hst/enablement: editor friendly enablement adaptor

Having the bit field value here (in decimal, no less) is unfriendly to text editors. Use a bunch of booleans here to improve ease of use.

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

5 files changed, 184 insertions, 4 deletions

diff --git a/hst/config.go b/hst/config.go
index c34ecb1e..44d36380 100644
--- a/hst/config.go
+++ b/hst/config.go
@@ -3,7 +3,6 @@ package hst
 
 import (
 	"hakurei.app/container"
-	"hakurei.app/system"
 	"hakurei.app/system/dbus"
 )
 
@@ -24,7 +23,7 @@ type Config struct {
 	Args []string `json:"args"`
 
 	// system services to make available in the container
-	Enablements system.Enablement `json:"enablements"`
+	Enablements *Enablements `json:"enablements,omitempty"`
 
 	// session D-Bus proxy configuration;
 	// nil makes session bus proxy assume built-in defaults
diff --git a/hst/enablement.go b/hst/enablement.go
new file mode 100644
index 00000000..021288b3
--- /dev/null
+++ b/hst/enablement.go
@@ -0,0 +1,69 @@
+package hst
+
+import (
+	"encoding/json"
+	"syscall"
+
+	"hakurei.app/system"
+)
+
+// NewEnablements returns the address of [system.Enablement] as [Enablements].
+func NewEnablements(e system.Enablement) *Enablements { return (*Enablements)(&e) }
+
+// enablementsJSON is the [json] representation of the [system.Enablement] bit field.
+type enablementsJSON struct {
+	Wayland bool `json:"wayland,omitempty"`
+	X11     bool `json:"x11,omitempty"`
+	DBus    bool `json:"dbus,omitempty"`
+	Pulse   bool `json:"pulse,omitempty"`
+}
+
+// Enablements is the [json] adapter for [system.Enablement].
+type Enablements system.Enablement
+
+// Unwrap returns the underlying [system.Enablement].
+func (e *Enablements) Unwrap() system.Enablement {
+	if e == nil {
+		return 0
+	}
+	return system.Enablement(*e)
+}
+
+func (e *Enablements) MarshalJSON() ([]byte, error) {
+	if e == nil {
+		return nil, syscall.EINVAL
+	}
+	return json.Marshal(&enablementsJSON{
+		Wayland: system.Enablement(*e)&system.EWayland != 0,
+		X11:     system.Enablement(*e)&system.EX11 != 0,
+		DBus:    system.Enablement(*e)&system.EDBus != 0,
+		Pulse:   system.Enablement(*e)&system.EPulse != 0,
+	})
+}
+
+func (e *Enablements) UnmarshalJSON(data []byte) error {
+	if e == nil {
+		return syscall.EINVAL
+	}
+
+	v := new(enablementsJSON)
+	if err := json.Unmarshal(data, &v); err != nil {
+		return err
+	}
+
+	var ve system.Enablement
+	if v.Wayland {
+		ve |= system.EWayland
+	}
+	if v.X11 {
+		ve |= system.EX11
+	}
+	if v.DBus {
+		ve |= system.EDBus
+	}
+	if v.Pulse {
+		ve |= system.EPulse
+	}
+	*e = Enablements(ve)
+	return nil
+}
diff --git a/hst/enablement_test.go b/hst/enablement_test.go
new file mode 100644
index 00000000..c132dd37
--- /dev/null
+++ b/hst/enablement_test.go
@@ -0,0 +1,108 @@
+package hst_test
+
+import (
+	"encoding/json"
+	"errors"
+	"syscall"
+	"testing"
+
+	"hakurei.app/hst"
+	"hakurei.app/system"
+)
+
+func TestEnablements(t *testing.T) {
+	testCases := []struct {
+		name  string
+		e     *hst.Enablements
+		data  string
+		sData string
+	}{
+		{"nil", nil, "null", `{"value":null,"magic":3236757504}`},
+		{"zero", hst.NewEnablements(0), `{}`, `{"value":{},"magic":3236757504}`},
+		{"wayland", hst.NewEnablements(system.EWayland), `{"wayland":true}`, `{"value":{"wayland":true},"magic":3236757504}`},
+		{"x11", hst.NewEnablements(system.EX11), `{"x11":true}`, `{"value":{"x11":true},"magic":3236757504}`},
+		{"dbus", hst.NewEnablements(system.EDBus), `{"dbus":true}`, `{"value":{"dbus":true},"magic":3236757504}`},
