aether_evals/agents/
fake_agent.rs

1use super::agent::{Agent, AgentRunResult, RunError};
2use crate::Task;
3use aether_core::events::{AgentEvent, StreamState, TurnOutcome};
4use async_stream::try_stream;
5use futures::Stream;
6use std::path::{Path, PathBuf};
7use tokio::fs::{create_dir_all, write};
8
9#[derive(Clone)]
10pub struct FakeAgent {
11    events: Vec<AgentEvent>,
12    file_writes: Vec<(PathBuf, String)>,
13    workspace: Option<PathBuf>,
14}
15
16impl FakeAgent {
17    pub fn new(events: Vec<AgentEvent>) -> Self {
18        Self { events, file_writes: Vec::new(), workspace: None }
19    }
20
21    pub fn success() -> Self {
22        Self::new(vec![
23            AgentEvent::text("fake_1", "Task completed successfully", StreamState::Complete),
24            AgentEvent::turn_ended(TurnOutcome::Completed),
25        ])
26    }
27
28    pub fn with_tool_call(tool_name: impl Into<String>, result: impl Into<String>) -> Self {
29        Self::new(vec![
30            AgentEvent::tool_result("fake_call_1", &tool_name.into(), "{}", &result.into()),
31            AgentEvent::text("fake_2", "Task completed using tools", StreamState::Complete),
32            AgentEvent::turn_ended(TurnOutcome::Completed),
33        ])
34    }
35
36    pub fn writes_file(path: impl Into<PathBuf>, contents: impl Into<String>) -> Self {
37        Self::success().with_file_write(path, contents)
38    }
39
40    pub fn with_file_write(mut self, path: impl Into<PathBuf>, contents: impl Into<String>) -> Self {
41        self.file_writes.push((path.into(), contents.into()));
42        self
43    }
44
45    pub fn with_workspace(mut self, workspace: impl AsRef<Path>) -> Self {
46        self.workspace = Some(workspace.as_ref().to_path_buf());
47        self
48    }
49}
50
51impl Agent for FakeAgent {
52    fn run(&self, _task: Task) -> impl Stream<Item = AgentRunResult> + Send + '_ {
53        try_stream! {
54            if !self.file_writes.is_empty() && self.workspace.is_none() {
55                Err(RunError::ConfigurationError("FakeAgent file writes require a bound workspace".to_string()))?;
56            }
57
58            for (path, contents) in &self.file_writes {
59                let file_path = self.workspace.as_ref().expect("workspace checked above").join(path);
60                if let Some(parent) = file_path.parent() {
61                    create_dir_all(parent).await.map_err(|error| {
62                        RunError::ExecutionFailed(format!("failed to create fake file parent: {error}"))
63                    })?;
64                }
65                write(&file_path, contents)
66                    .await
67                    .map_err(|error| RunError::ExecutionFailed(format!("failed to write fake file: {error}")))?;
68            }
69
70            for event in &self.events {
71                yield event.clone();
72            }
73        }
74    }
75}
76
77#[cfg(test)]
78mod tests {
79    use super::*;
80    use aether_core::events::{MessageEvent, TurnEvent};
81
82    #[tokio::test]
83    async fn fake_agent_success_sends_done() {
84        let agent = FakeAgent::success();
85        let transcript = crate::Transcript::from_stream(agent.run(Task::new("test task"))).await.unwrap();
86        let messages = transcript.events();
87
88        assert!(matches!(messages.first(), Some(AgentEvent::Message(MessageEvent::Text { .. }))));
89        assert!(matches!(messages.get(1), Some(AgentEvent::Turn(TurnEvent::Ended { .. }))));
90    }
91
92    #[tokio::test]
93    async fn fake_agent_with_tool_call_sends_tool_messages() {
94        let agent = FakeAgent::with_tool_call("bash", "success");
95        let transcript = crate::Transcript::from_stream(agent.run(Task::new("test task"))).await.unwrap();
96        let messages = transcript.events();
97
98        assert_eq!(messages.len(), 3);
99        assert!(matches!(messages.last(), Some(AgentEvent::Turn(TurnEvent::Ended { .. }))));
100    }
101
102    #[tokio::test]
103    async fn fake_agent_writes_file_in_workspace() {
104        let temp_dir = tempfile::tempdir().unwrap();
105        let agent = FakeAgent::writes_file("nested/hello.txt", "hello").with_workspace(temp_dir.path());
106        crate::Transcript::from_stream(agent.run(Task::new("test task"))).await.unwrap();
107        assert_eq!(std::fs::read_to_string(temp_dir.path().join("nested/hello.txt")).unwrap(), "hello");
108    }
109}
aether_evals/agents/fake_agent.rs

aether_evals/agents/
fake_agent.rs
