system/dispatcher: wrap syscall helper functions

This allows tests to stub all kernel behaviour, like in the container package.

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

system/dispatcher_test.go

@@ -0,0 +1,215 @@
+package system
+
+import (
+	"reflect"
+	"slices"
+	"testing"
+
+	"hakurei.app/container/stub"
+	"hakurei.app/system/acl"
+)
+
+// call initialises a [stub.Call].
+// This keeps composites analysis happy without making the test cases too bloated.
+func call(name string, args stub.ExpectArgs, ret any, err error) stub.Call {
+	return stub.Call{Name: name, Args: args, Ret: ret, Err: err}
+}
+
+type opBehaviourTestCase struct {
+	name string
+	uid  int
+	ec   Enablement
+	op   Op
+
+	apply        []stub.Call
+	wantErrApply error
+
+	revert        []stub.Call
+	wantErrRevert error
+}
+
+func checkOpBehaviour(t *testing.T, testCases []opBehaviourTestCase) {
+	t.Helper()
+
+	t.Run("behaviour", func(t *testing.T) {
+		t.Helper()
+
+		for _, tc := range testCases {
+			t.Run(tc.name, func(t *testing.T) {
+				t.Helper()
+
+				var ec *Criteria
+				if tc.ec != 0xff {
+					ec = (*Criteria)(&tc.ec)
+				}
+
+				defer stub.HandleExit()
+				sys, s := InternalNew(t, stub.Expect{Calls: slices.Concat(tc.apply, []stub.Call{{Name: stub.CallSeparator}}, tc.revert)}, tc.uid)
+				errApply := tc.op.apply(sys)
+				s.Expects(stub.CallSeparator)
+				if !reflect.DeepEqual(errApply, tc.wantErrApply) {
+					t.Errorf("apply: error = %v, want %v", errApply, tc.wantErrApply)
+				}
+				if errApply != nil {
+					goto out
+				}
+
+				if err := tc.op.revert(sys, ec); !reflect.DeepEqual(err, tc.wantErrRevert) {
+					t.Errorf("revert: error = %v, want %v", err, tc.wantErrRevert)
+				}
+
+			out:
+				s.VisitIncomplete(func(s *stub.Stub[syscallDispatcher]) {
+					count := s.Pos() - 1 // separator
+					if count < len(tc.apply) {
+						t.Errorf("apply: %d calls, want %d", count, len(tc.apply))
+					} else {
+						t.Errorf("revert: %d calls, want %d", count-len(tc.apply), len(tc.revert))
+					}
+				})
+			})
+		}
+	})
+}
+
+type opsBuilderTestCase struct {
+	name string
+	uid  int
+	f    func(sys *I)
+	want []Op
+	exp  stub.Expect
+}
+
+func checkOpsBuilder(t *testing.T, fname string, testCases []opsBuilderTestCase) {
+	t.Helper()
+
+	t.Run("build", func(t *testing.T) {
+		t.Helper()
+
+		for _, tc := range testCases {
+			t.Run(tc.name, func(t *testing.T) {
+				t.Helper()
+
+				defer stub.HandleExit()
+				sys, s := InternalNew(t, tc.exp, tc.uid)
+				tc.f(sys)
+				s.VisitIncomplete(func(s *stub.Stub[syscallDispatcher]) {
+					t.Helper()
+
+					t.Errorf("%s: %d calls, want %d", fname, s.Pos(), s.Len())
+				})
+				if !slices.EqualFunc(sys.ops, tc.want, func(op Op, v Op) bool { return op.Is(v) }) {
+					t.Errorf("ops: %#v, want %#v", sys.ops, tc.want)
+				}
+			})
+		}
+	})
+}
+
+type opIsTestCase struct {
+	name  string
+	op, v Op
+	want  bool
+}
+
+func checkOpIs(t *testing.T, testCases []opIsTestCase) {
+	t.Helper()
+
+	t.Run("is", func(t *testing.T) {
+		t.Helper()
+
+		for _, tc := range testCases {
+			t.Run(tc.name, func(t *testing.T) {
+				t.Helper()
+
+				if got := tc.op.Is(tc.v); got != tc.want {
+					t.Errorf("Is: %v, want %v", got, tc.want)
+				}
+			})
+		}
+	})
+}
+
+type opMetaTestCase struct {
+	name string
+	op   Op
+
+	wantType   Enablement
+	wantPath   string
+	wantString string
+}
+
+func checkOpMeta(t *testing.T, testCases []opMetaTestCase) {
+	t.Helper()
+
+	t.Run("meta", func(t *testing.T) {
+		t.Helper()
+
+		for _, tc := range testCases {
+			t.Run(tc.name, func(t *testing.T) {
+				t.Helper()
+
+				t.Run("type", func(t *testing.T) {
+					t.Helper()
+
+					if got := tc.op.Type(); got != tc.wantType {
+						t.Errorf("Type: %q, want %q", got, tc.wantType)
+					}
+				})
+
+				t.Run("path", func(t *testing.T) {
+					t.Helper()
+
+					if got := tc.op.Path(); got != tc.wantPath {
+						t.Errorf("Path: %q, want %q", got, tc.wantPath)
+					}
+				})
+
+				t.Run("string", func(t *testing.T) {
+					t.Helper()
+
+					if got := tc.op.String(); got != tc.wantString {
+						t.Errorf("String: %s, want %s", got, tc.wantString)
+					}
+				})
+			})
+		}
+	})
+}
+
+// InternalNew initialises [I] with a stub syscallDispatcher.
+func InternalNew(t *testing.T, want stub.Expect, uid int) (*I, *stub.Stub[syscallDispatcher]) {
+	k := stub.New(t, func(s *stub.Stub[syscallDispatcher]) syscallDispatcher { return &kstub{s} }, want)
+	sys := New(t.Context(), uid)
+	sys.syscallDispatcher = &kstub{k}
+	return sys, k
+}
+
+type kstub struct{ *stub.Stub[syscallDispatcher] }
+
+func (k *kstub) new(f func(k syscallDispatcher)) { k.Helper(); k.New(f) }
+
+func (k *kstub) aclUpdate(name string, uid int, perms ...acl.Perm) error {
+	k.Helper()
+	return k.Expects("aclUpdate").Error(
+		stub.CheckArg(k.Stub, "name", name, 0),
+		stub.CheckArg(k.Stub, "uid", uid, 1),
+		stub.CheckArgReflect(k.Stub, "perms", perms, 2))
+}
+
+func (k *kstub) verbose(v ...any) {
+	k.Helper()
+	if k.Expects("verbose").Error(
+		stub.CheckArgReflect(k.Stub, "v", v, 0)) != nil {
+		k.FailNow()
+	}
+}
+
+func (k *kstub) verbosef(format string, v ...any) {
+	k.Helper()
+	if k.Expects("verbosef").Error(
+		stub.CheckArg(k.Stub, "format", format, 0),
+		stub.CheckArgReflect(k.Stub, "v", v, 1)) != nil {
+		k.FailNow()
+	}
+}