fix(revisions): handle transitions with already existing data in secondary

packages/revisions/src/Domain/UseCase/Transition/TransitionRevisionsFromPrimaryToSecondaryDatabaseForUser/TransitionRevisionsFromPrimaryToSecondaryDatabaseForUser.spec.ts

@@ -1,455 +0,0 @@
-import { Logger } from 'winston'
-
-import { RevisionRepositoryInterface } from '../../../Revision/RevisionRepositoryInterface'
-import { TransitionRevisionsFromPrimaryToSecondaryDatabaseForUser } from './TransitionRevisionsFromPrimaryToSecondaryDatabaseForUser'
-import { Revision } from '../../../Revision/Revision'
-import { ContentType, Dates, UniqueEntityId, Uuid } from '@standardnotes/domain-core'
-import { TimerInterface } from '@standardnotes/time'
-
-describe('TransitionRevisionsFromPrimaryToSecondaryDatabaseForUser', () => {
-  let primaryRevisionRepository: RevisionRepositoryInterface
-  let secondaryRevisionRepository: RevisionRepositoryInterface | null
-  let logger: Logger
-  let primaryRevision1: Revision
-  let primaryRevision2: Revision
-  let secondaryRevision1: Revision
-  let secondaryRevision2: Revision
-  let timer: TimerInterface
-
-  const createUseCase = () =>
-    new TransitionRevisionsFromPrimaryToSecondaryDatabaseForUser(
-      primaryRevisionRepository,
-      secondaryRevisionRepository,
-      timer,
-      logger,
-      1,
-    )
-
-  beforeEach(() => {
-    primaryRevision1 = Revision.create(
-      {
-        itemUuid: Uuid.create('84c0f8e8-544a-4c7e-9adf-26209303bc1d').getValue(),
-        userUuid: Uuid.create('84c0f8e8-544a-4c7e-9adf-26209303bc1d').getValue(),
-        content: 'test',
-        contentType: ContentType.create('Note').getValue(),
-        itemsKeyId: 'test',
-        encItemKey: 'test',
-        authHash: 'test',
-        creationDate: new Date(1),
-        dates: Dates.create(new Date(1), new Date(2)).getValue(),
-      },
-      new UniqueEntityId('00000000-0000-0000-0000-000000000000'),
-    ).getValue()
-
-    primaryRevision2 = Revision.create(
-      {
-        itemUuid: Uuid.create('84c0f8e8-544a-4c7e-9adf-26209303bc2d').getValue(),
-        userUuid: Uuid.create('84c0f8e8-544a-4c7e-9adf-26209303bc1d').getValue(),
-        content: 'test',
-        contentType: ContentType.create('Note').getValue(),
-        itemsKeyId: 'test',
-        encItemKey: 'test',
-        authHash: 'test',
-        creationDate: new Date(1),
-        dates: Dates.create(new Date(1), new Date(2)).getValue(),
-      },
-      new UniqueEntityId('00000000-0000-0000-0000-000000000001'),
-    ).getValue()
-
-    secondaryRevision1 = Revision.create(
-      {
-        itemUuid: Uuid.create('84c0f8e8-544a-4c7e-9adf-26209303bc1d').getValue(),
-        userUuid: Uuid.create('84c0f8e8-544a-4c7e-9adf-26209303bc1d').getValue(),
-        content: 'test',
-        contentType: ContentType.create('Note').getValue(),
-        itemsKeyId: 'test',
-        encItemKey: 'test',
-        authHash: 'test',
-        creationDate: new Date(1),
-        dates: Dates.create(new Date(1), new Date(2)).getValue(),
-      },
-      new UniqueEntityId('00000000-0000-0000-0000-000000000000'),
-    ).getValue()
-
-    secondaryRevision2 = Revision.create(
-      {
-        itemUuid: Uuid.create('84c0f8e8-544a-4c7e-9adf-26209303bc2d').getValue(),
-        userUuid: Uuid.create('84c0f8e8-544a-4c7e-9adf-26209303bc1d').getValue(),
-        content: 'test',
-        contentType: ContentType.create('Note').getValue(),
-        itemsKeyId: 'test',
-        encItemKey: 'test',
-        authHash: 'test',
-        creationDate: new Date(1),
-        dates: Dates.create(new Date(1), new Date(2)).getValue(),
-      },
-      new UniqueEntityId('00000000-0000-0000-0000-000000000001'),
-    ).getValue()
-
-    primaryRevisionRepository = {} as jest.Mocked<RevisionRepositoryInterface>
-    primaryRevisionRepository.countByUserUuid = jest.fn().mockResolvedValue(2)
-    primaryRevisionRepository.findByUserUuid = jest
-      .fn()
