task: adding connection params

db/connection.go

@@ -2,15 +2,20 @@ package db
 
 import (
 	"database/sql"
+	"net/url"
+	"strings"
 	"sync"
 )
 
 var (
 	dbPool = map[string]*sql.DB{}
 	cmux   sync.Mutex
 
-	//DriverName defaults to postgres
+	// DriverName defaults to postgres
 	driverName = "postgres"
+
+	// Connection params to be appended to the connection string
+	connParams string
 )
 
 // ConnFn is the database connection builder function that
@@ -39,11 +44,22 @@ func ConnectionFn(url string, opts ...connectionOption) ConnFn {
 			v()
 		}
 
-		conn, err := sql.Open(driverName, url)
+		// Modify the URL to include connection params
+		// if any.
+		modURL := url
+		if strings.Contains(modURL, "?") {
+			modURL = modURL + "&" + connParams
+		} else if connParams != "" {
+			modURL = modURL + "?" + connParams
+		}
+
+		conn, err := sql.Open(driverName, modURL)
 		if err != nil {
 			return nil, err
 		}
 
+		// This uses url instead of modURL while the params apply
+		// to all connections.
 		dbPool[url] = conn
 
 		return conn, nil
@@ -57,3 +73,24 @@ func WithDriver(name string) connectionOption {
 		driverName = name
 	}
 }
+
+// Params allows to specify additional connection parameters
+// that will be encoded as URL params next to the connection string.
+// params should be in key,value,key,value,... format.
+// e.g Params("sslmode", "disable", "timezone", "UTC")
+func Params(params ...string) connectionOption {
+	vals := url.Values{}
+	for i := 0; i < len(params); i += 2 {
+		key := params[i]
+		if i+1 >= len(params) {
+			vals.Add(key, "")
+			break
+		}
+
+		vals.Add(key, params[i+1])
+	}
+
+	return func() {
+		connParams = vals.Encode()
+	}
+}

db/connection_test.go

@@ -11,26 +11,26 @@ func TestConnection(t *testing.T) {
 	urls := []string{"test_1.db", "test_2.db", "test_3.db"}
 
 	createDatabases := func() {
-		for _, dbUrl := range urls {
-			if err := db.Create(dbUrl); err != nil {
+		for _, url := range urls {
+			if err := db.Create(url); err != nil {
 				t.Errorf("error creating db: %v", err)
 			}
 		}
-
 	}
+
 	t.Run("Correct - creating multiple connections", func(t *testing.T) {
 		t.Cleanup(func() {
-			for _, dbUrl := range urls {
-				if err := db.Drop(dbUrl); err != nil {
+			for _, url := range urls {
+				if err := db.Drop(url); err != nil {
 					t.Errorf("error dropping db: %v", err)
 				}
 			}
 		})
 
 		createDatabases()
 
-		for _, dbUrl := range urls {
-			conFn := db.ConnectionFn(dbUrl, db.WithDriver("sqlite3"))
+		for _, url := range urls {
+			conFn := db.ConnectionFn(url, db.WithDriver("sqlite3"))
 
 			conn, err := conFn()
 			if err != nil {
@@ -42,10 +42,11 @@ func TestConnection(t *testing.T) {
 			}
 		}
 	})
+
 	t.Run("Correct - using current exiting connection if already created", func(t *testing.T) {
 		t.Cleanup(func() {
-			for _, dbUrl := range urls {
-				if err := db.Drop(dbUrl); err != nil {
+			for _, url := range urls {
+				if err := db.Drop(url); err != nil {
 					t.Errorf("error dropping db: %v", err)
 				}
 			}
@@ -55,15 +56,15 @@ func TestConnection(t *testing.T) {
 
 		var currentConn *sql.DB
 
-		for _, dbUrl := range urls {
-			conFn := db.ConnectionFn(dbUrl, db.WithDriver("sqlite3"))
+		for _, url := range urls {
+			conFn := db.ConnectionFn(url, db.WithDriver("sqlite3"))
 
 			conn, err := conFn()
 			if err != nil {
 				t.Errorf("Expected nil, got err %v", err)
 			}
 
-			if dbUrl == urls[0] {
+			if url == urls[0] {
 				currentConn = conn
 			}
 
@@ -83,4 +84,47 @@ func TestConnection(t *testing.T) {
 			t.Errorf("Expected current connection to be %v, got %v", currentConn, conn)
 		}
 	})
+
+	t.Run("connection params", func(t *testing.T) {
+		cases := []string{
+			":memory:",
+			"file::memory:?cache=shared",
+			t.TempDir() + "memory.db",
+			t.TempDir() + "memory.db?mode=memory",
+		}
+
+		for _, tcase := range cases {
+			t.Run(tcase, func(t *testing.T) {
+				connFn := db.ConnectionFn(
+					tcase,
+
+					db.WithDriver("sqlite3"),
+					db.Params("_cache_size", "54321"), // Applying cache size parameter to check it later.
+				)
+
+				conn, err := connFn()
+				if err != nil {
+					t.Errorf("Expected nil, got err %v", err)
+				}
+				defer conn.Close()
+
+				rows, err := conn.Query("pragma cache_size;")
+				if err != nil {
+					t.Errorf("Expected nil, got err %v", err)
+				}
+				defer rows.Close()
+
+				var size int
+				for rows.Next() {
+					if err := rows.Scan(&size); err != nil {
+						t.Errorf("Expected nil, got err %v", err)
+					}
+				}
+
+				if size != 54321 {
+					t.Fatalf("Expected cache size to be 54321, got %v", size)
+				}
+			})
+		}
+	})
 }