system: sys comparison method

Signed-off-by: Ophestra Umiker <cat@ophivana.moe>

internal/system/op.go

@@ -65,6 +65,20 @@ func (sys *I) UID() int {
 	return sys.uid
 }
 
+func (sys *I) Equal(v *I) bool {
+	if v == nil || sys.uid != v.uid || len(sys.ops) != len(v.ops) {
+		return false
+	}
+
+	for i, o := range sys.ops {
+		if !o.Is(v.ops[i]) {
+			return false
+		}
+	}
+
+	return true
+}
+
 func (sys *I) Commit() error {
 	sys.lock.Lock()
 	defer sys.lock.Unlock()

internal/system/op_test.go

@@ -51,3 +51,79 @@ func TestTypeString(t *testing.T) {
 		})
 	}
 }
+
+func TestI_Equal(t *testing.T) {
+	testCases := []struct {
+		name string
+		sys  *system.I
+		v    *system.I
+		want bool
+	}{
+		{
+			"simple UID",
+			system.New(150),
+			system.New(150),
+			true,
+		},
+		{
+			"simple UID differ",
+			system.New(150),
+			system.New(151),
+			false,
+		},
+		{
+			"simple UID nil",
+			system.New(150),
+			nil,
+			false,
+		},
+		{
+			"op length mismatch",
+			system.New(150).
+				ChangeHosts("chronos"),
+			system.New(150).
+				ChangeHosts("chronos").
+				Ensure("/run", 0755),
+			false,
+		},
+		{
+			"op value mismatch",
+			system.New(150).
+				ChangeHosts("chronos").
+				Ensure("/run", 0644),
+			system.New(150).
+				ChangeHosts("chronos").
+				Ensure("/run", 0755),
+			false,
+		},
+		{
+			"op type mismatch",
+			system.New(150).
+				ChangeHosts("chronos").
+				CopyFile("/tmp/fortify.1971/30c9543e0a2c9621a8bfecb9d874c347/pulse-cookie", "/home/ophestra/xdg/config/pulse/cookie"),
+			system.New(150).
+				ChangeHosts("chronos").
+				Ensure("/run", 0755),
+			false,
+		},
+		{
+			"op equals",
+			system.New(150).
+				ChangeHosts("chronos").
+				Ensure("/run", 0755),
+			system.New(150).
+				ChangeHosts("chronos").
+				Ensure("/run", 0755),
+			true,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			if tc.sys.Equal(tc.v) != tc.want {
+				t.Errorf("Equal: got %v; want %v",
+					!tc.want, tc.want)
+			}
+		})
+	}
+}