Add Known Folders support on Windows

base_dirs.go

@@ -1,5 +1,7 @@
 package xdg
 
+import "github.com/adrg/xdg/internal/pathutil"
+
 // XDG Base Directory environment variables.
 const (
 	envDataHome   = "XDG_DATA_HOME"
@@ -26,41 +28,41 @@ type baseDirectories struct {
 }
 
 func (bd baseDirectories) dataFile(relPath string) (string, error) {
-	return createPath(relPath, append([]string{bd.dataHome}, bd.data...))
+	return pathutil.Create(relPath, append([]string{bd.dataHome}, bd.data...))
 }
 
 func (bd baseDirectories) configFile(relPath string) (string, error) {
-	return createPath(relPath, append([]string{bd.configHome}, bd.config...))
+	return pathutil.Create(relPath, append([]string{bd.configHome}, bd.config...))
 }
 
 func (bd baseDirectories) stateFile(relPath string) (string, error) {
-	return createPath(relPath, []string{bd.stateHome})
+	return pathutil.Create(relPath, []string{bd.stateHome})
 }
 
 func (bd baseDirectories) cacheFile(relPath string) (string, error) {
-	return createPath(relPath, []string{bd.cacheHome})
+	return pathutil.Create(relPath, []string{bd.cacheHome})
 }
 
 func (bd baseDirectories) runtimeFile(relPath string) (string, error) {
-	return createPath(relPath, []string{bd.runtime})
+	return pathutil.Create(relPath, []string{bd.runtime})
 }
 
 func (bd baseDirectories) searchDataFile(relPath string) (string, error) {
-	return searchFile(relPath, append([]string{bd.dataHome}, bd.data...))
+	return pathutil.Search(relPath, append([]string{bd.dataHome}, bd.data...))
 }
 
 func (bd baseDirectories) searchConfigFile(relPath string) (string, error) {
-	return searchFile(relPath, append([]string{bd.configHome}, bd.config...))
+	return pathutil.Search(relPath, append([]string{bd.configHome}, bd.config...))
 }
 
 func (bd baseDirectories) searchStateFile(relPath string) (string, error) {
-	return searchFile(relPath, []string{bd.stateHome})
+	return pathutil.Search(relPath, []string{bd.stateHome})
 }
 
 func (bd baseDirectories) searchCacheFile(relPath string) (string, error) {
-	return searchFile(relPath, []string{bd.cacheHome})
+	return pathutil.Search(relPath, []string{bd.cacheHome})
 }
 
 func (bd baseDirectories) searchRuntimeFile(relPath string) (string, error) {
-	return searchFile(relPath, []string{bd.runtime})
+	return pathutil.Search(relPath, []string{bd.runtime})
 }

go.mod

@@ -2,4 +2,7 @@ module github.com/adrg/xdg
 
 go 1.14
 
-require github.com/stretchr/testify v1.7.0
+require (
+	github.com/stretchr/testify v1.7.0
+	golang.org/x/sys v0.0.0-20211020174200-9d6173849985
+)

go.sum

@@ -2,10 +2,11 @@ github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/stretchr/objx v0.1.0 h1:4G4v2dO3VZwixGIRoQ5Lfboy6nUhCyYzaqnIAPPhYs4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+golang.org/x/sys v0.0.0-20211020174200-9d6173849985 h1:LOlKVhfDyahgmqa97awczplwkjzNaELFg3zRIJ13RYo=
+golang.org/x/sys v0.0.0-20211020174200-9d6173849985/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=

