Expose public/ API as submodule (#23345)

* model -> public/model

* plugin -> public/plugin

* public/model/utils -> public/utils

* platform/shared/mlog -> public/shared/mlog

* platform/shared/i18n -> public/shared/i18n

* platform/shared/markdown -> public/shared/markdown

* platform/services/timezones -> public/shared/timezones

* channels/einterfaces -> einterfaces

* expose public/ submodule

* go mod tidy

* .github: cache-dependency-path, setup-go-work

* modules-tidy for public/ too

* remove old gomodtidy

server/public/utils/file_test.go

@@ -0,0 +1,63 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package utils
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCopyDir(t *testing.T) {
+	srcDir, err := os.MkdirTemp("", "src")
+	require.NoError(t, err)
+	defer os.RemoveAll(srcDir)
+
+	dstParentDir, err := os.MkdirTemp("", "dstparent")
+	require.NoError(t, err)
+	defer os.RemoveAll(dstParentDir)
+
+	dstDir := filepath.Join(dstParentDir, "dst")
+
+	tempFile := "temp.txt"
+	err = os.WriteFile(filepath.Join(srcDir, tempFile), []byte("test file"), 0655)
+	require.NoError(t, err)
+
+	childDir := "child"
+	err = os.Mkdir(filepath.Join(srcDir, childDir), 0777)
+	require.NoError(t, err)
+
+	childTempFile := "childtemp.txt"
+	err = os.WriteFile(filepath.Join(srcDir, childDir, childTempFile), []byte("test file"), 0755)
+	require.NoError(t, err)
+
+	err = CopyDir(srcDir, dstDir)
+	assert.NoError(t, err)
+
+	stat, err := os.Stat(filepath.Join(dstDir, tempFile))
+	assert.NoError(t, err)
+	assert.Equal(t, uint32(0655), uint32(stat.Mode()))
+	assert.False(t, stat.IsDir())
+	data, err := os.ReadFile(filepath.Join(dstDir, tempFile))
+	assert.NoError(t, err)
+	assert.Equal(t, "test file", string(data))
+
+	stat, err = os.Stat(filepath.Join(dstDir, childDir))
+	assert.NoError(t, err)
+	assert.True(t, stat.IsDir())
+
+	stat, err = os.Stat(filepath.Join(dstDir, childDir, childTempFile))
+	assert.NoError(t, err)
+	assert.Equal(t, uint32(0755), uint32(stat.Mode()))
+	assert.False(t, stat.IsDir())
+	data, err = os.ReadFile(filepath.Join(dstDir, childDir, childTempFile))
+	assert.NoError(t, err)
+	assert.Equal(t, "test file", string(data))
+
+	err = CopyDir(srcDir, dstDir)
+	assert.Error(t, err)
+}