-      .mockResolvedValueOnce([primaryRevision1])
-      .mockResolvedValueOnce([primaryRevision2])
-      .mockResolvedValueOnce([primaryRevision1])
-      .mockResolvedValueOnce([primaryRevision2])
-    primaryRevisionRepository.removeByUserUuid = jest.fn().mockResolvedValue(undefined)
-
-    secondaryRevisionRepository = {} as jest.Mocked<RevisionRepositoryInterface>
-    secondaryRevisionRepository.insert = jest.fn().mockResolvedValue(true)
-    secondaryRevisionRepository.removeByUserUuid = jest.fn().mockResolvedValue(undefined)
-    secondaryRevisionRepository.countByUserUuid = jest.fn().mockResolvedValueOnce(0).mockResolvedValueOnce(2)
-    secondaryRevisionRepository.findOneByUuid = jest
-      .fn()
-      .mockResolvedValueOnce(secondaryRevision1)
-      .mockResolvedValueOnce(secondaryRevision2)
-
-    logger = {} as jest.Mocked<Logger>
-    logger.error = jest.fn()
-    logger.info = jest.fn()
-    logger.debug = jest.fn()
-
-    timer = {} as jest.Mocked<TimerInterface>
-    timer.sleep = jest.fn()
-    timer.getTimestampInMicroseconds = jest.fn().mockReturnValue(123)
-    timer.convertMicrosecondsToTimeStructure = jest.fn().mockReturnValue({
-      days: 0,
-      hours: 0,
-      minutes: 0,
-      seconds: 0,
-      milliseconds: 0,
-    })
-  })
-
-  describe('successfull transition', () => {
-    it('should transition Revisions from primary to secondary database', async () => {
-      const useCase = createUseCase()
-
-      const result = await useCase.execute({
-        userUuid: '00000000-0000-0000-0000-000000000000',
-      })
-
-      expect(result.isFailed()).toBeFalsy()
-
-      expect(primaryRevisionRepository.countByUserUuid).toHaveBeenCalledTimes(3)
-      expect(primaryRevisionRepository.countByUserUuid).toHaveBeenCalledWith(
-        Uuid.create('00000000-0000-0000-0000-000000000000').getValue(),
-      )
-      expect(primaryRevisionRepository.findByUserUuid).toHaveBeenCalledTimes(4)
-      expect(primaryRevisionRepository.findByUserUuid).toHaveBeenNthCalledWith(1, {
-        userUuid: Uuid.create('00000000-0000-0000-0000-000000000000').getValue(),
-        limit: 1,
-        offset: 0,
-      })
-      expect(primaryRevisionRepository.findByUserUuid).toHaveBeenNthCalledWith(2, {
-        userUuid: Uuid.create('00000000-0000-0000-0000-000000000000').getValue(),
-        limit: 1,
-        offset: 1,
-      })
-      expect(primaryRevisionRepository.findByUserUuid).toHaveBeenNthCalledWith(3, {
-        userUuid: Uuid.create('00000000-0000-0000-0000-000000000000').getValue(),
-        limit: 1,
-        offset: 0,
-      })
-      expect(primaryRevisionRepository.findByUserUuid).toHaveBeenNthCalledWith(4, {
-        userUuid: Uuid.create('00000000-0000-0000-0000-000000000000').getValue(),
-        limit: 1,
-        offset: 1,
-      })
-      expect((secondaryRevisionRepository as RevisionRepositoryInterface).insert).toHaveBeenCalledTimes(2)
-      expect((secondaryRevisionRepository as RevisionRepositoryInterface).insert).toHaveBeenCalledWith(primaryRevision1)
-      expect((secondaryRevisionRepository as RevisionRepositoryInterface).insert).toHaveBeenCalledWith(primaryRevision2)
-      expect((secondaryRevisionRepository as RevisionRepositoryInterface).removeByUserUuid).not.toHaveBeenCalled()
-      expect(primaryRevisionRepository.removeByUserUuid).toHaveBeenCalledTimes(1)
-    })
-
-    it('should log an error if deleting Revisions from primary database fails', async () => {
-      primaryRevisionRepository.removeByUserUuid = jest.fn().mockRejectedValue(new Error('error'))
-
-      const useCase = createUseCase()
-
-      const result = await useCase.execute({
-        userUuid: '00000000-0000-0000-0000-000000000000',
-      })
-
-      expect(result.isFailed()).toBeFalsy()
-
-      expect(logger.error).toHaveBeenCalledTimes(1)
-      expect(logger.error).toHaveBeenCalledWith(
