fix: implement InstanceDisposer to close db connections (#136)

* fix: implement InstanceDisposer to close db connections
* fix: adapt Dispose() test to new functionality

Author: njvrzm

connector.go

@@ -134,6 +134,15 @@ func (ds *Connector) storeDBConnection(key string, dbConn dbConnection) {
 	ds.connections.Store(key, dbConn)
 }
 
+// Dispose is called when an existing SQLDatasource needs to be replaced
+func (c *Connector) Dispose() {
+	c.connections.Range(func(_, conn interface{}) bool {
+		_ = conn.(dbConnection).db.Close()
+		return true
+	})
+	c.connections.Clear()
+}
+
 func (c *Connector) GetConnectionFromQuery(ctx context.Context, q *Query) (string, dbConnection, error) {
 	if !c.enableMultipleConnections && !c.driverSettings.ForwardHeaders && len(q.ConnectionArgs) > 0 {
 		return "", dbConnection{}, MissingMultipleConnectionsConfig

datasource.go

@@ -82,6 +82,7 @@ func NewDatasource(c Driver) *SQLDatasource {
 // Dispose cleans up datasource instance resources.
 // Note: Called when testing and saving a datasource
 func (ds *SQLDatasource) Dispose() {
+	ds.connector.Dispose()
 }
 
 // QueryData creates the Responses list and executes each query

datasource_connect_test.go

@@ -3,6 +3,7 @@ package sqlds
 import (
 	"context"
 	"database/sql"
+	"database/sql/driver"
 	"encoding/json"
 	"errors"
 	"testing"
@@ -29,6 +30,16 @@ func (d fakeDriver) Converters() []sqlutil.Converter {
 	return []sqlutil.Converter{}
 }
 
+type fakeSQLConnector struct{}
+
+func (f fakeSQLConnector) Connect(_ context.Context) (driver.Conn, error) {
+	return nil, nil
+}
+
+func (f fakeSQLConnector) Driver() driver.Driver {
+	return nil
+}
+
 func Test_getDBConnectionFromQuery(t *testing.T) {
 	db := &sql.DB{}
 	db2 := &sql.DB{}
@@ -108,20 +119,21 @@ func Test_getDBConnectionFromQuery(t *testing.T) {
 }
 
 func Test_Dispose(t *testing.T) {
-	t.Run("it should not delete connections", func(t *testing.T) {
-		conn := &Connector{}
-
+	t.Run("it should close connections", func(t *testing.T) {
+		db := sql.OpenDB(fakeSQLConnector{})
+		d := &fakeDriver{openDBfn: func(msg json.RawMessage) (*sql.DB, error) { return db, nil }}
+		conn := &Connector{driver: d}
 		ds := &SQLDatasource{connector: conn}
-		conn.connections.Store(defaultKey("uid1"), dbConnection{})
-		conn.connections.Store("foo", dbConnection{})
+		conn.connections.Store(defaultKey("uid1"), dbConnection{db: db})
+		conn.connections.Store("foo", dbConnection{db: db})
 		ds.Dispose()
 		count := 0
 		conn.connections.Range(func(key, value interface{}) bool {
 			count++
 			return true
 		})
-		if count != 2 {
-			t.Errorf("missing connections")
+		if count != 0 {
+			t.Errorf("did not close all connections")
 		}
 	})
 }