Use Microsoft's JSONC parser to allow nvim-dap to read launch.json with comments, trailing comma, ...

[brianhuster]

1. Install Nvim's node-client globally

nvim install -g neovim

2. Create file ~/.config/nvim/rplugin/node/jsonc/index.js and set current directory to its parent

:e `=stdpath('config') .. /rplugin/node/jsonc/index.js`
:w ++p
:cd %:h

3. Install local dependencies

npm i jsonc-parser neovim

4. Add the following to the file index.js you just created. This Javascript snippet defines a Vimscript function JsoncDecode() that you can call from Lua as well

const { parse } = require('jsonc-parser')

/**
  * @param { import('neovim').NvimPlugin } plugin
  */
module.exports = (plugin) => {
	plugin.setOptions({ dev: false });
	plugin.registerFunction(
		'JsoncDecode', async (args) => {
			const [ json ] = args
			if (typeof(json) !== 'string') {
				plugin.nvim.call('nvim_echo', [
					[[ 'Error calling vimscript function JsoncDecode: expect a string' ]],
					true,
					{ err: true }
				])
				return;
			}
			return parse(json);
		},
		{ sync: true }
	);
};

5. Add the following to your nvim-dap config

require('dap.ext.vscode').json_decode = vim.fn.JsoncDecode

6. Run :UpdateRemotePlugin and restart Nvim