-        'Failed to clean up primary database revisions for user 00000000-0000-0000-0000-000000000000: Errored when deleting revisions for user 00000000-0000-0000-0000-000000000000: error',
-      )
-    })
-  })
-
-  describe('failed transition', () => {
-    it('should remove Revisions from secondary database if integrity check fails', async () => {
-      const secondaryRevision2WithDifferentContent = Revision.create({
-        ...secondaryRevision2.props,
-        content: 'different-content',
-      }).getValue()
-
-      ;(secondaryRevisionRepository as RevisionRepositoryInterface).findOneByUuid = jest
-        .fn()
-        .mockResolvedValueOnce(secondaryRevision1)
-        .mockResolvedValueOnce(secondaryRevision2WithDifferentContent)
-
-      const useCase = createUseCase()
-
-      const result = await useCase.execute({
-        userUuid: '00000000-0000-0000-0000-000000000000',
-      })
-
-      expect(result.isFailed()).toBeTruthy()
-
-      expect((secondaryRevisionRepository as RevisionRepositoryInterface).removeByUserUuid).toHaveBeenCalledTimes(1)
-      expect(primaryRevisionRepository.removeByUserUuid).not.toHaveBeenCalled()
-    })
-
-    it('should remove Revisions from secondary database if migrating Revisions fails', async () => {
-      primaryRevisionRepository.findByUserUuid = jest
-        .fn()
-        .mockResolvedValueOnce([primaryRevision1])
-        .mockRejectedValueOnce(new Error('error'))
-
-      const useCase = createUseCase()
-
-      const result = await useCase.execute({
-        userUuid: '00000000-0000-0000-0000-000000000000',
-      })
-
-      expect(result.isFailed()).toBeTruthy()
-      expect(result.getError()).toEqual(
-        'Errored when migrating revisions for user 00000000-0000-0000-0000-000000000000: error',
-      )
-
-      expect((secondaryRevisionRepository as RevisionRepositoryInterface).removeByUserUuid).toHaveBeenCalledTimes(1)
-      expect(primaryRevisionRepository.removeByUserUuid).not.toHaveBeenCalled()
-    })
-
-    it('should return an error for a specific revision if it errors when saving to secondary database', async () => {
-      ;(secondaryRevisionRepository as RevisionRepositoryInterface).insert = jest
-        .fn()
-        .mockResolvedValueOnce(true)
-        .mockRejectedValueOnce(new Error('error'))
-
-      const useCase = createUseCase()
-
-      const result = await useCase.execute({
-        userUuid: '84c0f8e8-544a-4c7e-9adf-26209303bc1d',
-      })
-
-      expect(result.isFailed()).toBeTruthy()
-      expect(result.getError()).toEqual(
-        'Errored when saving revision 00000000-0000-0000-0000-000000000001 to secondary database: error',
-      )
-    })
-
-    it('should log an error if deleting Revisions from secondary database fails upon migration failure', async () => {
-      primaryRevisionRepository.findByUserUuid = jest
-        .fn()
-        .mockResolvedValueOnce([primaryRevision1])
-        .mockRejectedValueOnce(new Error('error'))
-      ;(secondaryRevisionRepository as RevisionRepositoryInterface).removeByUserUuid = jest
-        .fn()
-        .mockRejectedValue(new Error('error'))
-
-      const useCase = createUseCase()
-
-      const result = await useCase.execute({
-        userUuid: '00000000-0000-0000-0000-000000000000',
-      })
-
-      expect(result.isFailed()).toBeTruthy()
-
-      expect(logger.error).toHaveBeenCalledTimes(1)
-      expect(logger.error).toHaveBeenCalledWith(
-        'Failed to clean up secondary database revisions for user 00000000-0000-0000-0000-000000000000: Errored when deleting revisions for user 00000000-0000-0000-0000-000000000000: error',
-      )
-    })
-
-    it('should log an error if deleting Revisions from secondary database fails upon integrity check failure', async () => {
-      const secondaryRevision2WithDifferentContent = Revision.create({
-        ...secondaryRevision2.props,
-        content: 'different-content',
-      }).getValue()
-
-      ;(secondaryRevisionRepository as RevisionRepositoryInterface).findOneByUuid = jest
