xdg: add functions to deal with user home paths

These are intended to replace the following deprecated libraries:

	github.com/kyoh86/xdg
	github.com/mitchellh/go-homedir

The feature set should be roughly equivalent with some tweaks to make
our life easier in aerc.

Signed-off-by: Robin Jarry <robin@jarry.cc>
Reviewed-by: Moritz Poldrack <moritz@poldrack.dev>

1 files changed, 88 insertions, 0 deletions

diff --git a/lib/xdg/home_test.go b/lib/xdg/home_test.go
new file mode 100644
index 00000000..673e35b5
--- /dev/null
+++ b/lib/xdg/home_test.go
@@ -0,0 +1,88 @@
+package xdg
+
+import (
+	"errors"
+	"os/user"
+	"testing"
+)
+
+func TestHomeDir(t *testing.T) {
+	t.Run("from env", func(t *testing.T) {
+		t.Setenv("HOME", "/home/user")
+		home := HomeDir()
+		if home != "/home/user" {
+			t.Errorf(`got %q expected "/home/user"`, home)
+		}
+	})
+	t.Run("from getpwuid_r", func(t *testing.T) {
+		t.Setenv("HOME", "")
+		orig := currentUser
+		currentUser = func() (*user.User, error) {
+			return &user.User{HomeDir: "/home/user"}, nil
+		}
+		home := HomeDir()
+		currentUser = orig
+		if home != "/home/user" {
+			t.Errorf(`got %q expected "/home/user"`, home)
+		}
+	})
+	t.Run("failure", func(t *testing.T) {
+		t.Setenv("HOME", "")
+		orig := currentUser
+		currentUser = func() (*user.User, error) {
+			return nil, errors.New("no such user")
+		}
+		home := HomeDir()
+		currentUser = orig
+		if home != "" {
+			t.Errorf(`got %q expected ""`, home)
+		}
+	})
+}
+
+func TestExpandHome(t *testing.T) {
+	t.Setenv("HOME", "/home/user")
+	vectors := []struct {
+		args     []string
+		expected string
+	}{
+		{args: []string{"foo"}, expected: "foo"},
+		{args: []string{"foo", "bar"}, expected: "foo/bar"},
+		{args: []string{"/foobar/baz"}, expected: "/foobar/baz"},
+		{args: []string{"~/foobar/baz"}, expected: "/home/user/foobar/baz"},
+		{args: []string{}, expected: ""},
+		{args: []string{"~"}, expected: "/home/user"},
+	}
+	for _, vec := range vectors {
+		t.Run(vec.expected, func(t *testing.T) {
+			res := ExpandHome(vec.args...)
+			if res != vec.expected {
+				t.Errorf("got %q expected %q", res, vec.expected)
+			}
+		})
+	}
+}
+
+func TestTildeHome(t *testing.T) {
+	t.Setenv("HOME", "/home/user")
+	vectors := []struct {
+		arg      string
+		expected string
+	}{
+		{arg: "foo", expected: "foo"},
+		{arg: "foo/bar", expected: "foo/bar"},
+		{arg: "/foobar/baz", expected: "/foobar/baz"},
+		{arg: "/home/user/foobar/baz", expected: "~/foobar/baz"},
+		{arg: "", expected: ""},
+		{arg: "/home/user", expected: "~"},
+		{arg: "/home/user2/foobar/baz", expected: "/home/user2/foobar/baz"},
+	}
+	for _, vec := range vectors {
+		t.Run(vec.expected, func(t *testing.T) {
+			res := TildeHome(vec.arg)
+			if res != vec.expected {
+				t.Errorf("got %q expected %q", res, vec.expected)
+			}
+		})
+	}
+}