internal/app/hsu: check behaviour

The stub exec.ExitError is hairy as usual, but internal/app is not cross-platform, so this is okay.

Signed-off-by: Ophestra <cat@gensokyo.uk>

1 files changed, 84 insertions, 0 deletions

diff --git a/internal/app/hsu_test.go b/internal/app/hsu_test.go
new file mode 100644
index 00000000..fad724da
--- /dev/null
+++ b/internal/app/hsu_test.go
@@ -0,0 +1,84 @@
+package app
+
+import (
+	"os"
+	"os/exec"
+	"reflect"
+	"strconv"
+	"syscall"
+	"testing"
+	"unsafe"
+
+	"hakurei.app/container/stub"
+	"hakurei.app/hst"
+)
+
+func TestHsu(t *testing.T) {
+	t.Parallel()
+
+	t.Run("ensure dispatcher", func(t *testing.T) {
+		hsu := new(Hsu)
+		hsu.ensureDispatcher()
+
+		k := direct{}
+		if !reflect.DeepEqual(hsu.k, k) {
+			t.Errorf("ensureDispatcher: k = %#v, want %#v", hsu.k, k)
+		}
+	})
+
+	fCheckID := func(k *kstub) error {
+		hsu := &Hsu{k: k}
+		id, err := hsu.ID()
+		k.Verbose(id)
+		if id0, err0 := hsu.ID(); id0 != id || !reflect.DeepEqual(err0, err) {
+			t.Fatalf("ID: id0 = %d, err0 = %#v, id = %d, err = %#v", id0, err0, id, err)
+		}
+		return err
+	}
+
+	checkSimple(t, "Hsu.ID", []simpleTestCase{
+		{"hsu nonexistent", fCheckID, stub.Expect{Calls: []stub.Call{
+			call("mustHsuPath", stub.ExpectArgs{}, m("/run/wrappers/bin/hsu"), nil),
+			call("cmdOutput", stub.ExpectArgs{"/run/wrappers/bin/hsu", os.Stderr, []string{}, "/"}, ([]byte)(nil), os.ErrNotExist),
+			call("verbose", stub.ExpectArgs{[]any{-1}}, nil, nil),
+		}}, &hst.AppError{
+			Step: "obtain uid from hsu",
+			Err:  os.ErrNotExist,
+			Msg:  "the setuid helper is missing: /run/wrappers/bin/hsu",
+		}},
+
+		{"access", fCheckID, stub.Expect{Calls: []stub.Call{
+			call("mustHsuPath", stub.ExpectArgs{}, m("/run/wrappers/bin/hsu"), nil),
+			call("cmdOutput", stub.ExpectArgs{"/run/wrappers/bin/hsu", os.Stderr, []string{}, "/"}, ([]byte)(nil), makeExitError(1<<8)),
+			call("verbose", stub.ExpectArgs{[]any{-1}}, nil, nil),
+		}}, &hst.AppError{
+			Step: "obtain uid from hsu",
+			Err:  ErrHsuAccess,
+		}},
+
+		{"invalid output", fCheckID, stub.Expect{Calls: []stub.Call{
+			call("mustHsuPath", stub.ExpectArgs{}, m("/run/wrappers/bin/hsu"), nil),
+			call("cmdOutput", stub.ExpectArgs{"/run/wrappers/bin/hsu", os.Stderr, []string{}, "/"}, []byte{0}, nil),
+			call("verbose", stub.ExpectArgs{[]any{0}}, nil, nil),
+		}}, &hst.AppError{
+			Step: "obtain uid from hsu",
+			Err:  &strconv.NumError{Func: "Atoi", Num: "\x00", Err: strconv.ErrSyntax},
+			Msg:  "invalid uid string from hsu",
+		}},
+
+		{"success", fCheckID, stub.Expect{Calls: []stub.Call{
+			call("mustHsuPath", stub.ExpectArgs{}, m("/run/wrappers/bin/hsu"), nil),
+			call("cmdOutput", stub.ExpectArgs{"/run/wrappers/bin/hsu", os.Stderr, []string{}, "/"}, []byte{'0'}, nil),
+			call("verbose", stub.ExpectArgs{[]any{0}}, nil, nil),
+		}}, nil},
+	})
+}
+
+// makeExitError populates syscall.WaitStatus in an [exec.ExitError].
+// Do not reuse this function in a cross-platform package.
+func makeExitError(status syscall.WaitStatus) error {
+	ps := new(os.ProcessState)
+	statusV := reflect.ValueOf(ps).Elem().FieldByName("status")
+	*reflect.NewAt(statusV.Type(), unsafe.Pointer(statusV.UnsafeAddr())).Interface().(*syscall.WaitStatus) = status
+	return &exec.ExitError{ProcessState: ps}
+}