1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139

//! actix-mock-helper is a set of helpers for creating mock actors using the `Mocker` type.
//! That type of actor can be  used to simulate any type of mock you could want, but it's very verbose to interact with.
//! actix-mock helper is especially useful in the case that you have multiple messages in a sequence that you want to mock

use actix::{Actor, Addr, actors::mocker::Mocker};
use std::any::Any;

/// A mock for a sequence of messages sent to the actor
/// Example:
/// ```
/// # use actix::prelude::*;
/// # use actix_mock_helper::MockActorSequence;
/// struct FakeActor;
/// impl Actor for FakeActor {
///     type Context = actix::Context<Self>;
/// }
/// struct Msg1;
/// struct Msg2;
/// impl Message for Msg1 {
///   type Result = i32;
/// }
/// impl Message for Msg2 {
///   type Result = bool;
/// }
///#[actix_rt::main]
/// async fn main() {
///   let mock_actor = MockActorSequence::new()
///     .msg(|_m: &Msg1| 5) // you can access the message sent.
///     .msg::<Msg2, _>(|_m| true) // alternate syntax to specify the message type
///     .build::<FakeActor>();
///   assert_eq!(mock_actor.send(Msg1).await.unwrap(), 5);
///   assert_eq!(mock_actor.send(Msg2).await.unwrap(), true);
/// }
/// ```
pub struct MockActorSequence {
    callbacks: Vec<Box<dyn FnMut(Box<dyn Any>) -> Box<dyn Any>>>,
    current: usize
}

impl MockActorSequence {
    pub fn new() -> Self {
        Self { callbacks: Vec::new(), current: 0 }
    }

    /// Add another message to be expected, and return the result of the callback.
    /// The type of the message is checked at runtime against the expectation,
    /// and the message itself is passed to the callback so that it can be used to build the result
    pub fn msg<Msg: actix::Message, Cb>(mut self, mut cb: Cb) -> Self
        where
        Msg: 'static ,
        Cb: FnMut(&Msg) -> Msg::Result,
        Cb: 'static {
        self.callbacks.push(Box::new(move |raw_msg| {
            let msg = raw_msg.downcast_ref::<Msg>().unwrap();
            let result: <Msg as actix::Message>::Result = cb(msg);
            Box::new(Some(result))
        }));
        self
    }

    /// Fnalize the sequence and build the actor. Returns an `Addr` to the actor.
    /// Must provide the actor type
    pub fn build<A: Actor>(mut self) -> Addr<Mocker<A>> {
        actix::actors::mocker::Mocker::mock(Box::new(move |raw_msg, _ctx| {
            let result = self.callbacks.get_mut(self.current).expect("unexpected message in MockActorSequence::build")(raw_msg);
            self.current += 1;
            result
        })).start()
    }
}

/// reduced boilerplate helper for if you have just a single message you expect.
pub fn simple_mock_actor<A: Actor, Msg: actix::Message, Cb: FnMut(&Msg) -> Msg::Result>(cb: Cb) -> Addr<Mocker<A>>
where
      Msg: 'static,
      Cb: 'static {
  MockActorSequence::new().msg(cb).build()
}

#[cfg(test)]
mod tests {

    use actix::{Actor, Message, actors::mocker::Mocker, Addr};
    use super::*;

    struct FakeActor;

    impl Actor for FakeActor {
        type Context = actix::Context<Self>;
    }

    struct Msg1;
    struct Msg2;

    struct UnknownMessage;

    impl Message for Msg1 {
    type Result = i32;
    }

    impl Message for Msg2 {
    type Result = bool;
    }

    impl Message for UnknownMessage {
    type Result = bool;
    }

    #[actix_rt::test]
    async fn can_mock_sequence() {
    let mock_actor = MockActorSequence::new()
        .msg(|_m: &Msg1| 5)
        .msg(|_m: &Msg2| true)
        .msg(|_m: &Msg1| 42)
        .build::<FakeActor>();

    assert_eq!(mock_actor.send(Msg1).await.unwrap(), 5);
    assert_eq!(mock_actor.send(Msg2).await.unwrap(), true);
    assert_eq!(mock_actor.send(Msg1).await.unwrap(), 42);
    assert!(mock_actor.send(Msg2).await.is_err());
    }

    #[actix_rt::test]
    async fn message_type_must_match() {
    let mock_actor = MockActorSequence::new()
        .msg(|_m: &Msg1| 5)
        .build::<FakeActor>();

    assert!(mock_actor.send(UnknownMessage).await.is_err());
    }

    #[actix_rt::test]
    async fn simple_works() {
    let mock_actor: Addr<Mocker<FakeActor>> = simple_mock_actor(|_m: &Msg1| 5);

    assert_eq!(mock_actor.send(Msg1).await.unwrap(), 5);
    }

}