chore: add travis ci config and update readme

Author: x22n

.travis.yml

@@ -0,0 +1,14 @@
+language: go
+
+go:
+  - 1.12.x
+  - tip
+
+before_install:
+  - go get -t -v ./...
+
+script:
+  - go test -race -coverprofile=coverage.txt -covermode=atomic
+
+after_success:
+  - bash <(curl -s https://codecov.io/bash)

README.md

@@ -1,3 +1,8 @@
-#Kendo data query
-Does not support multiple sort
-Only supports `and` filter conditions
+# Kendo data query for Go
+
+[![GoDoc](https://godoc.org/github.com/XavierTS/kendo-data-query?status.svg)](https://godoc.org/github.com/XavierTS/kendo-data-query)
+
+## Limitations
+
+* Does not support multiple sortss
+* Only supports `and` filter conditions

apply.go

@@ -102,9 +102,8 @@ func (d *DataState) getTotal(collection mgo.Collection) (total int, err error) {
 			})
 		}
 
-		//test
-		data := []interface{}{}
-		collection.Pipe(pipeline).All(&data)
+		data := []interface{}{} // TODO wrong data type
+		err = collection.Pipe(pipeline).All(&data)
 	} else {
 		total, err = collection.Find(filter).Count()
 	}
@@ -152,8 +151,6 @@ func (d *DataState) getAggregate() (aggregate []bson.M) {
 		ids[key] = fmt.Sprintf("$_id.%s", key)
 	}
 
-	aggregate = append(aggregate, d.getFirstGrouping())
-
 	nbGroups := len(d.Group) - 1
 	for i := nbGroups; i >= 0; i-- {
 		group := d.Group[i]
@@ -214,12 +211,11 @@ func (d *DataState) addAggregates(m bson.M, firstlevel bool) bson.M {
 	aggregates := bson.M{}
 
 	for _, a := range d.Aggregates {
-		aggregateKey := fmt.Sprintf("$%s", d.toMongoAggregate(a.Aggregate))
+		key := a.getKey()
 		aggregate := bson.M{
-			aggregateKey: getAggregateExpression(a, firstlevel),
+			fmt.Sprintf("$%s", d.toMongoAggregate(a.Aggregate)): getAggregateExpression(a, firstlevel),
 		}
 
-		key := a.getKey()
 		if agg, ok := aggregates[key]; ok {
 			m, _ := agg.(bson.M)
 			m[a.Aggregate] = aggregate