internal/pathutil/pathutil.go

@@ -0,0 +1,78 @@
+package pathutil
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// Unique eliminates the duplicate paths from the provided slice and returns
+// the result. The items in the output slice are in the order in which they
+// occur in the input slice. If a `home` location is provided, the paths are
+// expanded using the `ExpandHome` function.
+func Unique(paths []string, home string) []string {
+	var (
+		uniq     []string
+		registry = map[string]struct{}{}
+	)
+
+	for _, p := range paths {
+		p = ExpandHome(p, home)
+		if p != "" && filepath.IsAbs(p) {
+			if _, ok := registry[p]; ok {
+				continue
+			}
+
+			registry[p] = struct{}{}
+			uniq = append(uniq, p)
+		}
+	}
+
+	return uniq
+}
+
+// Create returns a suitable location relative to which the file with the
+// specified `name` can be written. The first path from the provided `paths`
+// slice which is successfully created (or already exists) is used as a base
+// path for the file. The `name` parameter should contain the name of the file
+// which is going to be written in the location returned by this function, but
+// it can also contain a set of parent directories, which will be created
+// relative to the selected parent path.
+func Create(name string, paths []string) (string, error) {
+	var searchedPaths []string
+	for _, p := range paths {
+		p = filepath.Join(p, name)
+
+		dir := filepath.Dir(p)
+		if Exists(dir) {
+			return p, nil
+		}
+		if err := os.MkdirAll(dir, os.ModeDir|0700); err == nil {
+			return p, nil
+		}
+
+		searchedPaths = append(searchedPaths, dir)
+	}
+
+	return "", fmt.Errorf("could not create any of the following paths: %s",
+		strings.Join(searchedPaths, ", "))
+}
+
+// Search searches for the file with the specified `name` in the provided
+// slice of `paths`. The `name` parameter must contain the name of the file,
+// but it can also contain a set of parent directories.
+func Search(name string, paths []string) (string, error) {
+	var searchedPaths []string
+	for _, p := range paths {
+		p = filepath.Join(p, name)
+		if Exists(p) {
+			return p, nil
+		}
+
+		searchedPaths = append(searchedPaths, filepath.Dir(p))
+	}
+
+	return "", fmt.Errorf("could not locate `%s` in any of the following paths: %s",
+		filepath.Base(name), strings.Join(searchedPaths, ", "))
+}

internal/pathutil/pathutil_plan9.go

@@ -0,0 +1,29 @@
+package pathutil
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// Exists returns true if the specified path exists.
+func Exists(path string) bool {
+	_, err := os.Stat(path)
+	return err == nil || os.IsExist(err)
+}
+
+// ExpandHome substitutes `~` and `$home` at the start of the specified
+// `path` using the provided `home` location.
+func ExpandHome(path, home string) string {
+	if path == "" || home == "" {
+		return path
+	}
+	if path[0] == '~' {
+		return filepath.Join(home, path[1:])
+	}
+	if strings.HasPrefix(path, "$home") {
+		return filepath.Join(home, path[5:])
+	}
+
+	return path
+}

internal/pathutil/pathutil_plan9_test.go

@@ -0,0 +1,52 @@
+//go:build plan9
+// +build plan9
+
+package pathutil_test
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/adrg/xdg/internal/pathutil"
+	"github.com/stretchr/testify/require"
+)
+
+func TestExpandHome(t *testing.T) {
+	home := "/home/test"
+
+	require.Equal(t, home, pathutil.ExpandHome("~", home))
+	require.Equal(t, home, pathutil.ExpandHome("$home", home))
+	require.Equal(t, filepath.Join(home, "appname"), pathutil.ExpandHome("~/appname", home))
+	require.Equal(t, filepath.Join(home, "appname"), pathutil.ExpandHome("$home/appname", home))
+
+	require.Equal(t, "", pathutil.ExpandHome("", home))
+	require.Equal(t, home, pathutil.ExpandHome(home, ""))
+	require.Equal(t, "", pathutil.ExpandHome("", ""))
+
+	require.Equal(t, home, pathutil.ExpandHome(home, home))
+	require.Equal(t, "/", pathutil.ExpandHome("~", "/"))
+	require.Equal(t, "/", pathutil.ExpandHome("$home", "/"))
+	require.Equal(t, "/usr/bin", pathutil.ExpandHome("~/bin", "/usr"))
+	require.Equal(t, "/usr/bin", pathutil.ExpandHome("$home/bin", "/usr"))
+}
+
+func TestUnique(t *testing.T) {
+	input := []string{
+		"",
+		"/home",
+		"/home/test",
+		"a",
+		"~/appname",
+		"$home/appname",
+		"a",
+		"/home",
+	}
+
+	expected := []string{
+		"/home",
+		"/home/test",
+		"/home/test/appname",
+	}
+
+	require.EqualValues(t, expected, pathutil.Unique(input, "/home/test"))
+}

