Is there a way to read/write the renovate config programmatically?

[mmkal]

What would you like help with?

I would like help with my configuration

How are you running Renovate?

Mend Renovate hosted app on github.com

If you're self-hosting Renovate, tell us which platform (GitHub, GitLab, etc) and which version of Renovate.

GitHub

Please tell us more about your question or problem

I am working on a GitHub action which helps set up a renovate config that follows a certain recipe.

It's a GitHub Action, and I'd like to make it as hands-off as possible, so I'm hoping to actually open a pull request proposing a change to (or addition of) the user's renovate config directly. But, there are many different renovate config formats, so I'm wondering if there's a helper exposed as part of the renovate npm package. Something like this would be great:

import {readConfig, writeConfig} from 'renovate'

const config = readConfig() // gets from renovate.json, or renovate.json5, or .github/renovate.json, etc....

Object.assign(config, {
  "$schema": "https://docs.renovatebot.com/renovate-schema.json",
  "baseBranches": ["deps"],
  "automerge": true,
  "automergeType": "branch",
  "extends": [
    "config:recommended"
  ],
  "fetchChangeLogs": "branch",
  "commitBody": "{{#if logJSON.hasReleaseNotes}}{{#each logJSON.versions as |release|}}{{# if release.releaseNotes}}##### [v{{{release.version}}}]({{{release.releaseNotes.url}}})\n\n{{{release.releaseNotes.body}}}{{/if}}{{/each}}{{/if}}"
})

writeConfig(config) // checks if an existing file exists, and writes to the its location if so, or renovate.json if not

It wouldn't be too hard to use the json5 module to do this manually, but it seems like the sort of problem that must have already been solved internally - if it could just be exposed via the package it'd be useful.

Logs (if relevant)

N/A