Merge pull request #12229 from overleaf/jpa-reject-decrement-doc-version

[docstore] reject doc updates that decrement the doc version

GitOrigin-RevId: 533cc5ece8d5684c85b2f63fa2a093c68f6b5877

services/docstore/test/acceptance/js/UpdatingDocsTests.js

@@ -179,6 +179,43 @@ describe('Applying updates to a doc', function () {
     })
   })
 
+  describe('when the version was decremented', function () {
+    beforeEach(function (done) {
+      DocstoreClient.updateDoc(
+        this.project_id,
+        this.doc_id,
+        this.newLines,
+        this.version - 1,
+        this.newRanges,
+        (error, res, body) => {
+          if (error) return done(error)
+          this.res = res
+          this.body = body
+          done()
+        }
+      )
+    })
+
+    it('should return 409', function () {
+      this.res.statusCode.should.equal(409)
+    })
+
+    it('should not update the doc in the API', function (done) {
+      DocstoreClient.getDoc(
+        this.project_id,
+        this.doc_id,
+        {},
+        (error, res, doc) => {
+          if (error) return done(error)
+          doc.lines.should.deep.equal(this.originalLines)
+          doc.version.should.equal(this.version)
+          doc.ranges.should.deep.equal(this.originalRanges)
+          done()
+        }
+      )
+    })
+  })
+
   describe('when the ranges have changed', function () {
     beforeEach(function (done) {
       return DocstoreClient.updateDoc(

services/docstore/test/unit/js/DocManagerTests.js

@@ -796,6 +796,26 @@ describe('DocManager', function () {
       })
     })
 
+    describe('when the version was decremented', function () {
+      beforeEach(function () {
+        this.DocManager._getDoc = sinon.stub().yields(null, this.doc)
+        this.DocManager.updateDoc(
+          this.project_id,
+          this.doc_id,
+          this.newDocLines,
+          this.version - 1,
+          this.originalRanges,
+          this.callback
+        )
+      })
+
+      it('should return an error', function () {
+        this.callback.should.have.been.calledWith(
+          sinon.match.instanceOf(Errors.DocVersionDecrementedError)
+        )
+      })
+    })
+
     describe('when the doc lines have not changed', function () {
       beforeEach(function () {
         this.DocManager._getDoc = sinon.stub().callsArgWith(3, null, this.doc)