+		{"pulse", hst.NewEnablements(system.EPulse), `{"pulse":true}`, `{"value":{"pulse":true},"magic":3236757504}`},
+		{"all", hst.NewEnablements(system.EWayland | system.EX11 | system.EDBus | system.EPulse), `{"wayland":true,"x11":true,"dbus":true,"pulse":true}`, `{"value":{"wayland":true,"x11":true,"dbus":true,"pulse":true},"magic":3236757504}`},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Run("marshal", func(t *testing.T) {
+				if got, err := json.Marshal(tc.e); err != nil {
+					t.Fatalf("Marshal: error = %v", err)
+				} else if string(got) != tc.data {
+					t.Errorf("Marshal:\n%s, want\n%s", string(got), tc.data)
+				}
+
+				if got, err := json.Marshal(struct {
+					Value *hst.Enablements `json:"value"`
+					Magic int              `json:"magic"`
+				}{tc.e, syscall.MS_MGC_VAL}); err != nil {
+					t.Fatalf("Marshal: error = %v", err)
+				} else if string(got) != tc.sData {
+					t.Errorf("Marshal:\n%s, want\n%s", string(got), tc.sData)
+				}
+			})
+
+			t.Run("unmarshal", func(t *testing.T) {
+				{
+					got := new(hst.Enablements)
+					if err := json.Unmarshal([]byte(tc.data), &got); err != nil {
+						t.Fatalf("Unmarshal: error = %v", err)
+					}
+					if tc.e == nil {
+						if got != nil {
+							t.Errorf("Unmarshal: %v", got)
+						}
+					} else if *got != *tc.e {
+						t.Errorf("Unmarshal: %v, want %v", got, tc.e)
+					}
+				}
+
+				{
+					got := *(new(struct {
+						Value *hst.Enablements `json:"value"`
+						Magic int              `json:"magic"`
+					}))
+					if err := json.Unmarshal([]byte(tc.sData), &got); err != nil {
+						t.Fatalf("Unmarshal: error = %v", err)
+					}
+					if tc.e == nil {
+						if got.Value != nil {
+							t.Errorf("Unmarshal: %v", got)
+						}
+					} else if *got.Value != *tc.e {
+						t.Errorf("Unmarshal: %v, want %v", got.Value, tc.e)
+					}
+				}
+			})
+		})
+	}
+
+	t.Run("unwrap", func(t *testing.T) {
+		t.Run("nil", func(t *testing.T) {
+			if got := (*hst.Enablements)(nil).Unwrap(); got != 0 {
+				t.Errorf("Unwrap: %v", got)
+			}
+		})
+
+		t.Run("val", func(t *testing.T) {
+			if got := hst.NewEnablements(system.EWayland | system.EPulse).Unwrap(); got != system.EWayland|system.EPulse {
+				t.Errorf("Unwrap: %v", got)
+			}
+		})
+	})
+
+	t.Run("passthrough", func(t *testing.T) {
+		if _, err := (*hst.Enablements)(nil).MarshalJSON(); !errors.Is(err, syscall.EINVAL) {
+			t.Errorf("MarshalJSON: error = %v", err)
+		}
+		if err := (*hst.Enablements)(nil).UnmarshalJSON(nil); !errors.Is(err, syscall.EINVAL) {
+			t.Errorf("UnmarshalJSON: error = %v", err)
+		}
+		if err := new(hst.Enablements).UnmarshalJSON([]byte{}); err == nil {
+			t.Errorf("UnmarshalJSON: error = %v", err)
+		}
+	})
+}
diff --git a/hst/template.go b/hst/template.go
index 82e0b7d9..ea27fbb4 100644
--- a/hst/template.go
+++ b/hst/template.go
@@ -21,7 +21,7 @@ func Template() *Config {
 			"--ozone-platform=wayland",
 		},
 
-		Enablements: system.EWayland | system.EDBus | system.EPulse,
+		Enablements: NewEnablements(system.EWayland | system.EDBus | system.EPulse),
 
 		SessionBus: &dbus.Config{
 			See: nil,
diff --git a/hst/template_test.go b/hst/template_test.go
index 76933783..31b9013e 100644
--- a/hst/template_test.go
+++ b/hst/template_test.go
@@ -18,7 +18,11 @@ func TestTemplate(t *testing.T) {
 		"--enable-features=UseOzonePlatform",
 		"--ozone-platform=wayland"
 	],
-	"enablements": 13,
+	"enablements": {
+		"wayland": true,
+		"dbus": true,
+		"pulse": true
+	},
 	"session_bus": {
 		"see": null,
 		"talk": [