Pull request #1558: add-dnssvc

Merge in DNS/adguard-home from add-dnssvc to master

Squashed commit of the following:

commit 55f4f114bab65a03c0d65383e89020a7356cff32
Merge: 95dc28d9 6e63757f
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Mon Aug 15 20:53:07 2022 +0300

    Merge branch 'master' into add-dnssvc

commit 95dc28d9d77d06e8ac98c1e6772557bffbf1705b
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Mon Aug 15 20:52:50 2022 +0300

    all: imp tests, docs

commit 0d9d02950d84afd160b4b1c118da856cee6f12e5
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Aug 11 19:27:59 2022 +0300

    all: imp docs

commit 8990e038a81da4430468da12fcebedf79fe14df6
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Aug 11 19:05:29 2022 +0300

    all: imp tests more

commit 92730d93a2a1ac77888c2655508e43efaf0e9fde
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Aug 11 18:37:48 2022 +0300

    all: imp tests more

commit 8cd45ba30da7ac310e9dc666fb2af438e577b02d
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Aug 11 18:11:15 2022 +0300

    all: add v1 dnssvc stub; refactor tests

internal/aghos/filewalker_internal_test.go

@@ -0,0 +1,57 @@
+package aghos
+
+import (
+	"io/fs"
+	"path"
+	"testing"
+	"testing/fstest"
+
+	"github.com/AdguardTeam/golibs/errors"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// errFS is an fs.FS implementation, method Open of which always returns
+// errFSOpen.
+type errFS struct{}
+
+// errFSOpen is returned from errGlobFS.Open.
+const errFSOpen errors.Error = "test open error"
+
+// Open implements the fs.FS interface for *errGlobFS.  fsys is always nil and
+// err is always errFSOpen.
+func (efs *errFS) Open(name string) (fsys fs.File, err error) {
+	return nil, errFSOpen
+}
+
+func TestWalkerFunc_CheckFile(t *testing.T) {
+	emptyFS := fstest.MapFS{}
+
+	t.Run("non-existing", func(t *testing.T) {
+		_, ok, err := checkFile(emptyFS, nil, "lol")
+		require.NoError(t, err)
+
+		assert.True(t, ok)
+	})
+
+	t.Run("invalid_argument", func(t *testing.T) {
+		_, ok, err := checkFile(&errFS{}, nil, "")
+		require.ErrorIs(t, err, errFSOpen)
+
+		assert.False(t, ok)
+	})
+
+	t.Run("ignore_dirs", func(t *testing.T) {
+		const dirName = "dir"
+
+		testFS := fstest.MapFS{
+			path.Join(dirName, "file"): &fstest.MapFile{Data: []byte{}},
+		}
+
+		patterns, ok, err := checkFile(testFS, nil, dirName)
+		require.NoError(t, err)
+
+		assert.Empty(t, patterns)
+		assert.True(t, ok)
+	})
+}