system: improve tests of the I struct

This cleans up for the test overhaul of this package.

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

system/system_test.go

@@ -1,28 +1,37 @@
 package system_test
 
 import (
+	"reflect"
 	"strconv"
 	"testing"
+	_ "unsafe"
 
 	"hakurei.app/system"
 )
 
-func TestNew(t *testing.T) {
+//go:linkname criteriaHasType hakurei.app/system.(*Criteria).hasType
+func criteriaHasType(_ *system.Criteria, _ system.Enablement) bool
+
+func TestCriteria(t *testing.T) {
 	testCases := []struct {
-		uid int
+		name  string
+		ec, t system.Enablement
+		want  bool
 	}{
-		{150},
-		{149},
-		{148},
-		{147},
+		{"nil", 0xff, system.EWayland, true},
+		{"nil user", 0xff, system.User, false},
+		{"all", system.EWayland | system.EX11 | system.EDBus | system.EPulse | system.User | system.Process, system.Process, true},
 	}
 
 	for _, tc := range testCases {
-		t.Run("sys initialised with uid "+strconv.Itoa(tc.uid), func(t *testing.T) {
-			if got := system.New(t.Context(), tc.uid); got.UID() != tc.uid {
-				t.Errorf("New(%d) uid = %d, want %d",
-					tc.uid,
-					got.UID(), tc.uid)
+		t.Run(tc.name, func(t *testing.T) {
+			var criteria *system.Criteria
+			if tc.ec != 0xff {
+				criteria = (*system.Criteria)(&tc.ec)
+			}
+			if got := criteriaHasType(criteria, tc.t); got != tc.want {
+				t.Errorf("hasType: got %v, want %v",
+					got, tc.want)
 			}
 		})
 	}
@@ -45,86 +54,108 @@ func TestTypeString(t *testing.T) {
 	}
 
 	for _, tc := range testCases {
-		t.Run("label type string "+tc.want, func(t *testing.T) {
+		t.Run("label type string "+strconv.Itoa(int(tc.e)), func(t *testing.T) {
 			if got := system.TypeString(tc.e); got != tc.want {
-				t.Errorf("TypeString: %q, want %q",
-					got, tc.want)
+				t.Errorf("TypeString: %q, want %q", got, tc.want)
 			}
 		})
 	}
 }
 
-func TestI_Equal(t *testing.T) {
+func TestNew(t *testing.T) {
+	t.Run("panic", func(t *testing.T) {
+		t.Run("ctx", func(t *testing.T) {
+			defer func() {
+				want := "invalid call to New"
+				if r := recover(); r != want {
+					t.Errorf("recover: %v, want %v", r, want)
+				}
+			}()
+			system.New(nil, 0)
+		})
+
+		t.Run("uid", func(t *testing.T) {
+			defer func() {
+				want := "invalid call to New"
+				if r := recover(); r != want {
+					t.Errorf("recover: %v, want %v", r, want)
+				}
+			}()
+			system.New(t.Context(), -1)
+		})
+	})
+
+	sys := system.New(t.Context(), 0xdeadbeef)
+	if got := reflect.ValueOf(sys).Elem().FieldByName("ctx"); got.IsNil() {
+		t.Errorf("New: ctx = %#v", got)
+	}
+	if got := sys.UID(); got != 0xdeadbeef {
+		t.Errorf("UID: %d", got)
+	}
+}
+
+func TestEqual(t *testing.T) {
 	testCases := []struct {
 		name string
 		sys  *system.I
 		v    *system.I
 		want bool
 	}{
-		{
-			"simple UID",
+		{"simple UID",
 			system.New(t.Context(), 150),
 			system.New(t.Context(), 150),
-			true,
-		},
-		{
-			"simple UID differ",
+			true},
+
+		{"simple UID differ",
 			system.New(t.Context(), 150),
 			system.New(t.Context(), 151),
-			false,
-		},
-		{
-			"simple UID nil",
+			false},
+
+		{"simple UID nil",
 			system.New(t.Context(), 150),
 			nil,
-			false,
-		},
-		{
-			"op length mismatch",
+			false},
+
+		{"op length mismatch",
 			system.New(t.Context(), 150).
 				ChangeHosts("chronos"),
 			system.New(t.Context(), 150).
 				ChangeHosts("chronos").
 				Ensure("/run", 0755),
-			false,
-		},
-		{
-			"op value mismatch",
+			false},
+
+		{"op value mismatch",
 			system.New(t.Context(), 150).
 				ChangeHosts("chronos").
 				Ensure("/run", 0644),
 			system.New(t.Context(), 150).
 				ChangeHosts("chronos").
 				Ensure("/run", 0755),
-			false,
-		},
-		{
-			"op type mismatch",
+			false},
+
+		{"op type mismatch",
 			system.New(t.Context(), 150).
 				ChangeHosts("chronos").
 				CopyFile(new([]byte), "/home/ophestra/xdg/config/pulse/cookie", 0, 256),
 			system.New(t.Context(), 150).
 				ChangeHosts("chronos").
 				Ensure("/run", 0755),
-			false,
-		},
-		{
-			"op equals",
+			false},
+
+		{"op equals",
 			system.New(t.Context(), 150).
 				ChangeHosts("chronos").
 				Ensure("/run", 0755),
 			system.New(t.Context(), 150).
 				ChangeHosts("chronos").
 				Ensure("/run", 0755),
-			true,
-		},
+			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)
+				t.Errorf("Equal: %v, want %v", !tc.want, tc.want)
 			}
 		})
 	}