Allow JSON5 features such as trailing commas in editor configs

[SgtPooki]

This issue is related to #407

🐛 Bug Report

• tslint-to-eslint-config version: 1.5.0
• ESLint version: ^7.10.0
• Node version: 12.18.3

Actual Behavior

tslint-to-eslint-config overwrite's entire .vscode/settings.json with an empty config if there is a trailing comma

With trailing comma

diff --git a/.vscode/settings.json b/.vscode/settings.json
index 44f8082..ca2996c 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -1,3 +1,14 @@
-{
-    "editor.formatOnSave": true,
-}
+/*
+👋 Hi! This file was autogenerated by tslint-to-eslint-config.
+https://github.com/typescript-eslint/tslint-to-eslint-config
+
+It represents the closest reasonable ESLint configuration to this
+project's original TSLint configuration.
+
+We recommend eventually switching this configuration to extend from
+the recommended rulesets in typescript-eslint. 
+https://github.com/typescript-eslint/tslint-to-eslint-config/blob/master/docs/FAQs.md
+
+Happy linting! 💖
+*/
+{}

Without trailing comma

diff --git a/.vscode/settings.json b/.vscode/settings.json
index f89ed5f..1eadf3f 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -1,3 +1,16 @@
+/*
+👋 Hi! This file was autogenerated by tslint-to-eslint-config.
+https://github.com/typescript-eslint/tslint-to-eslint-config
+
+It represents the closest reasonable ESLint configuration to this
+project's original TSLint configuration.
+
+We recommend eventually switching this configuration to extend from
+the recommended rulesets in typescript-eslint. 
+https://github.com/typescript-eslint/tslint-to-eslint-config/blob/master/docs/FAQs.md
+
+Happy linting! 💖
+*/
 {
     "editor.formatOnSave": true
 }

Expected Behavior

1. The actual bug represented in this issue

It should accept trailing commas as they are valid in vscode configs.

2. The bigger, not exactly this bug, but related problem:

It should not overwrite any settings in .vscode/* folder without an explicit option.

From the readme:

The tslint-to-eslint-config command reads in any existing linter, TypeScript, and package configuration files, then creates an .eslintrc.js result based on them.

This does not indicate it's going to modify my editor files at all, only that it will create a new file, .eslintrc.js. Please require an option/flag for any changes to editor configs!

Reproduction

Add a trailing comma to your last item in your .vscode/settings.json, and run tslint-to-eslint-config, you'll see that it outputs an empty object.

[SgtPooki]

You should replace all use of JSON.stringify with json5.stringify

[JoshuaKGoldberg]

Thanks for reporting @SgtPooki! Agreed on both counts. Forking out to a couple issues to track the added proposals:

• Use a diff writer instead of complete override for JSON editor config conversions #744: writing the new config with a diff-based approach
• Switch editor config conversions to opt-in #745: changing the editor conversion behavior to opt-in

Let's use this issue should track using a JSON5 parser to read in the original settings. tslint-to-eslint-config should allow VS Code configs that include JSON5 features such as trailing commas and comments.

[SgtPooki]

Beautiful... Y'all made quick work here. I put the project I was working on down to work on something else, and now that i'm back to it... you've merged the fix! =D