added support for snapshot#docChanges

agnostack · Feb 21, 2020 · 6ff3e34 · 6ff3e34
1 parent bd85b69
commit 6ff3e34
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Showing 4 changed files with 129 additions and 9 deletions.
diff --git a/package-lock.json b/package-lock.json
diff --git a/src/firestore-query-snapshot.js b/src/firestore-query-snapshot.js
@@ -3,7 +3,9 @@
 var _ = require('./lodash');
 var DocumentSnapshot = require('./firestore-document-snapshot');
 
-function MockFirestoreQuerySnapshot (ref, data) {
+function MockFirestoreQuerySnapshot (ref, data, priorData) {
+  var self = this;
+
   this._ref = ref;
   this.data = _.cloneDeep(data) || {};
   if (_.isObject(this.data) && _.isEmpty(this.data)) {
@@ -12,17 +14,46 @@ function MockFirestoreQuerySnapshot (ref, data) {
   this.size = _.size(this.data);
   this.empty = this.size === 0;
 
-  var self = this;
   this.docs = _.map(this.data, function (value, key) {
     return new DocumentSnapshot(key, self._ref.doc(key), value);
   });
+
+  var prior = priorData || {};
+  this._changes = _.reduce(
+    this.docs,
+    function(changes, doc) {      
+      if (!prior[doc.id]) changes.push({ type: "added", doc });
+      if (prior[doc.id] && !_.isEqual(doc.data(), prior[doc.id]))
+        changes.push({ type: "modified", doc });
+
+      return changes;
+    },
+    []
+  );
+
+  _.forEach(prior, function (value, key) {
+    if (!data[key]) self._changes.push({ 
+      type: 'removed', 
+      doc: new DocumentSnapshot(key, self._ref.doc(key), value) 
+    });
+  })
 }
 
-MockFirestoreQuerySnapshot.prototype.forEach = function (callback, context) {
-  var self = this;
-  _.forEach(this.docs, function (doc) {
+MockFirestoreQuerySnapshot.prototype.forEach = function(callback, context) {
+  _.forEach(this.docs, function(doc) {
     callback.call(context, doc);
   });
 };
 
+MockFirestoreQuerySnapshot.prototype.docChanges = function() {
+  var self = this;
+  return {
+    forEach: function(callback, context) {
+      _.forEach(self._changes, function(change) {
+        callback.call(context, change);
+      });
+    }
+  };
+};
+
 module.exports = MockFirestoreQuerySnapshot;
diff --git a/src/firestore-query.js b/src/firestore-query.js
@@ -208,22 +208,22 @@ MockFirestoreQuery.prototype.onSnapshot = function (optionsOrObserverOrOnNext, o
   var context = {
     data: self._results(),
   };
-  var onSnapshot = function (forceTrigger) {
+  var onSnapshot = function (initialCall) {
     // compare the current state to the one from when this function was created
     // and send the data to the callback if different.
     if (err === null) {
-      if (forceTrigger) {
+      if (initialCall) {
         const results = self._results();
         if (_.size(self.data) !== 0) {
-          onNext(new QuerySnapshot(self.parent === null ? self : self.parent.collection(self.id), results));
+          onNext(new QuerySnapshot(self.parent === null ? self : self.parent.collection(self.id), results, {}));
         } else {
           onNext(new QuerySnapshot(self.parent === null ? self : self.parent.collection(self.id)));
         }
       } else {
         self.get().then(function (querySnapshot) {
           var results = self._results();
           if (!_.isEqual(results, context.data) || includeMetadataChanges) {
-            onNext(new QuerySnapshot(self.parent === null ? self : self.parent.collection(self.id), results));
+            onNext(new QuerySnapshot(self.parent === null ? self : self.parent.collection(self.id), results, context.data));
             context.data = results;
           }
         });

diff --git a/test/unit/firestore-collection.js b/test/unit/firestore-collection.js
@@ -649,5 +649,84 @@ describe('MockFirestoreCollection', function () {
       collection.flush();
     });
 
+    describe('snapshot#docChange', () => {
+      beforeEach(function () {
+        db.collection('docChange').doc('123').set({ name: 'A' });
+        db.collection('docChange').doc('456').set({ name: 'B' });
+        db.collection('docChange').flush();
+      })
+
+      it('should initially provide all collection results as "added"', () => {        
+        db.collection('docChange').onSnapshot(function(snap) {
+          const changes = [];
+          snap
+            .docChanges()
+            .forEach(ch =>
+              changes.push({ type: ch.type, data: ch.doc.data() })
+            );
+
+          expect(changes).to.deep.equal([
+            { type: 'added', data: { name: 'A' } },
+            { type: 'added', data: { name: 'B' } }
+          ]);
+        });
+      });
+
+      it('should show subsequently changed data as "modified"', function(done) {        
+        let callCount = 0;
+        db.collection('docChange').onSnapshot(function(snap) {
+          try {
+            const changes = [];
+
+            if (callCount++ !== 1) return;
+
+            snap
+              .docChanges()
+              .forEach(ch =>
+                changes.push({ type: ch.type, data: ch.doc.data() })
+              );
+
+            expect(changes).to.deep.equal([
+              { type: 'modified', data: { name: 'AA' } },
+            ]);
+            done();
+          }
+          catch(e) {
+            done(e);
+          }
+        });
+
+        db.collection('docChange').doc('123').set({ name: 'AA' });
+        db.flush();        
+      });
+
+      it('should show subsequently removed data as "removed"', function(done) {        
+        let callCount = 0;
+        db.collection('docChange').onSnapshot(function(snap) {
+          try {
+            const changes = [];
+
+            if (callCount++ !== 1) return;
+
+            snap
+              .docChanges()
+              .forEach(ch =>
+                changes.push({ type: ch.type, data: ch.doc.data() })
+              );
+
+            expect(changes).to.deep.equal([
+              { type: 'removed', data: { name: 'A' } },
+            ]);
+            done();
+          }
+          catch(e) {
+            done(e);
+          }
+        });
+
+        db.collection('docChange').doc('123').delete();
+        db.flush();        
+      })
+    });
   });
 });