chore: update View method signature in tests

Author: aymanbagabas

exec_test.go

@@ -2,6 +2,7 @@ package tea
 
 import (
 	"bytes"
+	"fmt"
 	"os/exec"
 	"runtime"
 	"testing"
@@ -34,7 +35,7 @@ func (m *testExecModel) Update(msg Msg) (*testExecModel, Cmd) {
 	return m, nil
 }
 
-func (m *testExecModel) View() Frame {
+func (m *testExecModel) View() fmt.Stringer {
 	return NewFrame("\n")
 }
 

tea_test.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"errors"
+	"fmt"
 	"io"
 	"sync/atomic"
 	"testing"
@@ -50,7 +51,7 @@ func (m *testModel) Update(msg Msg) (*testModel, Cmd) {
 	return m, nil
 }
 
-func (m *testModel) View() Frame {
+func (m *testModel) View() fmt.Stringer {
 	m.executed.Store(true)
 	return NewFrame("success\n")
 }