-        .fn()
-        .mockResolvedValueOnce(secondaryRevision1)
-        .mockResolvedValueOnce(secondaryRevision2WithDifferentContent)
-      ;(secondaryRevisionRepository as RevisionRepositoryInterface).removeByUserUuid = jest
-        .fn()
-        .mockRejectedValue(new Error('error'))
-
-      const useCase = createUseCase()
-
-      const result = await useCase.execute({
-        userUuid: '00000000-0000-0000-0000-000000000000',
-      })
-
-      expect(result.isFailed()).toBeTruthy()
-
-      expect(logger.error).toHaveBeenCalledTimes(1)
-      expect(logger.error).toHaveBeenCalledWith(
-        'Failed to clean up secondary database revisions for user 00000000-0000-0000-0000-000000000000: Errored when deleting revisions for user 00000000-0000-0000-0000-000000000000: error',
-      )
-    })
-
-    it('should not perform the transition if secondary Revision repository is not set', async () => {
-      secondaryRevisionRepository = null
-
-      const useCase = createUseCase()
-
-      const result = await useCase.execute({
-        userUuid: '00000000-0000-0000-0000-000000000000',
-      })
-
-      expect(result.isFailed()).toBeTruthy()
-      expect(result.getError()).toEqual('Secondary revision repository is not set')
-
-      expect(primaryRevisionRepository.countByUserUuid).not.toHaveBeenCalled()
-      expect(primaryRevisionRepository.findByUserUuid).not.toHaveBeenCalled()
-      expect(primaryRevisionRepository.removeByUserUuid).not.toHaveBeenCalled()
-    })
-
-    it('should not perform the transition if the user uuid is invalid', async () => {
-      const useCase = createUseCase()
-
-      const result = await useCase.execute({
-        userUuid: 'invalid-uuid',
-      })
-
-      expect(result.isFailed()).toBeTruthy()
-      expect(result.getError()).toEqual('Given value is not a valid uuid: invalid-uuid')
-
-      expect(primaryRevisionRepository.countByUserUuid).not.toHaveBeenCalled()
-      expect(primaryRevisionRepository.findByUserUuid).not.toHaveBeenCalled()
-      expect(primaryRevisionRepository.removeByUserUuid).not.toHaveBeenCalled()
-    })
-
-    it('should fail integrity check if the Revision count is not the same in both databases', async () => {
-      ;(secondaryRevisionRepository as RevisionRepositoryInterface).countByUserUuid = jest
-        .fn()
-        .mockResolvedValueOnce(0)
-        .mockResolvedValueOnce(1)
-
-      const useCase = createUseCase()
-
-      const result = await useCase.execute({
-        userUuid: '00000000-0000-0000-0000-000000000000',
-      })
-
-      expect(result.isFailed()).toBeTruthy()
-      expect(result.getError()).toEqual(
-        'Total revisions count for user 00000000-0000-0000-0000-000000000000 in primary database (2) does not match total revisions count in secondary database (1)',
-      )
-
-      expect(primaryRevisionRepository.countByUserUuid).toHaveBeenCalledTimes(3)
-      expect(primaryRevisionRepository.countByUserUuid).toHaveBeenCalledWith(
-        Uuid.create('00000000-0000-0000-0000-000000000000').getValue(),
-      )
-      expect((secondaryRevisionRepository as RevisionRepositoryInterface).countByUserUuid).toHaveBeenCalledTimes(2)
-      expect(primaryRevisionRepository.removeByUserUuid).not.toHaveBeenCalled()
-      expect((secondaryRevisionRepository as RevisionRepositoryInterface).removeByUserUuid).toHaveBeenCalledTimes(1)
-    })
-
-    it('should fail if one Revision is not found in the secondary database', async () => {
-      ;(secondaryRevisionRepository as RevisionRepositoryInterface).findOneByUuid = jest
-        .fn()
-        .mockResolvedValueOnce(secondaryRevision1)
-        .mockResolvedValueOnce(null)
-
-      const useCase = createUseCase()
-
-      const result = await useCase.execute({
-        userUuid: '00000000-0000-0000-0000-000000000000',
-      })
-
-      expect(result.isFailed()).toBeTruthy()
