try some more tsting

internal/fswatcher/inotify/inotify_test.go

@@ -0,0 +1,49 @@
+package inotify
+
+import (
+	"errors"
+	"testing"
+)
+
+func TestNewInotify(t *testing.T) {
+	mis := &MockInotifySyscalls{fd: 1}
+
+	i, err := NewInotify(mis)
+	if err != nil {
+		t.Fatalf("Unexpected error")
+	}
+	if i.FD != mis.fd {
+		t.Fatalf("Did not set FD of inotify object")
+	}
+}
+
+func TestNewInotifyError(t *testing.T) {
+	mis := &MockInotifySyscalls{fd: -1}
+
+	_, err := NewInotify(mis)
+	if err == nil || err.Error() != "initializing inotify: syscall error" {
+		t.Fatalf("Expected syscall error but did not get: %v", err)
+	}
+}
+
+// mock
+
+type MockInotifySyscalls struct {
+	fd int
+}
+
+func (mis *MockInotifySyscalls) Init() (int, error) {
+	if mis.fd >= 0 {
+		return mis.fd, nil
+	} else {
+		return -1, errors.New("syscall error")
+	}
+}
+
+func (mis *MockInotifySyscalls) AddWatch(fd int, dir string) (int, error) {
+	return 2, nil
+}
+
+func (mis *MockInotifySyscalls) Close(fd int) error {
+	return nil
+}