Improve test coverage to 90% and fix URL scheme driver bug

postgres.go

@@ -34,7 +34,11 @@ func New(u *url.URL) (waitfor.Resource, error) {
 }
 
 func (s *Postgres) Test(ctx context.Context) error {
-	db, err := sql.Open(s.url.Scheme, strings.TrimPrefix(s.url.String(), Scheme+"://"))
+	// Always use "postgres" as the driver name for sql.Open, regardless of the URL scheme
+	// Remove the scheme and "://" from the URL to get the connection string
+	connStr := strings.TrimPrefix(s.url.String(), s.url.Scheme+"://")
+
+	db, err := sql.Open(Scheme, connStr)
 
 	if err != nil {
 		return err

postgres_test.go

@@ -5,6 +5,8 @@ import (
 	"github.com/go-waitfor/waitfor"
 	"github.com/go-waitfor/waitfor-postgres"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"net/url"
 	"testing"
 	"time"
 )
@@ -19,3 +21,73 @@ func TestUse(t *testing.T) {
 
 	assert.Error(t, err)
 }
+
+func TestNew(t *testing.T) {
+	t.Run("with valid URL", func(t *testing.T) {
+		u, err := url.Parse("postgres://localhost:5432/testdb")
+		require.NoError(t, err)
+
+		resource, err := postgres.New(u)
+		assert.NoError(t, err)
+		assert.NotNil(t, resource)
+	})
+
+	t.Run("with nil URL", func(t *testing.T) {
+		resource, err := postgres.New(nil)
+		assert.Error(t, err)
+		assert.Nil(t, resource)
+		assert.Contains(t, err.Error(), "url")
+		assert.Contains(t, err.Error(), "invalid argument")
+	})
+}
+
+func TestPostgres_Test(t *testing.T) {
+	t.Run("with invalid postgres URL", func(t *testing.T) {
+		u, err := url.Parse("postgres://nonexistent:5432/testdb")
+		require.NoError(t, err)
+
+		resource, err := postgres.New(u)
+		require.NoError(t, err)
+
+		ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
+		defer cancel()
+
+		err = resource.Test(ctx)
+		assert.Error(t, err)
+	})
+
+	t.Run("with URL that causes connection failure", func(t *testing.T) {
+		// Use a valid URL format but with invalid host
+		u, err := url.Parse("postgres://user:password@invalid-host:5432/database")
+		require.NoError(t, err)
+
+		resource, err := postgres.New(u)
+		require.NoError(t, err)
+
+		ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
+		defer cancel()
+
+		err = resource.Test(ctx)
+		assert.Error(t, err)
+	})
+
+	t.Run("with postgresql scheme (alternate scheme bug test)", func(t *testing.T) {
+		// This tests a potential bug where using 'postgresql://' scheme
+		// instead of 'postgres://' could cause sql.Open to fail
+		u, err := url.Parse("postgresql://user:password@localhost:5432/database")
+		require.NoError(t, err)
+
+		resource, err := postgres.New(u)
+		require.NoError(t, err)
+
+		ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
+		defer cancel()
+
+		// This should work (or at least fail with connection error, not driver error)
+		err = resource.Test(ctx)
+		// We expect a connection error, not a driver registration error
+		assert.Error(t, err)
+		// The error should not be about unknown driver
+		assert.NotContains(t, err.Error(), "unknown driver")
+	})
+}