[APM] Convert camelCase to snake_case for all files and folders

[sorenlouv]

Kibana is using snake_case for all files and folders but APM has a mixed filenaming scheme. APM should use snake_case like the rest of Kibana.
APM has disabled Kibana's filename check. This check should be re-enabled again.

Steps

1. Remove/uncomment the following lines to re-add case-checking of APM files:
   

   kibana/src/dev/precommit_hook/casing_check_config.js

   Lines 60 to 64 in 9d42d67

   	// TODO fix file names in APM to remove these
   	'x-pack/plugins/apm/public/**/*',
   	'x-pack/plugins/apm/scripts/**/*',
   	'x-pack/plugins/apm/e2e/**/*',

2. Run node scripts/check_file_casing.js from kibana root

3. Fix all the filename errors listed in the step above

4. Run node scripts/check_file_casing.js again to verify all errors are fixed

Notes
If you're on a platform with a case-insensitive filesystem (macOS by default), you'll need to have

[core]
	ignorecase = false

in .git/config.

If you're just changing the casing of a filename (from upper to lowercase) you may need to use git mv -f to rename the files and make sure github notices.

Tasks

• x-pack/plugins/apm/public/**/*
• x-pack/plugins/apm/scripts/**/*

[elasticmachine]

Pinging @elastic/apm-ui (Team:apm)

[mohitsaxenaknoldus]

Please assign it to me, I'll do it. Also, tell me which files and folders you want me to include.

[smith]

@mohitsaxenaknoldus if you delete these lines: https://github.com/smith/kibana/blob/7216bab3521bd395a019ef8af3392d25f0f912a6/src/dev/precommit_hook/casing_check_config.js#L60-L64

Then run node scripts/check_file_casing.js from the kibana root, all the filenames it outputs in x-pack/plugins/apm are the ones that need changed.

If you're on a platform with a case-insensitive filesystem (macOS by default), you'll need to have

[core]
	ignorecase = false

in .git/config.

If you're just changing the casing of a filename (from upper to lowercase) you may need to use git mv -f to rename the files and make sure github notices.

I've tried doing this with some automated tools, but there might be a lot of work that has to be done manually.

If you're doing this work you'll want to be fetching from upstream (elastic/kibana) and merging from upstream frequently as code is changing quite often in Kibana and this kind of change can have a lot of conflicts if not kept up to date.

Please let me know if you have any problems or questions.

[sorenlouv]

Thanks @smith! I've added your comment to the issue description.

[mohitsaxenaknoldus]

When I do: node scripts/check_file_casing.js Its giving me this:

Error: Cannot find module '@kbn/optimizer'
Require stack:
- /home/knoldus/OS/kibana/src/setup_node_env/index.js
- /home/knoldus/OS/kibana/scripts/check_file_casing.js
    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:902:15)
    at Module.Hook._require.Module.require (/home/knoldus/OS/kibana/node_modules/require-in-the-middle/index.js:61:29)
    at require (internal/modules/cjs/helpers.js:92:18)
    at Object.<anonymous> (/home/knoldus/OS/kibana/src/setup_node_env/index.js:11:1)
    at Module._compile (internal/modules/cjs/loader.js:1085:14)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1114:10)
    at Module.load (internal/modules/cjs/loader.js:950:32)
    at Function.Module._load (internal/modules/cjs/loader.js:790:14)
    at Module.require (internal/modules/cjs/loader.js:974:19)
    at require (internal/modules/cjs/helpers.js:92:18)

[smith]

@mohitsaxenaknoldus you probably need to run yarn kbn bootstrap to make sure all dependencies are installed and set up. See https://www.elastic.co/guide/en/kibana/master/development-getting-started.html for more.

[kpatticha]

I'm working on renaming all the files in x-pack/plugins/apm/public/**/* folder.
Draft PR to track the progress #119899