Merge branch 'main' into endpoints-not-models

Author: davidkyle

compiler/src/steps/validate-model.ts

@@ -21,6 +21,7 @@ import * as model from '../model/metamodel'
 import { ValidationErrors } from '../validation-errors'
 import { JsonSpec } from '../model/json-spec'
 import assert from 'assert'
+import { TypeName } from '../model/metamodel'
 
 // Superclasses (i.e. non-leaf types, who are inherited or implemented) that are ok to be used as field types because
 // they're used as definition reuse and not as polymorphic types.
@@ -170,8 +171,14 @@ export default async function validateModel (apiModel: model.Model, restSpec: Ma
     })
   }
 
-  // ErrorResponse is not referenced anywhere, but any API could return it if an error happens.
-  validateTypeRef({ namespace: '_types', name: 'ErrorResponseBase' }, undefined, new Set())
+  const additionalRoots: TypeName[] = [
+    // ErrorResponse is not referenced anywhere, but any API could return it if an error happens.
+    { namespace: '_types', name: 'ErrorResponseBase' },
+    // ESQL base versions are pseudo-constants
+    { namespace: 'esql._types', name: 'BaseStatefulEsqlVersion' },
+    { namespace: 'esql._types', name: 'BaseServerlessEsqlVersion' }
+  ]
+  additionalRoots.forEach(t => validateTypeRef(t, undefined, new Set()))
 
   // -----  Alright, let's go!