preserve order in group by filter

go.mod

@@ -11,7 +11,9 @@ require (
 )
 
 require (
+	github.com/elliotchance/orderedmap/v2 v2.2.0 // indirect
 	github.com/osteele/tuesday v1.0.3 // indirect
+	github.com/umpc/go-sortedmap v0.0.0-20180422175548-64ab94c482f4 // indirect
 	golang.org/x/net v0.0.0-20201224014010-6772e930b67b // indirect
 	golang.org/x/sys v0.4.0 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect

go.sum

@@ -1,5 +1,7 @@
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/elliotchance/orderedmap/v2 v2.2.0 h1:7/2iwO98kYT4XkOjA9mBEIwvi4KpGB4cyHeOFOnj4Vk=
+github.com/elliotchance/orderedmap/v2 v2.2.0/go.mod h1:85lZyVbpGaGvHvnKa7Qhx7zncAdBIBq6u56Hb1PRU5Q=
 github.com/fsnotify/fsnotify v1.7.0 h1:8JEhPFa5W2WU7YfeZzPNqzMP6Lwt7L2715Ggo0nosvA=
 github.com/fsnotify/fsnotify v1.7.0/go.mod h1:40Bi/Hjc2AVfZrqy+aj+yEI+/bRxZnMJyTJwOpGvigM=
 github.com/niklasfasching/go-org v1.7.0 h1:vyMdcMWWTe/XmANk19F4k8XGBYg0GQ/gJGMimOjGMek=
@@ -12,6 +14,9 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.7.1 h1:5TQK59W5E3v0r2duFAb7P95B6hEeOyEnHRa8MjYSMTY=
+github.com/umpc/go-sortedmap v0.0.0-20180422175548-64ab94c482f4 h1:qk1XyC6UGfPa51PGmsTQJavyhfMLScqw97pEV3sFClI=
+github.com/umpc/go-sortedmap v0.0.0-20180422175548-64ab94c482f4/go.mod h1:X6iKjXCleSyo/LZzKZ9zDF/ZB2L9gC36I5gLMf32w3M=
 github.com/yuin/goldmark v1.7.0 h1:EfOIvIMZIzHdB/R/zVrikYLPPwJlfMcNczJFMs1m6sA=
 github.com/yuin/goldmark v1.7.0/go.mod h1:uzxRWxtg69N339t3louHJ7+O03ezfj6PlliRlaOzY1E=
 golang.org/x/net v0.0.0-20201224014010-6772e930b67b h1:iFwSg7t5GZmB/Q5TjiEAsdoLDrdJRC1RiF2WhuV29Qw=

templates/filters.go

@@ -8,6 +8,7 @@ import (
 	"encoding/xml"
 	"time"
 
+	"github.com/elliotchance/orderedmap/v2"
 	"github.com/osteele/liquid"
 	"github.com/osteele/liquid/evaluator"
 	"github.com/osteele/liquid/expressions"
@@ -75,48 +76,51 @@ func groupByExpFilter(array []map[string]interface{}, name string, expr expressi
 	if !(rt.Kind() != reflect.Array || rt.Kind() == reflect.Slice) {
 		return nil, nil
 	}
-	groups := map[interface{}][]interface{}{}
+	groups := orderedmap.NewOrderedMap[interface{}, []interface{}]()
 	for i := 0; i < rt.Len(); i++ {
 		item := rt.Index(i).Interface()
 		key, err := expr.Bind(name, item).Evaluate()
 		if err != nil {
 			return nil, err
 		}
-		if group, found := groups[key]; found {
+		if group, found := groups.Get(key); found {
-			groups[key] = append(group, item)
+			groups.Set(key, append(group, item))
 		} else {
-			groups[key] = []interface{}{item}
+			groups.Set(key, []interface{}{item})
 		}
 	}
 	var result []map[string]interface{}
-	for k, v := range groups {
+	for _, k := range groups.Keys() {
+		v, _ := groups.Get(k)
 		result = append(result, map[string]interface{}{"name": k, "items": v})
 	}
 	return result, nil
 }
 
+// TODO use ordered map
 func groupByFilter(array []map[string]interface{}, property string) []map[string]interface{} {
 	rt := reflect.ValueOf(array)
 	if !(rt.Kind() != reflect.Array || rt.Kind() == reflect.Slice) {
 		return nil
 	}
-	groups := map[interface{}][]interface{}{}
+	groups := orderedmap.NewOrderedMap[interface{}, []interface{}]()
 	for i := 0; i < rt.Len(); i++ {
 		irt := rt.Index(i)
 		if irt.Kind() == reflect.Map && irt.Type().Key().Kind() == reflect.String {
 			krt := irt.MapIndex(reflect.ValueOf(property))
 			if krt.IsValid() && krt.CanInterface() {
 				key := krt.Interface()
-				if group, found := groups[key]; found {
+				if group, found := groups.Get(key); found {
-					groups[key] = append(group, irt.Interface())
+					groups.Set(key, append(group, irt.Interface()))
 				} else {
-					groups[key] = []interface{}{irt.Interface()}
+					groups.Set(key, []interface{}{irt.Interface()})
 				}
 			}
 		}
 	}
 	var result []map[string]interface{}
-	for k, v := range groups {
+	for _, k := range groups.Keys() {
+		v, _ := groups.Get(k)
 		result = append(result, map[string]interface{}{"name": k, "items": v})
 	}
 	return result