helper: test child process handling

The stub child process simulates reading from the argument fd and copies the entire payload unmodified to stdout. If status pipe is enabled it will simulate sync fd behaviour as well.

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

helper/args_test.go

@@ -0,0 +1,29 @@
+package helper_test
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+	"testing"
+
+	"git.ophivana.moe/cat/fortify/helper"
+)
+
+func Test_argsFD_String(t *testing.T) {
+	argsOnce.Do(prepareArgs)
+
+	wantString := strings.Join(want, " ")
+	if got := argsWt.(fmt.Stringer).String(); got != wantString {
+		t.Errorf("String(): got %v; want %v",
+			got, wantString)
+	}
+}
+
+func TestNewCheckedArgs(t *testing.T) {
+	args := []string{"\x00"}
+	if _, err := helper.NewCheckedArgs(args); !errors.Is(err, helper.ErrContainsNull) {
+		t.Errorf("NewCheckedArgs(%q) error = %v, wantErr %v",
+			args,
+			err, helper.ErrContainsNull)
+	}
+}

helper/helper_test.go

@@ -0,0 +1,182 @@
+package helper_test
+
+import (
+	"io"
+	"strings"
+	"sync"
+	"testing"
+
+	"git.ophivana.moe/cat/fortify/helper"
+)
+
+var (
+	want = []string{
+		"unix:path=/run/dbus/system_bus_socket",
+		"/tmp/fortify.1971/12622d846cc3fe7b4c10359d01f0eb47/system_bus_socket",
+		"--filter",
+		"--talk=org.bluez",
+		"--talk=org.freedesktop.Avahi",
+		"--talk=org.freedesktop.UPower",
+	}
+
+	wantPayload string
+	argsWt      io.WriterTo
+	argsOnce    sync.Once
+)
+
+func prepareArgs() {
+	wantPayload = strings.Join(want, "\x00") + "\x00"
+
+	if a, err := helper.NewCheckedArgs(want); err != nil {
+		panic(err.Error())
+	} else {
+		argsWt = a
+	}
+}
+
+func TestHelper_StartNotify_Close_Wait(t *testing.T) {
+	helper.ReplaceExecCommand(t)
+	argsOnce.Do(prepareArgs)
+
+	t.Run("start helper with status channel", func(t *testing.T) {
+		h := helper.New(argsWt, "crash-test-dummy", "--args=3", "--fd=4")
+		ready := make(chan error, 1)
+
+		stdout, stderr := new(strings.Builder), new(strings.Builder)
+		h.Stdout, h.Stderr = stdout, stderr
+
+		t.Run("wait not yet started helper", func(t *testing.T) {
+			wantErr := "exec: not started"
+			if err := h.Wait(); err != nil && err.Error() != wantErr {
+				t.Errorf("Wait(%v) error = %v, wantErr %v",
+					ready,
+					err, wantErr)
+				return
+			}
+		})
+
+		if err := h.StartNotify(ready); err != nil {
+			t.Errorf("StartNotify(%v) error = %v",
+				ready,
+				err)
+			return
+		}
+
+		t.Run("start already started helper", func(t *testing.T) {
+			wantErr := "exec: already started"
+			if err := h.StartNotify(ready); err != nil && err.Error() != wantErr {
+				t.Errorf("StartNotify(%v) error = %v, wantErr %v",
+					ready,
+					err, wantErr)
+				return
+			}
+		})
+
+		if err := <-ready; err != nil {
+			t.Errorf("StartNotify(%v) latent error = %v",
+				ready,
+				err)
+		}
+
+		if err := h.Close(); err != nil {
+			t.Errorf("Close() error = %v",
+				err)
+		}
+
+		if err := h.Wait(); err != nil {
+			t.Errorf("Wait() err = %v stderr = %s",
+				err, stderr)
+		}
+
+		t.Run("wait already finalised helper", func(t *testing.T) {
+			wantErr := "exec: Wait was already called"
+			if err := h.Wait(); err != nil && err.Error() != wantErr {
+				t.Errorf("Wait(%v) error = %v, wantErr %v",
+					ready,
+					err, wantErr)
+				return
+			}
+		})
+
+		if got := stdout.String(); !strings.HasPrefix(got, wantPayload) {
+			t.Errorf("StartNotify(%v) stdout = %v, want %v",
+				ready,
+				got, wantPayload)
+		}
+	})
+}
+func TestHelper_Start_Close_Wait(t *testing.T) {
+	helper.ReplaceExecCommand(t)
+	argsOnce.Do(prepareArgs)
+
+	var wt io.WriterTo
+	if a, err := helper.NewCheckedArgs(want); err != nil {
+		t.Errorf("NewCheckedArgs(%q) error = %v",
+			want,
+			err)
+		return
+	} else {
+		wt = a
+	}
+
+	t.Run("start helper", func(t *testing.T) {
+		h := helper.New(wt, "crash-test-dummy", "--args=3")
+
+		stdout, stderr := new(strings.Builder), new(strings.Builder)
+		h.Stdout, h.Stderr = stdout, stderr
+
+		if err := h.Start(); err != nil {
+			t.Errorf("Start() error = %v",
+				err)
+			return
+		}
+
+		t.Run("close helper without status pipe", func(t *testing.T) {
+			defer func() {
+				wantPanic := "attempted to close helper with no status pipe"
+				if r := recover(); r != wantPanic {
+					t.Errorf("Close() panic = %v, wantPanic %v",
+						r, wantPanic)
+				}
+			}()
+			if err := h.Close(); err != nil {
+				t.Errorf("Close() error = %v",
+					err)
+				return
+			}
+		})
+
+		if err := h.Wait(); err != nil {
+			t.Errorf("Wait() err = %v stderr = %s",
+				err, stderr)
+		}
+
+		if got := stdout.String(); !strings.HasPrefix(got, wantPayload) {
+			t.Errorf("Start() stdout = %v, want %v",
+				got, wantPayload)
+		}
+	})
+}
+
+func TestNew(t *testing.T) {
+	t.Run("valid new helper nil check", func(t *testing.T) {
+		swt, _ := helper.NewCheckedArgs(make([]string, 1))
+		if got := helper.New(swt, "fortify"); got == nil {
+			t.Errorf("New(%q, %q) got nil",
+				swt, "fortify")
+			return
+		}
+	})
+
+	t.Run("invalid new helper panic", func(t *testing.T) {
+		defer func() {
+			want := "attempted to create helper with invalid argument writer"
+			if r := recover(); r != want {
+				t.Errorf("New: panic = %q, want %q",
+					r, want)
+			}
+		}()
+
+		helper.New(nil, "fortify")
+	})
+}