babel-node: this.log is not a function

[JamieMagee]

I'm trying to add njsTrace to Renovate. It works fine when running with nodejs, but when using babel-node, which we use for debugging, I get the following stacktrace:

TypeError: this.log is not a function
    at NJSTrace.inject (/home/jamie/code/renovate/node_modules/njstrace/njsTrace.js:73:7)
    at levels (/home/jamie/code/renovate/lib/logger/index.ts:129:5)
    at Object.parseConfigs (/home/jamie/code/renovate/lib/config/index.ts:70:3)
    at process._tickCallback (internal/process/next_tick.js:68:7)
    at Function.Module.runMain (internal/modules/cjs/loader.js:834:11)
    at Object.<anonymous> (/home/jamie/code/renovate/node_modules/@babel/node/lib/_babel-node.js:180:21)
    at Module._compile (internal/modules/cjs/loader.js:775:14)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:789:10)
    at Module.load (internal/modules/cjs/loader.js:653:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
    at Function.Module._load (internal/modules/cjs/loader.js:585:3)
    at Function.Module.runMain (internal/modules/cjs/loader.js:831:12)
    at startup (internal/bootstrap/node.js:283:19)
    at bootstrapNodeJSCore (internal/bootstrap/node.js:623:3

Here's my PR so far renovatebot/renovate#5632.

Any suggestions or help would be greatly appreciated.

[ValYouW]

Does babel-node compiles the code? you will have to see what's the actual output that is being run in order to see why... log is a prototype function of NJSTrace and there is no reason for it not to be on this...

[JamieMagee]

Yes. It's effectively a wrapper around Node.js, with the benefit of compiling babel presets and plugins.

Any idea how I can inspect the output?

[ValYouW]

Never worked with it, maybe if you can run it in debugger you'll see the code(?)
You can edit node_modules/njstrace/njsTrace.js and insert a debugger; command to trigger a breakpoint where you want (I would say line 72 which is before the crash)...