Support snapshot pagination (#547)

* Support snapshot pagination

* Update yaml

docs/api_docs/bundle.yaml

@@ -790,6 +790,16 @@ paths:
           type: integer
           format: int64
           minimum: 1
+        - in: query
+          name: limit
+          type: integer
+          format: int64
+          description: the number of snapshots to return
+        - in: query
+          name: offset
+          type: integer
+          format: int64
+          description: return snapshots given the offset, it should usually set together with limit
       responses:
         '200':
           description: returns the flag snapshots
@@ -1063,6 +1073,7 @@ definitions:
         type: integer
         format: int64
         minimum: 1
+        readOnly: true
       updatedBy:
         type: string
       flag:

pkg/handler/crud.go

@@ -170,12 +170,20 @@ func (c *crud) GetFlag(params flag.GetFlagParams) middleware.Responder {
 }
 
 func (c *crud) GetFlagSnapshots(params flag.GetFlagSnapshotsParams) middleware.Responder {
+	tx := getDB()
 	fs := []entity.FlagSnapshot{}
-	err := getDB().
+
+	if params.Limit != nil {
+		tx = tx.Limit(int(*params.Limit))
+	}
+	if params.Offset != nil {
+		tx = tx.Offset(int(*params.Offset))
+	}
+
+	if err := tx.
 		Order("created_at desc").
 		Where(entity.FlagSnapshot{FlagID: util.SafeUint(params.FlagID)}).
-		Find(&fs).Error
-	if err != nil {
+		Find(&fs).Error; err != nil {
 		return flag.NewGetFlagSnapshotsDefault(500).WithPayload(
 			ErrorMessage("cannot find flag snapshots for %v. %s", params.FlagID, err))
 	}

pkg/handler/crud_test.go

@@ -462,6 +462,53 @@ func TestFindFlags(t *testing.T) {
 	})
 }
 
+func TestGetFlagSnapshots(t *testing.T) {
+	var res middleware.Responder
+	db := entity.NewTestDB()
+	c := &crud{}
+	numOfSnapshots := 10
+
+	tmpDB, dbErr := db.DB()
+	if dbErr != nil {
+		t.Errorf("Failed to get database")
+	}
+
+	defer tmpDB.Close()
+	defer gostub.StubFunc(&getDB, db).Reset()
+
+	c.CreateFlag(flag.CreateFlagParams{
+		Body: &models.CreateFlagRequest{
+			Description: util.StringPtr("funny flag"),
+		},
+	})
+
+	for i := 0; i < numOfSnapshots; i++ {
+		entity.SaveFlagSnapshot(db, 1, "[email protected]")
+	}
+
+	t.Run("GetFlagSnapshots - got all the results", func(t *testing.T) {
+		res = c.GetFlagSnapshots(flag.GetFlagSnapshotsParams{})
+		assert.Len(t, res.(*flag.GetFlagSnapshotsOK).Payload, numOfSnapshots+1)
+	})
+
+	t.Run("GetFlagSnapshots (with limit)", func(t *testing.T) {
+		res = c.GetFlagSnapshots(flag.GetFlagSnapshotsParams{
+			Limit: util.Int64Ptr(int64(2)),
+		})
+		assert.Len(t, res.(*flag.GetFlagSnapshotsOK).Payload, 2)
+	})
+
+	t.Run("GetFlagSnapshots (with limit and offset)", func(t *testing.T) {
+		res = c.GetFlagSnapshots(flag.GetFlagSnapshotsParams{
+			Limit:  util.Int64Ptr(int64(2)),
+			Offset: util.Int64Ptr(int64(2)),
+		})
+		assert.Len(t, res.(*flag.GetFlagSnapshotsOK).Payload, 2)
+		assert.Equal(t, int64(9), res.(*flag.GetFlagSnapshotsOK).Payload[0].ID)
+		assert.Equal(t, int64(8), res.(*flag.GetFlagSnapshotsOK).Payload[1].ID)
+	})
+}
+
 func TestCrudSegments(t *testing.T) {
 	var res middleware.Responder
 	db := entity.NewTestDB()

pkg/mapper/entity_restapi/e2r/e2r.go

@@ -56,7 +56,7 @@ func MapFlagSnapshot(e *entity.FlagSnapshot) (*models.FlagSnapshot, error) {
 	}
 	r := &models.FlagSnapshot{
 		Flag:      f,
-		ID:        util.Int64Ptr(int64(e.ID)),
+		ID:        int64(e.ID),
 		UpdatedBy: e.UpdatedBy,
 		UpdatedAt: util.StringPtr(e.UpdatedAt.UTC().Format(time.RFC3339)),
 	}

swagger/flag_snapshots.yaml

@@ -10,6 +10,16 @@ get:
       type: integer
       format: int64
       minimum: 1
+    - in: query
+      name: limit
+      type: integer
+      format: int64
+      description: the number of snapshots to return
+    - in: query
+      name: offset
+      type: integer
+      format: int64
+      description: return snapshots given the offset, it should usually set together with limit
   responses:
     200:
       description: returns the flag snapshots

swagger/index.yaml

@@ -203,6 +203,7 @@ definitions:
         type: integer
         format: int64
         minimum: 1
+        readOnly: true
       updatedBy:
         type: string
       flag: