store: Improve conflicting root error message

[charlieegan3]

Fixes #7806

$ opa eval -b b1.tar.gz -b b2.tar.gz data;  go run main.go eval -b b1.tar.gz -b b2.tar.gz data
{
  "errors": [
    {
      "message": "detected overlapping roots in bundle manifest with: [b1.tar.gz b2.tar.gz]"
    }
  ]
}
{
  "errors": [
    {
      "message": "bundles b2.tar.gz, b1.tar.gz have overlapping roots and cannot be activated simultaneously because bundles b1.tar.gz specify empty root paths ('') which overlap with any other bundle root"
    }
  ]
}

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[srenatus]

"...bundles %s specify..." 🤔 OK this is 100% pedantry, but let's do a compromise:

Suggested change

	return fmt.Errorf("bundles %s have overlapping roots and cannot be activated simultaneously because bundles %s specify empty root paths ('') which overlap with any other bundle root", strings.Join(bundleNames, ", "), strings.Join(bundlesWithEmptyRoots, ", "))
	return fmt.Errorf("bundles %s have overlapping roots and cannot be activated simultaneously because bundle(s) %s specify empty root paths ('') which overlap with any other bundle root", strings.Join(bundleNames, ", "), strings.Join(bundlesWithEmptyRoots, ", "))

[charlieegan3]

I had the same thought, I am making some minor updates to the messages!

[charlieegan3]

Ok, Changed it to:

{
  "errors": [
    {
      "message": "detected overlapping roots in bundle manifest with: [b2.tar.gz b1.tar.gz]"
    }
  ]
}
{
  "errors": [
    {
      "message": "bundles [b1.tar.gz, b2.tar.gz] have overlapping roots and cannot be activated simultaneously because bundle(s) [b1.tar.gz] specify empty root paths ('') which overlap with any other bundle root"
    }
  ]
}

Along with some other edits.

[charlieegan3]

Let me see if I can get this to show the longer message too.

[srenatus]

Thanks!

[charlieegan3]

Thanks Stephan! added some fixes to the tests in https://github.com/open-policy-agent/opa/pull/7808/files#diff-2923c292692c11e167d80502ff31fb2c991c92cec3ae3686e1acf756fc02e7d4, but will merge when all passing