1 files changed, 64 insertions, 0 deletions
diff --git a/lib/btrfs/btrfstree/btree_err_test.go b/lib/btrfs/btrfstree/btree_err_test.go
new file mode 100644
index 0000000..381bd56
--- /dev/null
+++ b/lib/btrfs/btrfstree/btree_err_test.go
@@ -0,0 +1,64 @@
+// Copyright (C) 2023  Luke Shumaker <lukeshu@lukeshu.com>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+package btrfstree_test
+
+import (
+	"errors"
+	"fmt"
+	iofs "io/fs"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfstree"
+)
+
+func TestErrs(t *testing.T) {
+	t.Parallel()
+
+	errItem := fmt.Errorf("my item: %w", btrfstree.ErrNoItem)
+	errTree := fmt.Errorf("my tree: %w", btrfstree.ErrNoTree)
+
+	// 1. errItem
+	// 2. errTree
+	// 3. btrfstree.ErrNoItem
+	// 4. btrfstree.ErrNoTree
+	// 5. iofs.ErrNotExist
+
+	// 1
+	assert.Equal(t, errors.Is(errItem, errItem), true)
+	assert.Equal(t, errors.Is(errItem, errTree), false)
+	assert.Equal(t, errors.Is(errItem, btrfstree.ErrNoItem), true)
+	assert.Equal(t, errors.Is(errItem, btrfstree.ErrNoTree), false)
+	assert.Equal(t, errors.Is(errItem, iofs.ErrNotExist), true)
+
+	// 2
+	assert.Equal(t, errors.Is(errTree, errItem), false)
+	assert.Equal(t, errors.Is(errTree, errTree), true)
+	assert.Equal(t, errors.Is(errTree, btrfstree.ErrNoItem), false)
+	assert.Equal(t, errors.Is(errTree, btrfstree.ErrNoTree), true)
+	assert.Equal(t, errors.Is(errTree, iofs.ErrNotExist), true)
+
+	// 3
+	assert.Equal(t, errors.Is(btrfstree.ErrNoItem, errItem), false)
+	assert.Equal(t, errors.Is(btrfstree.ErrNoItem, errTree), false)
+	assert.Equal(t, errors.Is(btrfstree.ErrNoItem, btrfstree.ErrNoItem), true)
+	assert.Equal(t, errors.Is(btrfstree.ErrNoItem, btrfstree.ErrNoTree), false)
+	assert.Equal(t, errors.Is(btrfstree.ErrNoItem, iofs.ErrNotExist), true)
+
+	// 4
+	assert.Equal(t, errors.Is(btrfstree.ErrNoTree, errItem), false)
+	assert.Equal(t, errors.Is(btrfstree.ErrNoTree, errTree), false)
+	assert.Equal(t, errors.Is(btrfstree.ErrNoTree, btrfstree.ErrNoItem), false)
+	assert.Equal(t, errors.Is(btrfstree.ErrNoTree, btrfstree.ErrNoTree), true)
+	assert.Equal(t, errors.Is(btrfstree.ErrNoTree, iofs.ErrNotExist), true)
+
+	// 5
+	assert.Equal(t, errors.Is(iofs.ErrNotExist, errItem), false)
+	assert.Equal(t, errors.Is(iofs.ErrNotExist, errTree), false)
+	assert.Equal(t, errors.Is(iofs.ErrNotExist, btrfstree.ErrNoItem), false)
+	assert.Equal(t, errors.Is(iofs.ErrNotExist, btrfstree.ErrNoTree), false)
+	assert.Equal(t, errors.Is(iofs.ErrNotExist, iofs.ErrNotExist), true)
+}