Add MustCheckExists to filez.

filez/filez.go

@@ -90,3 +90,15 @@ func WithMustCreateTempDir(pattern string, f func(dirPath string)) {
 
 	f(dirPath)
 }
+
+// MustCheckExists checks if the given path exists, panics on error (other than os.ErrNotExist).
+func MustCheckExists(fileOrDirPath string) bool {
+	_, err := os.Stat(fileOrDirPath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return false
+		}
+		panic(err)
+	}
+	return true
+}

filez/filez_test.go

@@ -63,3 +63,21 @@ func TestFilesAndDirectories(t *testing.T) {
 	require.Error(t, err)
 	require.True(t, os.IsNotExist(err))
 }
+
+func TestMustCheckExists(t *testing.T) {
+	filez.WithMustCreateTempDir("golang-bites", func(dirPath string) {
+		require.True(t, filez.MustCheckExists(dirPath))
+	})
+
+	var deletedFilePath string
+	filez.WithMustWriteTempFile("golang-bites", []byte("temp"), func(filePath string) {
+		require.True(t, filez.MustCheckExists(filePath))
+		deletedFilePath = filePath
+	})
+
+	require.False(t, filez.MustCheckExists(deletedFilePath))
+
+	require.Panics(t, func() {
+		filez.MustCheckExists(string([]byte{0}))
+	})
+}