Merge pull request #26209 from overleaf/em-multiple-edit-ops

Support multiple ops in the history OT ShareJS type GitOrigin-RevId: fad1e9081ed1978de414c5130692d3b23fcd13d8
2025-06-10 08:06:13 +00:00
parent 5b08adc4ff
commit 6d202432ff
2 changed files with 169 additions and 4 deletions
@@ -0,0 +1,134 @@
+import { expect } from 'chai'
+import {
+  StringFileData,
+  TextOperation,
+  AddCommentOperation,
+  Range,
+} from 'overleaf-editor-core'
+import { historyOTType } from '@/features/ide-react/editor/share-js-history-ot-type'
+
+describe('historyOTType', function () {
+  let snapshot: StringFileData
+  let opsA: TextOperation[]
+  let opsB: TextOperation[]
+
+  beforeEach(function () {
+    snapshot = new StringFileData('one plus two equals three')
+
+    // After opsA: "seven plus five equals twelve"
+    opsA = [new TextOperation(), new TextOperation(), new TextOperation()]
+
+    opsA[0].remove(3)
+    opsA[0].insert('seven')
+    opsA[0].retain(22)
+
+    opsA[1].retain(11)
+    opsA[1].remove(3)
+    opsA[1].insert('five')
+    opsA[1].retain(13)
+
+    opsA[2].retain(23)
+    opsA[2].remove(5)
+    opsA[2].insert('twelve')
+
+    // After ops2: "one times two equals two"
+    opsB = [new TextOperation(), new TextOperation()]
+
+    opsB[0].retain(4)
+    opsB[0].remove(4)
+    opsB[0].insert('times')
+    opsB[0].retain(17)
+
+    opsB[1].retain(21)
+    opsB[1].remove(5)
+    opsB[1].insert('two')
+  })
+
+  describe('apply', function () {
+    it('supports an empty operations array', function () {
+      const result = historyOTType.apply(snapshot, [])
+      expect(result.getContent()).to.equal('one plus two equals three')
+    })
+
+    it('applies operations to the snapshot (opsA)', function () {
+      const result = historyOTType.apply(snapshot, opsA)
+      expect(result.getContent()).to.equal('seven plus five equals twelve')
+    })
+
+    it('applies operations to the snapshot (opsB)', function () {
+      const result = historyOTType.apply(snapshot, opsB)
+      expect(result.getContent()).to.equal('one times two equals two')
+    })
+  })
+
+  describe('compose', function () {
+    it('supports empty operations', function () {
+      const ops = historyOTType.compose([], [])
+      expect(ops).to.deep.equal([])
+    })
+
+    it('supports an empty operation on the left', function () {
+      const ops = historyOTType.compose([], opsA)
+      const result = historyOTType.apply(snapshot, ops)
+      expect(result.getContent()).to.equal('seven plus five equals twelve')
+    })
+
+    it('supports an empty operation on the right', function () {
+      const ops = historyOTType.compose(opsA, [])
+      const result = historyOTType.apply(snapshot, ops)
+      expect(result.getContent()).to.equal('seven plus five equals twelve')
+    })
+
+    it('supports operations on both sides', function () {
+      const ops = historyOTType.compose(opsA.slice(0, 2), opsA.slice(2))
+      const result = historyOTType.apply(snapshot, ops)
+      expect(ops.length).to.equal(1)
+      expect(result.getContent()).to.equal('seven plus five equals twelve')
+    })
+
+    it("supports operations that can't be composed", function () {
+      const comment = new AddCommentOperation('comment-id', [new Range(3, 10)])
+      const ops = historyOTType.compose(opsA.slice(0, 2), [
+        comment,
+        ...opsA.slice(2),
+      ])
+      expect(ops.length).to.equal(3)
+      const result = historyOTType.apply(snapshot, ops)
+      expect(result.getContent()).to.equal('seven plus five equals twelve')
+    })
+  })
+
+  describe('transformX', function () {
+    it('supports empty operations', function () {
+      const [aPrime, bPrime] = historyOTType.transformX([], [])
+      expect(aPrime).to.deep.equal([])
+      expect(bPrime).to.deep.equal([])
+    })
+
+    it('supports an empty operation on the left', function () {
+      const [aPrime, bPrime] = historyOTType.transformX([], opsB)
+      expect(aPrime).to.deep.equal([])
+      expect(bPrime).to.deep.equal(opsB)
+    })
+
+    it('supports an empty operation on the right', function () {
+      const [aPrime, bPrime] = historyOTType.transformX(opsA, [])
+      expect(aPrime).to.deep.equal(opsA)
+      expect(bPrime).to.deep.equal([])
+    })
+
+    it('supports operations on both sides (a then b)', function () {
+      const [, bPrime] = historyOTType.transformX(opsA, opsB)
+      const ops = historyOTType.compose(opsA, bPrime)
+      const result = historyOTType.apply(snapshot, ops)
+      expect(result.getContent()).to.equal('seven times five equals twelvetwo')
+    })
+
+    it('supports operations on both sides (b then a)', function () {
+      const [aPrime] = historyOTType.transformX(opsA, opsB)
+      const ops = historyOTType.compose(opsB, aPrime)
+      const result = historyOTType.apply(snapshot, ops)
+      expect(result.getContent()).to.equal('seven times five equals twelvetwo')
+    })
+  })
+})