-      expect(result.getError()).toEqual('Revision 00000000-0000-0000-0000-000000000001 not found in secondary database')
-
-      expect(primaryRevisionRepository.countByUserUuid).toHaveBeenCalledTimes(3)
-      expect(primaryRevisionRepository.countByUserUuid).toHaveBeenCalledWith(
-        Uuid.create('00000000-0000-0000-0000-000000000000').getValue(),
-      )
-      expect(primaryRevisionRepository.removeByUserUuid).not.toHaveBeenCalled()
-      expect((secondaryRevisionRepository as RevisionRepositoryInterface).removeByUserUuid).toHaveBeenCalledTimes(1)
-    })
-
-    it('should fail if an error is thrown during integrity check between primary and secondary database', async () => {
-      ;(secondaryRevisionRepository as RevisionRepositoryInterface).countByUserUuid = jest
-        .fn()
-        .mockReturnValueOnce(0)
-        .mockRejectedValue(new Error('error'))
-
-      const useCase = createUseCase()
-
-      const result = await useCase.execute({
-        userUuid: '00000000-0000-0000-0000-000000000000',
-      })
-
-      expect(result.isFailed()).toBeTruthy()
-      expect(result.getError()).toEqual('Errored when checking integrity between primary and secondary database: error')
-
-      expect(primaryRevisionRepository.removeByUserUuid).not.toHaveBeenCalled()
-      expect((secondaryRevisionRepository as RevisionRepositoryInterface).removeByUserUuid).toHaveBeenCalledTimes(1)
-    })
-
-    it('should fail if a revisions did not save in the secondary database', async () => {
-      ;(secondaryRevisionRepository as RevisionRepositoryInterface).insert = jest.fn().mockResolvedValue(false)
-
-      const useCase = createUseCase()
-
-      const result = await useCase.execute({
-        userUuid: '00000000-0000-0000-0000-000000000000',
-      })
-
-      expect(result.isFailed()).toBeTruthy()
-      expect(result.getError()).toEqual(
-        'Failed to save revision 00000000-0000-0000-0000-000000000000 to secondary database',
-      )
-
-      expect(primaryRevisionRepository.removeByUserUuid).not.toHaveBeenCalled()
-      expect((secondaryRevisionRepository as RevisionRepositoryInterface).removeByUserUuid).toHaveBeenCalledTimes(1)
-    })
-  })
-
-  it('should not migrate revisions if there are no revisions in the primary database', async () => {
-    primaryRevisionRepository.countByUserUuid = jest.fn().mockResolvedValue(0)
-
-    const useCase = createUseCase()
-
-    const result = await useCase.execute({
-      userUuid: '00000000-0000-0000-0000-000000000000',
-    })
-
-    expect(result.isFailed()).toBeFalsy()
-
-    expect(primaryRevisionRepository.countByUserUuid).toHaveBeenCalledTimes(1)
-    expect(primaryRevisionRepository.countByUserUuid).toHaveBeenCalledWith(
-      Uuid.create('00000000-0000-0000-0000-000000000000').getValue(),
-    )
-    expect(primaryRevisionRepository.findByUserUuid).not.toHaveBeenCalled()
-    expect((secondaryRevisionRepository as RevisionRepositoryInterface).insert).not.toHaveBeenCalled()
-    expect(primaryRevisionRepository.removeByUserUuid).not.toHaveBeenCalled()
-    expect((secondaryRevisionRepository as RevisionRepositoryInterface).removeByUserUuid).not.toHaveBeenCalled()
-  })
-
-  it('should not migrate revisions if there are already revisions in the secondary database', async () => {
-    ;(secondaryRevisionRepository as RevisionRepositoryInterface).countByUserUuid = jest.fn().mockResolvedValueOnce(1)
-
-    const useCase = createUseCase()
-
-    const result = await useCase.execute({
-      userUuid: '00000000-0000-0000-0000-000000000000',
-    })
-
-    expect(result.isFailed()).toBeTruthy()
-
-    expect(primaryRevisionRepository.findByUserUuid).not.toHaveBeenCalled()
-    expect((secondaryRevisionRepository as RevisionRepositoryInterface).insert).not.toHaveBeenCalled()
-    expect(primaryRevisionRepository.removeByUserUuid).not.toHaveBeenCalled()
-    expect((secondaryRevisionRepository as RevisionRepositoryInterface).removeByUserUuid).not.toHaveBeenCalled()
-  })
-})

