feature: migrate users old config to new config with a Renovatebot PR

[HonkingGoose]

Introduction

I saw that a user had a problem with masterIssue not passing the Renovate validation properly.
Well of course it does not pass the validation, because it was the wrong term, they should have used masterIssueApproval... 😄

But then I wondered, how do we handle masterIssueApproval?

So I set up a reproduction repo to test what the bot does now.
You can find my repo here: https://github.com/HonkingGoose/validate-masterIssueApproval-migration

What would you like Renovate to be able to do?

To the best of my knowledge, the bot silently migrates the "bad config" to a "good config" behind the scenes.

I was thinking it would be nice if the Renovate bot opens a PR to migrate old terms to new terms.
Something like: "migrate masterIssueApproval to dependencyDashboardApproval".
This way the user is always using current and supported terms in their config.

Relevant snippet of log

The bot already knows that some config migration is necessary.
It also seems to silently migrate/massage the config into the right shape.

{
  "renovateVersion": "24.12.4"
}

DEBUG: Found .github/renovate.json5 config file
DEBUG: Repository config
{
  "fileName": ".github/renovate.json5",
  "config": {
    "extends": [
      "config:base"
    ],
    "masterIssueApproval": true
  }
}
DEBUG: migrateAndValidate()
DEBUG: Config migration necessary
{
  "oldConfig": {
    "extends": [
      "github>whitesource/merge-confidence:beta",
      "config:base"
    ],
    "masterIssueApproval": true
  },
  "newConfig": {
    "extends": [
      "github>whitesource/merge-confidence:beta",
      "config:base"
    ],
    "dependencyDashboardApproval": true
  }
}
DEBUG: massaged config
{
  "config": {
    "extends": [
      "github>whitesource/merge-confidence:beta",
      "config:base"
    ],
    "dependencyDashboardApproval": true
  }
}
DEBUG: migrated config
{
  "config": {
    "extends": [
      "github>whitesource/merge-confidence:beta",
      "config:base"
    ],
    "dependencyDashboardApproval": true
  }
}

Did you already have any implementation ideas?

Maybe we can use the migrated config from the DEBUG log in some way?

[rarkins]

I thought we had an existing issue for this but can't find it. It should be the migrated config we use.

[HonkingGoose]

Turns out none of these issues are related... 😄

---

@rarkins are you thinking of this one? #7572

Issue #1647 seems like it might be related as well.

[rarkins]

No, neither of them are the same

[HonkingGoose]

I thought we had an existing issue for this but can't find it.

@rarkins I think I found the earlier issue: #1502

Do you want me to mark my newer issue (#8235) as a duplicate of the earlier one?

[rarkins]

Duplicate of #1502