kubeadm: increase ut coverage for util/dryrun

Signed-off-by: xin.li <xin.li@daocloud.io>

cmd/kubeadm/app/util/dryrun/dryrun_test.go

@@ -0,0 +1,127 @@
+/*
+Copyright 2024 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package dryrun
+
+import (
+	"bytes"
+	"os"
+	"path/filepath"
+	"reflect"
+	"testing"
+)
+
+func TestPrintDryRunFiles(t *testing.T) {
+	tmpdir, err := os.MkdirTemp("", "")
+	if err != nil {
+		t.Fatalf("Couldn't create tmpdir: %v", err)
+	}
+	defer func() {
+		if err = os.RemoveAll(tmpdir); err != nil {
+			t.Fatalf("Couldn't remove tmpdir: %v", err)
+		}
+	}()
+	fileContents := "apiVersion: kubeadm.k8s.io/unknownVersion"
+	filename := "testfile"
+	cfgPath := filepath.Join(tmpdir, filename)
+	err = os.WriteFile(cfgPath, []byte(fileContents), 0644)
+	if err != nil {
+		t.Fatalf("Couldn't write context to file: %v", err)
+	}
+
+	tests := []struct {
+		name    string
+		files   []FileToPrint
+		wantW   string
+		wantErr bool
+	}{
+		{
+			name: "RealPath is empty",
+			files: []FileToPrint{
+				{
+					RealPath:  "",
+					PrintPath: cfgPath,
+				},
+			},
+			wantW:   "",
+			wantErr: false,
+		},
+		{
+			name: "RealPath is a file that does not exist",
+			files: []FileToPrint{
+				{
+					RealPath:  tmpdir + "/missingfile",
+					PrintPath: cfgPath,
+				},
+			},
+			wantW:   "",
+			wantErr: true,
+		},
+		{
+			name: "RealPath is a readable file",
+			files: []FileToPrint{
+				{
+					RealPath:  cfgPath,
+					PrintPath: "",
+				},
+			},
+			wantW: "[dryrun] Would write file \"" + cfgPath + "\" with content:\n" +
+				"	apiVersion: kubeadm.k8s.io/unknownVersion\n",
+			wantErr: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			w := &bytes.Buffer{}
+			if err := PrintDryRunFiles(tt.files, w); (err != nil) != tt.wantErr {
+				t.Errorf("error: %v, expected error: %v", err, tt.wantErr)
+				return
+			}
+			if gotW := w.String(); gotW != tt.wantW {
+				t.Errorf("output: %v, expected output: %v", gotW, tt.wantW)
+			}
+		})
+	}
+}
+
+func TestNewFileToPrint(t *testing.T) {
+	tests := []struct {
+		realPath  string
+		printPath string
+		want      FileToPrint
+	}{
+		{
+			realPath:  "",
+			printPath: "",
+			want:      FileToPrint{},
+		},
+		{
+			realPath:  "/etc/kubernetes",
+			printPath: "/tmp/kubernetes",
+			want: FileToPrint{
+				"/etc/kubernetes",
+				"/tmp/kubernetes",
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run("TestNewFileToPrint", func(t *testing.T) {
+			if got := NewFileToPrint(tt.realPath, tt.printPath); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("got: %v, want: %v", got, tt.want)
+			}
+		})
+	}
+}