Fixes some unit tests to be able to run them on windows

Some of them are skipped for now (because the feature is not supported
or needs more work), some of them are fixed.

Signed-off-by: Vincent Demeester <vincent@sbr.pm>

cli/command/plugin/create_test.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
+	"runtime"
 	"testing"
 
 	"github.com/docker/cli/internal/test"
@@ -14,7 +15,10 @@ import (
 )
 
 func TestCreateErrors(t *testing.T) {
-
+	noSuchFile := "no such file or directory"
+	if runtime.GOOS == "windows" {
+		noSuchFile = "The system cannot find the file specified."
+	}
 	testCases := []struct {
 		args          []string
 		expectedError string
@@ -29,7 +33,7 @@ func TestCreateErrors(t *testing.T) {
 		},
 		{
 			args:          []string{"plugin-foo", "nonexistent_context_dir"},
-			expectedError: "no such file or directory",
+			expectedError: noSuchFile,
 		},
 	}
 
@@ -61,7 +65,12 @@ func TestCreateErrorOnContextDirWithoutConfig(t *testing.T) {
 	cmd := newCreateCommand(cli)
 	cmd.SetArgs([]string{"plugin-foo", tmpDir.Path()})
 	cmd.SetOutput(ioutil.Discard)
-	assert.ErrorContains(t, cmd.Execute(), "config.json: no such file or directory")
+
+	expectedErr := "config.json: no such file or directory"
+	if runtime.GOOS == "windows" {
+		expectedErr = "config.json: The system cannot find the file specified."
+	}
+	assert.ErrorContains(t, cmd.Execute(), expectedErr)
 }
 
 func TestCreateErrorOnInvalidConfig(t *testing.T) {