduce: I found that when I using debugger to step into the switch statement, the Devtools navigates to the transformed js file. Here is a test typescript project: https://github.com/harytfw/devtool-bug Actual results: Devtools navigates to the transformed js file. Expected results: Devtools should stay in the source file.

Looks like the issue is that the column offset we get from Spidermonkey for the `case` state is `0`, which does not have a mapping to an original file. I fixed a bunch of these in https://bugzilla.mozilla.org/show_bug.cgi?id=1472291 bug it looks like we missed this one.

Example: > var global = newGlobal(); > var dbg = new Debugger(global); > dbg.onDebuggerStatement = onDebuggerStatement; > > global.eval(` > debugger; > var name = {}; > switch (name) { > case name: > console.log('I like apple'); > break; > default: > break; > } > `); > > function onDebuggerStatement(frame) { > const { script } = frame; > > console.log(JSON.stringify(script.getAllColumnOffsets(), null, 2)); > } will log > // ... > { > "lineNumber": 5, > "columnNumber": 0, > "offset": 29 > }, > // ... Note how the columnNumber for that `case` should be `4`.