add reset of the same ip votes on -+ or +- changes and move same ip set and reject check up (above this reset)

backend/app/store/service/service.go

@@ -315,7 +315,7 @@ func (s *DataStore) Vote(req VoteReq) (comment store.Comment, err error) {
 	}
 
 	v, voted := comment.Votes[req.UserID]
-	if voted && v == req.Val {
+	if voted && v == req.Val { // voted before and same vote (+/-) again. Change allowed, i.e. +, - or -, + is fine
 		return comment, errors.Errorf("user %s already voted for %s", req.UserID, req.CommentID)
 	}
 
@@ -341,9 +341,16 @@ func (s *DataStore) Vote(req VoteReq) (comment store.Comment, err error) {
 		return comment, errors.Errorf("minimal score reached for comment %s", req.CommentID)
 	}
 
-	// reset vote if user changed to opposite
+	// add ip hash to voted ip map
+	if comment.VotedIPs == nil {
+		comment.VotedIPs = map[string]store.VotedIPInfo{}
+	}
+	comment.VotedIPs[userIPHash] = store.VotedIPInfo{Timestamp: time.Now(), Value: req.Val}
+
+	// reset vote if user changed to opposite. Effectively it is "forget about prev votes" to allow "+ - -" or "- + +" corrections
 	if voted && v != req.Val {
 		delete(comment.Votes, req.UserID)
+		delete(comment.VotedIPs, userIPHash)
 	}
 
 	// add to voted map if first vote
@@ -351,13 +358,6 @@ func (s *DataStore) Vote(req VoteReq) (comment store.Comment, err error) {
 		comment.Votes[req.UserID] = req.Val
 	}
 
-	// add ip hash to voted ip map
-	if comment.VotedIPs == nil {
-		comment.VotedIPs = map[string]store.VotedIPInfo{}
-	}
-
-	comment.VotedIPs[userIPHash] = store.VotedIPInfo{Timestamp: time.Now(), Value: req.Val}
-
 	// update score
 	if req.Val {
 		comment.Score++

backend/app/store/service/service_test.go

@@ -455,7 +455,29 @@ func TestService_VotePositive(t *testing.T) {
 	assert.NoError(t, err, "minimal score doesn't affect positive vote")
 	assert.Equal(t, 1, c.Score)
 
-	b.PositiveScore = false // allow negative voting
+	c, err = b.Vote(VoteReq{Locator: store.Locator{URL: "https://radio-t.com", SiteID: "radio-t"}, CommentID: "id-1",
+		UserID: "user2", Val: true})
+	assert.NoError(t, err, "vote set to +2")
+	assert.Equal(t, 2, c.Score)
+
+	// check +, -, -
+	c, err = b.Vote(VoteReq{Locator: store.Locator{URL: "https://radio-t.com", SiteID: "radio-t"}, CommentID: "id-1",
+		UserID: "user5", Val: true})
+	assert.NoError(t, err, "user5 +1, score 3")
+	assert.Equal(t, 3, c.Score)
+
+	c, err = b.Vote(VoteReq{Locator: store.Locator{URL: "https://radio-t.com", SiteID: "radio-t"}, CommentID: "id-1",
+		UserID: "user5", Val: false})
+	assert.NoError(t, err, "user5 -1, score reset to 2")
+	assert.Equal(t, 2, c.Score)
+
+	c, err = b.Vote(VoteReq{Locator: store.Locator{URL: "https://radio-t.com", SiteID: "radio-t"}, CommentID: "id-1",
+		UserID: "user5", Val: false})
+	assert.NoError(t, err, "user5 -1, score 1")
+	assert.Equal(t, 1, c.Score)
+
+	// allow negative voting
+	b.PositiveScore = false
 	c, err = b.Vote(VoteReq{Locator: store.Locator{URL: "https://radio-t.com", SiteID: "radio-t"}, CommentID: "id-1",
 		UserID: "user2", Val: false})
 	assert.NoError(t, err, "minimal score ignored")
@@ -504,8 +526,7 @@ func TestService_VoteSameIP(t *testing.T) {
 
 	eng, teardown := prepStoreEngine(t)
 	defer teardown()
-	b := DataStore{Engine: eng, AdminStore: admin.NewStaticKeyStore("secret 123"),
-		MaxVotes: -1}
+	b := DataStore{Engine: eng, AdminStore: admin.NewStaticKeyStore("secret 123"), MaxVotes: -1}
 	b.RestrictSameIPVotes.Enabled = true
 
 	c, err := b.Vote(VoteReq{Locator: store.Locator{URL: "https://radio-t.com", SiteID: "radio-t"}, CommentID: "id-2",
@@ -516,12 +537,17 @@ func TestService_VoteSameIP(t *testing.T) {
 	c, err = b.Vote(VoteReq{Locator: store.Locator{URL: "https://radio-t.com", SiteID: "radio-t"}, CommentID: "id-2",
 		UserID: "user3", UserIP: "123", Val: true})
 	assert.EqualError(t, err, "the same ip cce61be6e0a692420ae0de31dceca179123c3b8a already voted for id-2")
-	assert.Equal(t, 1, c.Score, "still have 1 score")
+	assert.Equal(t, 1, c.Score, "still have 1 score, rejected")
 
 	c, err = b.Vote(VoteReq{Locator: store.Locator{URL: "https://radio-t.com", SiteID: "radio-t"}, CommentID: "id-2",
-		UserID: "user3", UserIP: "123", Val: false})
+		UserID: "user2", UserIP: "123", Val: false})
 	assert.NoError(t, err)
 	assert.Equal(t, 0, c.Score, "reset to 0 score, opposite vote allowed")
+
+	c, err = b.Vote(VoteReq{Locator: store.Locator{URL: "https://radio-t.com", SiteID: "radio-t"}, CommentID: "id-2",
+		UserID: "user2", UserIP: "123", Val: false})
+	assert.NoError(t, err)
+	assert.Equal(t, -1, c.Score, "set to -1 score, correction vote allowed")
 }
 
 func TestService_VoteSameIPWithDuration(t *testing.T) {