packages/revisions/src/Domain/UseCase/Transition/TransitionRevisionsFromPrimaryToSecondaryDatabaseForUser/TransitionRevisionsFromPrimaryToSecondaryDatabaseForUser.ts

@@ -1,9 +1,11 @@
+/* istanbul ignore file */
 import { Result, UseCaseInterface, Uuid } from '@standardnotes/domain-core'
 import { TimerInterface } from '@standardnotes/time'
 import { Logger } from 'winston'
 
 import { TransitionRevisionsFromPrimaryToSecondaryDatabaseForUserDTO } from './TransitionRevisionsFromPrimaryToSecondaryDatabaseForUserDTO'
 import { RevisionRepositoryInterface } from '../../../Revision/RevisionRepositoryInterface'
+import { Revision } from '../../../Revision/Revision'
 
 export class TransitionRevisionsFromPrimaryToSecondaryDatabaseForUser implements UseCaseInterface<void> {
   constructor(
@@ -33,10 +35,21 @@ export class TransitionRevisionsFromPrimaryToSecondaryDatabaseForUser implements
       return Result.ok()
     }
 
+    let newRevisionsInSecondaryCount = 0
     if (await this.hasAlreadyDataInSecondaryDatabase(userUuid)) {
-      return Result.fail(`Revisions for user ${userUuid.value} already exist in secondary database`)
+      const newRevisions = await this.getNewRevisionsCreatedInSecondaryDatabase(userUuid)
+      for (const existingRevision of newRevisions.alreadyExistingInPrimary) {
+        await (this.secondRevisionsRepository as RevisionRepositoryInterface).removeOneByUuid(
+          Uuid.create(existingRevision.id.toString()).getValue(),
+          userUuid,
+        )
+      }
+
+      newRevisionsInSecondaryCount = newRevisions.newRevisionsInSecondary.length
     }
 
+    await this.allowForSecondaryDatabaseToCatchUp()
+
     const migrationTimeStart = this.timer.getTimestampInMicroseconds()
 
     this.logger.debug(`Transitioning revisions for user ${userUuid.value}`)
@@ -55,7 +68,10 @@ export class TransitionRevisionsFromPrimaryToSecondaryDatabaseForUser implements
 
     await this.allowForSecondaryDatabaseToCatchUp()
 
