Generate changes for new or deleted schemas

[jdolle]

Description

Ref CONSOLE-1540

Showing a list of changes can be useful even for new or deleted schemas.

This change allows null to be passed to diff as either the old and/or new schema.

Currently, on Hive, checking a new schema shows "no changes". This isn't harmful since additions are safe, but it's confusing. Showing a full list of additions in the new schema would make much more sense.

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

See unit tests

Checklist:

• I have followed the
  CONTRIBUTING doc and the
  style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[github-actions]

💻 Website Preview

The latest changes are available as preview in: https://pr-2923.graphql-inspector.pages.dev

[github-actions]

🚀 Snapshot Release (alpha)

The latest changes of this PR are available as alpha on npm (based on the declared changesets):

Package	Version	Info
@graphql-inspector/action	5.0.16-alpha-20251120235634-88fd4e9a4cbe3ef4792bdd0a808b897ac20ae425	npm ↗︎ unpkg ↗︎
@graphql-inspector/cli	6.0.4-alpha-20251120235634-88fd4e9a4cbe3ef4792bdd0a808b897ac20ae425	npm ↗︎ unpkg ↗︎
@graphql-inspector/audit-command	5.0.16-alpha-20251120235634-88fd4e9a4cbe3ef4792bdd0a808b897ac20ae425	npm ↗︎ unpkg ↗︎
@graphql-inspector/coverage-command	6.1.10-alpha-20251120235634-88fd4e9a4cbe3ef4792bdd0a808b897ac20ae425	npm ↗︎ unpkg ↗︎
@graphql-inspector/diff-command	6.0.4-alpha-20251120235634-88fd4e9a4cbe3ef4792bdd0a808b897ac20ae425	npm ↗︎ unpkg ↗︎
@graphql-inspector/introspect-command	5.0.16-alpha-20251120235634-88fd4e9a4cbe3ef4792bdd0a808b897ac20ae425	npm ↗︎ unpkg ↗︎
@graphql-inspector/similar-command	5.0.16-alpha-20251120235634-88fd4e9a4cbe3ef4792bdd0a808b897ac20ae425	npm ↗︎ unpkg ↗︎
@graphql-inspector/validate-command	5.0.16-alpha-20251120235634-88fd4e9a4cbe3ef4792bdd0a808b897ac20ae425	npm ↗︎ unpkg ↗︎
@graphql-inspector/core	7.1.0-alpha-20251120235634-88fd4e9a4cbe3ef4792bdd0a808b897ac20ae425	npm ↗︎ unpkg ↗︎

[jdolle]

Need to exclude these introspection types. Otherwise they'll show as "added" if null is passed as the oldSchema.

Before, both oldSchema and newSchema contained identical types and so no changes were output.

[n1ru4l]

Isn't unknown also a legit name that the root Query type could be named after? Maybe it should be null and not a string instead.

type unknown {
  foo: Int
}

schema {
  query: unknown
}