refactoring: call git via execSync only once

[Snaptags]

You can use a custom git log format to extract all required information at once. The available placeholders (https://git-scm.com/docs/git-log#_pretty_formats) are quite powerful, you can even use them to generate a JSON string to be parsed automatically.

For this I added two functions:

• gitLogToJSON: defines the custom format and runs git once to get the result. There are two problems to consider here: at least git commit messages may contain quotes (") as well as new line characters, both requiring special treatment in a JSON string. To handle both cases I use a very weird separator string to be able to first escape all quotes inside the values. After that the placeholder is replaced by quote to get a valid JSON. This of course will break if anyone actually uses the placeholder string in a commit message. Not very likely to happen :-)
• parseRefs: git's %D format placeholder returns refs as comma-separated string, e.g. "HEAD -> master, tag: v1.1.0, tag: bugfix". The function parses this into the branch name and an array of tag names.

This might not be the very best solution, but at least we don't have to call git 6 times.

[AbhyudayaSharma]

Thanks a lot for your contributions @Snaptags ! I always wanted to do this.

This looks fine but there are some things that may cause issues. I think we can probably do all this with three execSync calls.

1. Commit details using git log '--format=%h%n%H%n%cI%n%B'
2. Tags using git tag --list --points-at HEAD
3. Current branch using git rev-parse --abbrev-ref HEAD

What do you think about this?

I wish we could've gotten the current branch using git log but pretty-formats has nothing about getting branch names.

[AbhyudayaSharma]

I think it is better to wait for this to get merged too before cutting a new release consisting of just #4. If you need #4 urgently, let me know.

[AbhyudayaSharma]

Thanks again @Snaptags ! Looks perfect now, just some minor suggestions.

[AbhyudayaSharma]

Thanks @Snaptags !