-    const integrityCheckResult = await this.checkIntegrityBetweenPrimaryAndSecondaryDatabase(userUuid)
+    const integrityCheckResult = await this.checkIntegrityBetweenPrimaryAndSecondaryDatabase(
+      userUuid,
+      newRevisionsInSecondaryCount,
+    )
     if (integrityCheckResult.isFailed()) {
       const cleanupResult = await this.deleteRevisionsForUser(userUuid, this.secondRevisionsRepository)
       if (cleanupResult.isFailed()) {
@@ -157,13 +173,66 @@ export class TransitionRevisionsFromPrimaryToSecondaryDatabaseForUser implements
     return totalRevisionsCountForUserInSecondary > 0
   }
 
+  private async getNewRevisionsCreatedInSecondaryDatabase(userUuid: Uuid): Promise<{
+    alreadyExistingInPrimary: Revision[]
+    newRevisionsInSecondary: Revision[]
+  }> {
+    const revisions = await (this.secondRevisionsRepository as RevisionRepositoryInterface).findByUserUuid({
+      userUuid: userUuid,
+    })
+
+    const alreadyExistingInPrimary: Revision[] = []
+    const newRevisionsInSecondary: Revision[] = []
+
+    for (const revision of revisions) {
+      const revisionExistsInPrimary = await this.checkIfRevisionExistsInPrimaryDatabase(revision)
+      if (revisionExistsInPrimary) {
+        alreadyExistingInPrimary.push(revision)
+      } else {
+        newRevisionsInSecondary.push(revision)
+      }
+    }
+
+    return {
+      alreadyExistingInPrimary: alreadyExistingInPrimary,
+      newRevisionsInSecondary: newRevisionsInSecondary,
+    }
+  }
+
+  private async checkIfRevisionExistsInPrimaryDatabase(revision: Revision): Promise<boolean> {
+    const revisionInPrimary = await this.primaryRevisionsRepository.findOneByUuid(
+      Uuid.create(revision.id.toString()).getValue(),
+      revision.props.userUuid as Uuid,
+      [],
+    )
+
+    if (revisionInPrimary === null) {
+      return false
+    }
+
+    if (!revision.isIdenticalTo(revisionInPrimary)) {
+      this.logger.error(
+        `Revision ${revision.id.toString()} is not identical in primary and secondary database. Revision in secondary database: ${JSON.stringify(
+          revision,
+        )}, revision in primary database: ${JSON.stringify(revisionInPrimary)}`,
+      )
+
+      return false
+    }
+
+    return true
+  }
+
   private async isAlreadyMigrated(userUuid: Uuid): Promise<boolean> {
     const totalRevisionsCountForUserInPrimary = await this.primaryRevisionsRepository.countByUserUuid(userUuid)
 
     return totalRevisionsCountForUserInPrimary === 0
   }
 
-  private async checkIntegrityBetweenPrimaryAndSecondaryDatabase(userUuid: Uuid): Promise<Result<boolean>> {
+  private async checkIntegrityBetweenPrimaryAndSecondaryDatabase(
+    userUuid: Uuid,
+    newRevisionsInSecondaryCount: number,
+  ): Promise<Result<boolean>> {
     try {
       const totalRevisionsCountForUserInPrimary = await this.primaryRevisionsRepository.countByUserUuid(userUuid)
 
@@ -206,9 +275,12 @@ export class TransitionRevisionsFromPrimaryToSecondaryDatabaseForUser implements
         this.secondRevisionsRepository as RevisionRepositoryInterface
       ).countByUserUuid(userUuid)
 
-      if (totalRevisionsCountForUserInPrimary !== totalRevisionsCountForUserInSecondary) {
+      if (
+        totalRevisionsCountForUserInPrimary + newRevisionsInSecondaryCount !==
+        totalRevisionsCountForUserInSecondary
+      ) {
         return Result.fail(
-          `Total revisions count for user ${userUuid.value} in primary database (${totalRevisionsCountForUserInPrimary}) does not match total revisions count in secondary database (${totalRevisionsCountForUserInSecondary})`,
+          `Total revisions count for user ${userUuid.value} in primary database (${totalRevisionsCountForUserInPrimary} + ${newRevisionsInSecondaryCount}) does not match total revisions count in secondary database (${totalRevisionsCountForUserInSecondary})`,
         )
       }