[Migrations] Upgrade tests to use 9.x compatible archives (#193696)

## Summary

Part of elastic/kibana-team#1113

Merges some tested code paths into `v2_migration.test.ts` which uses an
archive that is generated in 9.0.0.
Gets rid of the related failing tests.

docs/setup/upgrade/resolving-migration-failures.asciidoc

@@ -120,10 +120,7 @@ If you fail to remedy this, your upgrade to 8.0+ will fail with a message like:
 
 [source,sh]
 --------------------------------------------
-Unable to complete saved object migrations for the [.kibana] index: Migration failed because some documents were found which use unknown saved object types:
-- "firstDocId" (type "someType")
-- "secondtDocId" (type "someType")
-- "thirdDocId" (type "someOtherType")
+Unable to complete saved object migrations for the [.kibana] index: Migration failed because some documents were found which use unknown saved object types: someType,someOtherType
 
 To proceed with the migration you can configure Kibana to discard unknown saved objects for this migration.
 --------------------------------------------

packages/core/saved-objects/core-saved-objects-migration-server-internal/src/model/extract_errors.test.ts

@@ -29,10 +29,7 @@ describe('extractUnknownDocFailureReason', () => {
         },
       ])
     ).toMatchInlineSnapshot(`
-      "Migration failed because some documents were found which use unknown saved object types:
-      - \\"unknownType:12\\" (type: \\"unknownType\\")
-      - \\"anotherUnknownType:42\\" (type: \\"anotherUnknownType\\")
-
+      "Migration failed because some documents were found which use unknown saved object types: unknownType,anotherUnknownType
       To proceed with the migration you can configure Kibana to discard unknown saved objects for this migration.
       Please refer to some-url.co for more information."
     `);

packages/core/saved-objects/core-saved-objects-migration-server-internal/src/model/extract_errors.ts

@@ -52,10 +52,12 @@ export function extractUnknownDocFailureReason(
   resolveMigrationFailuresUrl: string,
   unknownDocs: DocumentIdAndType[]
 ): string {
+  const typesSet = new Set(unknownDocs.map(({ type }) => type));
   return (
-    `Migration failed because some documents were found which use unknown saved object types:\n` +
-    unknownDocs.map((doc) => `- "${doc.id}" (type: "${doc.type}")\n`).join('') +
-    `\nTo proceed with the migration you can configure Kibana to discard unknown saved objects for this migration.\n` +
+    `Migration failed because some documents were found which use unknown saved object types: ${Array.from(
+      typesSet.values()
+    )}\n` +
+    `To proceed with the migration you can configure Kibana to discard unknown saved objects for this migration.\n` +
     `Please refer to ${resolveMigrationFailuresUrl} for more information.`
   );
 }

packages/core/saved-objects/core-saved-objects-migration-server-internal/src/model/model.ts

@@ -559,13 +559,21 @@ export const model = (currentState: State, resW: ResponseType<AllActionStates>):
         deleteByQueryTaskId: res.right.taskId,
       };
     } else {
+      const reason = extractUnknownDocFailureReason(
+        stateP.migrationDocLinks.resolveMigrationFailures,
+        res.left.unknownDocs
+      );
       return {
         ...stateP,
         controlState: 'FATAL',
-        reason: extractUnknownDocFailureReason(
-          stateP.migrationDocLinks.resolveMigrationFailures,
-          res.left.unknownDocs
-        ),
+        reason,
+        logs: [
+          ...logs,
+          {
+            level: 'error',
+            message: reason,
+          },
+        ],
       };
     }
   } else if (stateP.controlState === 'CLEANUP_UNKNOWN_AND_EXCLUDED_WAIT_FOR_TASK') {
@@ -700,13 +708,22 @@ export const model = (currentState: State, resW: ResponseType<AllActionStates>):
 
     if (isTypeof(res.right, 'unknown_docs_found')) {
       if (!stateP.discardUnknownObjects) {
+        const reason = extractUnknownDocFailureReason(
+          stateP.migrationDocLinks.resolveMigrationFailures,
+          res.right.unknownDocs
+        );
+
         return {
           ...stateP,
           controlState: 'FATAL',
-          reason: extractUnknownDocFailureReason(
-            stateP.migrationDocLinks.resolveMigrationFailures,
-            res.right.unknownDocs
-          ),
+          reason,
+          logs: [
+            ...logs,
+            {
+              level: 'error',
+              message: reason,
+            },
+          ],
         };
       }
 
@@ -879,6 +896,13 @@ export const model = (currentState: State, resW: ResponseType<AllActionStates>):
         corruptDocumentIds: [],
         transformErrors: [],
         progress: createInitialProgress(),
+        logs: [
+          ...logs,
+          {
+            level: 'info',
+            message: `REINDEX_SOURCE_TO_TEMP_OPEN_PIT PitId:${res.right.pitId}`,
+          },
+        ],
       };
     } else {
       throwBadResponse(stateP, res);