Add checkpoint events during replication

.eslintrc.json

@@ -3,7 +3,7 @@
   "extends": "eslint:recommended",
 
   "parserOptions": {
-    "ecmaVersion": 6,
+    "ecmaVersion": 8,
     "sourceType": "module"
   },
 

packages/node_modules/pouchdb-replication/src/replicate.js

@@ -132,6 +132,7 @@ function replicate(src, target, opts, returnValue, result) {
     writingCheckpoint = true;
     return checkpointer.writeCheckpoint(currentBatch.seq,
         session).then(function () {
+      returnValue.emit('checkpoint', { 'checkpoint': currentBatch.seq });
       writingCheckpoint = false;
       /* istanbul ignore if */
       if (returnValue.cancelled) {
@@ -149,6 +150,7 @@ function replicate(src, target, opts, returnValue, result) {
   function getDiffs() {
     var diff = {};
     currentBatch.changes.forEach(function (change) {
+      returnValue.emit('checkpoint', { 'revs_diff': change });
       // Couchbase Sync Gateway emits these, but we can ignore them
       /* istanbul ignore if */
       if (change.id === "_user/") {
@@ -189,6 +191,7 @@ function replicate(src, target, opts, returnValue, result) {
       return;
     }
     currentBatch = batches.shift();
+    returnValue.emit('checkpoint', { 'start_next_batch': currentBatch.seq });
     getDiffs()
       .then(getBatchDocs)
       .then(writeDocs)
@@ -307,6 +310,7 @@ function replicate(src, target, opts, returnValue, result) {
     }
     pendingBatch.seq = change.seq || lastSeq;
     pendingBatch.changes.push(change);
+    returnValue.emit('checkpoint', { 'pending_batch': pendingBatch.seq });
     nextTick(function () {
       processPendingBatch(batches.length === 0 && changesOpts.live);
     });

tests/integration/test.replication_events.js

@@ -400,5 +400,37 @@ adapters.forEach(function (adapters) {
     // #5607 https://github.com/pouchdb/pouchdb/issues/5607#issuecomment-346078688
     // Note: Uppercase 'Unauthorized' response
     describe('#5607 handle uppercase third-party error responses', replication401TestFunction('Unauthorized'));
+
+    it('Test checkpoint events', async () => {
+      const docs = {
+        docs: [
+          {_id: '0', integer: 0, string: '0'},
+          {_id: '1', integer: 1, string: '1'},
+          {_id: '2', integer: 2, string: '2'},
+        ],
+      };
+      const remote = new PouchDB(dbs.remote);
+      const checkpointEvents = [];
+
+      await remote.bulkDocs(docs, {});
+      const replication = PouchDB.replicate(dbs.remote, dbs.name, {});
+      replication.on('checkpoint', result => checkpointEvents.push(result));
+      await replication;
+
+      checkpointEvents[0]['pending_batch'].should.equal(1);
+      checkpointEvents[1]['pending_batch'].should.equal(2);
+      checkpointEvents[2]['pending_batch'].should.equal(3);
+      checkpointEvents[3]['start_next_batch'].should.equal(3);
+      checkpointEvents[4]['revs_diff'].should.have.property('id');
+      checkpointEvents[4]['revs_diff']['id'].should.equal('0');
+      checkpointEvents[4]['revs_diff']['seq'].should.equal(1);
+      checkpointEvents[5]['revs_diff'].should.have.property('changes');
+      checkpointEvents[5]['revs_diff']['id'].should.equal('1');
+      checkpointEvents[5]['revs_diff']['seq'].should.equal(2);
+      checkpointEvents[6]['revs_diff'].should.have.property('changes');
+      checkpointEvents[6]['revs_diff']['id'].should.equal('2');
+      checkpointEvents[6]['revs_diff']['seq'].should.equal(3);
+      checkpointEvents[7]['checkpoint'].should.equal(3);
+    });
   });
 });