internal/pathutil/pathutil_test.go

@@ -0,0 +1,108 @@
+package pathutil_test
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/adrg/xdg/internal/pathutil"
+	"github.com/stretchr/testify/require"
+)
+
+func TestExists(t *testing.T) {
+	tempDir := os.TempDir()
+
+	// Test regular file.
+	pathFile := filepath.Join(tempDir, "regular")
+	f, err := os.Create(pathFile)
+	require.NoError(t, err)
+	require.NoError(t, f.Close())
+	require.True(t, pathutil.Exists(pathFile))
+
+	// Test symlink.
+	pathSymlink := filepath.Join(tempDir, "symlink")
+	require.NoError(t, os.Symlink(pathFile, pathSymlink))
+	require.True(t, pathutil.Exists(pathSymlink))
+
+	// Test non-existent file.
+	require.NoError(t, os.Remove(pathFile))
+	require.False(t, pathutil.Exists(pathFile))
+	require.False(t, pathutil.Exists(pathSymlink))
+	require.NoError(t, os.Remove(pathSymlink))
+	require.False(t, pathutil.Exists(pathSymlink))
+}
+
+func TestCreate(t *testing.T) {
+	tempDir := os.TempDir()
+
+	// Test path selection order.
+	p, err := pathutil.Create("test", []string{tempDir, "\000a"})
+	require.NoError(t, err)
+	require.Equal(t, filepath.Join(tempDir, "test"), p)
+
+	p, err = pathutil.Create("test", []string{"\000a", tempDir})
+	require.NoError(t, err)
+	require.Equal(t, filepath.Join(tempDir, "test"), p)
+
+	// Test relative parent directories.
+	expected := filepath.Join(tempDir, "appname", "config", "test")
+	p, err = pathutil.Create(filepath.Join("appname", "config", "test"), []string{"\000a", tempDir})
+	require.NoError(t, err)
+	require.Equal(t, expected, p)
+	require.NoError(t, os.RemoveAll(filepath.Dir(expected)))
+
+	expected = filepath.Join(tempDir, "appname", "test")
+	p, err = pathutil.Create(filepath.Join("appname", "test"), []string{"\000a", tempDir})
+	require.NoError(t, err)
+	require.Equal(t, expected, p)
+	require.NoError(t, os.RemoveAll(filepath.Dir(expected)))
+
+	// Test invalid paths.
+	_, err = pathutil.Create(filepath.Join("appname", "test"), []string{"\000a"})
+	require.Error(t, err)
+
+	_, err = pathutil.Create("test", []string{filepath.Join(tempDir, "\000a")})
+	require.Error(t, err)
+}
+
+func TestSearch(t *testing.T) {
+	tempDir := os.TempDir()
+
+	// Test file not found.
+	_, err := pathutil.Search("test", []string{tempDir, filepath.Join(tempDir, "appname")})
+	require.Error(t, err)
+
+	// Test file found.
+	expected := filepath.Join(tempDir, "test")
+	f, err := os.Create(expected)
+	require.NoError(t, err)
+	require.NoError(t, f.Close())
+
+	p, err := pathutil.Search("test", []string{tempDir})
+	require.NoError(t, err)
+	require.Equal(t, expected, p)
+
+	p, err = pathutil.Search("test", []string{filepath.Join(tempDir, "appname"), tempDir})
+	require.NoError(t, err)
+	require.Equal(t, expected, p)
+
+	require.NoError(t, os.Remove(expected))
+
+	// Test relative parent directories.
+	expected = filepath.Join(tempDir, "appname", "test")
+	_, err = pathutil.Create(filepath.Join("appname", "test"), []string{tempDir})
+	require.NoError(t, err)
+	f, err = os.Create(expected)
+	require.NoError(t, err)
+	require.NoError(t, f.Close())
+
+	p, err = pathutil.Search(filepath.Join("appname", "test"), []string{tempDir})
+	require.NoError(t, err)
+	require.Equal(t, expected, p)
+
+	p, err = pathutil.Search("test", []string{tempDir, filepath.Join(tempDir, "appname")})
+	require.NoError(t, err)
+	require.Equal(t, expected, p)
+
+	require.NoError(t, os.RemoveAll(filepath.Dir(expected)))
+}

internal/pathutil/pathutil_unix.go

@@ -0,0 +1,32 @@
+//go:build aix || darwin || dragonfly || freebsd || (js && wasm) || nacl || linux || netbsd || openbsd || solaris
+// +build aix darwin dragonfly freebsd js,wasm nacl linux netbsd openbsd solaris
+
+package pathutil
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// Exists returns true if the specified path exists.
+func Exists(path string) bool {
+	_, err := os.Stat(path)
+	return err == nil || os.IsExist(err)
+}
+
+// ExpandHome substitutes `~` and `$HOME` at the start of the specified
+// `path` using the provided `home` location.
+func ExpandHome(path, home string) string {
+	if path == "" || home == "" {
+		return path
+	}
+	if path[0] == '~' {
+		return filepath.Join(home, path[1:])
+	}
+	if strings.HasPrefix(path, "$HOME") {
+		return filepath.Join(home, path[5:])
+	}
+
+	return path
+}