Add missing test cases

Now all combinations of keeping/changing filenames and file contents are
covered.

Author: tchap

pkg/operator/staticpod/certsyncpod/certsync_controller_test.go

@@ -127,7 +127,7 @@ func TestWriteFiles(t *testing.T) {
 			checkState: checkOnSuccess,
 		},
 		{
-			name:  "update target directory change file content",
+			name:  "change file contents preserving the filenames",
 			newFS: newRealFS,
 			directoryData: map[string][]byte{
 				"tls.crt": []byte("TLS cert"),
@@ -140,7 +140,20 @@ func TestWriteFiles(t *testing.T) {
 			checkState: checkOnSuccess,
 		},
 		{
-			name:  "update target directory change filenames",
+			name:  "change filenames preserving the file contents",
+			newFS: newRealFS,
+			directoryData: map[string][]byte{
+				"tls.crt": []byte("TLS cert"),
+				"tls.key": []byte("TLS key"),
+			},
+			objectData: map[string][]byte{
+				"api.crt": []byte("TLS cert"),
+				"api.key": []byte("TLS key"),
+			},
+			checkState: checkOnSuccess,
+		},
+		{
+			name:  "change filenames and file contents",
 			newFS: newRealFS,
 			directoryData: map[string][]byte{
 				"tls.crt": []byte("TLS cert"),
@@ -152,6 +165,45 @@ func TestWriteFiles(t *testing.T) {
 			},
 			checkState: checkOnSuccess,
 		},
+		{
+			name:  "replace a single file content",
+			newFS: newRealFS,
+			directoryData: map[string][]byte{
+				"1.txt": []byte("1"),
+				"2.txt": []byte("2"),
+			},
+			objectData: map[string][]byte{
+				"1.txt": []byte("1"),
+				"2.txt": []byte("3"),
+			},
+			checkState: checkOnSuccess,
+		},
+		{
+			name:  "replace a single file",
+			newFS: newRealFS,
+			directoryData: map[string][]byte{
+				"1.txt": []byte("1"),
+				"2.txt": []byte("2"),
+			},
+			objectData: map[string][]byte{
+				"1.txt": []byte("1"),
+				"3.txt": []byte("3"),
+			},
+			checkState: checkOnSuccess,
+		},
+		{
+			name:  "rename a single file",
+			newFS: newRealFS,
+			directoryData: map[string][]byte{
+				"1.txt": []byte("1"),
+				"2.txt": []byte("2"),
+			},
+			objectData: map[string][]byte{
+				"1.txt": []byte("1"),
+				"3.txt": []byte("2"),
+			},
+			checkState: checkOnSuccess,
+		},
 		errorTestCase("directory unchanged on failed to create object directory", func() *fileSystem {
 			fs := newRealFS()
 			fs.MkdirAll = func(path string, perm os.FileMode) error {