bt_test_harness/
low_energy_central.rs

1// Copyright 2022 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5use anyhow::{Context as _, Error};
6use fidl_fuchsia_bluetooth_le::{CentralEvent, CentralMarker, CentralProxy};
7use fidl_fuchsia_hardware_bluetooth::EmulatorProxy;
8use fuchsia_bluetooth::expectation::asynchronous::{
9    expectable, Expectable, ExpectableExt, ExpectableState,
10};
11use fuchsia_bluetooth::types::le::RemoteDevice;
12use futures::future::BoxFuture;
13use futures::{FutureExt, TryStreamExt};
14use std::ops::{Deref, DerefMut};
15use std::sync::Arc;
16use test_harness::{SharedState, TestHarness, SHARED_STATE_TEST_COMPONENT_INDEX};
17
18use crate::core_realm::{CoreRealm, SHARED_STATE_INDEX};
19use crate::host_watcher::ActivatedFakeHost;
20
21#[derive(PartialEq, Debug, Clone, Copy)]
22pub enum ScanStateChange {
23    ScanEnabled,
24    ScanDisabled,
25}
26
27/// A snapshot of the current LowEnergy Central State
28#[derive(Clone, Default)]
29pub struct CentralState {
30    /// Observed scan state changes.
31    pub scan_state_changes: Vec<ScanStateChange>,
32
33    /// Discovered devices.
34    pub remote_devices: Vec<RemoteDevice>,
35}
36
37/// Auxilliary data for the CentralHarness
38pub struct Aux {
39    pub central: CentralProxy,
40    emulator: EmulatorProxy,
41}
42
43impl AsRef<EmulatorProxy> for Aux {
44    fn as_ref(&self) -> &EmulatorProxy {
45        &self.emulator
46    }
47}
48
49#[derive(Clone)]
50pub struct CentralHarness(Expectable<CentralState, Aux>);
51
52impl Deref for CentralHarness {
53    type Target = Expectable<CentralState, Aux>;
54
55    fn deref(&self) -> &Self::Target {
56        &self.0
57    }
58}
59
60impl DerefMut for CentralHarness {
61    fn deref_mut(&mut self) -> &mut Self::Target {
62        &mut self.0
63    }
64}
65
66impl TestHarness for CentralHarness {
67    type Env = (ActivatedFakeHost, Arc<CoreRealm>);
68    type Runner = BoxFuture<'static, Result<(), Error>>;
69
70    fn init(
71        shared_state: &Arc<SharedState>,
72    ) -> BoxFuture<'static, Result<(Self, Self::Env, Self::Runner), Error>> {
73        let shared_state = shared_state.clone();
74        async move {
75            let test_component: Arc<String> = shared_state
76                .get(SHARED_STATE_TEST_COMPONENT_INDEX)
77                .expect("SharedState must have TEST-COMPONENT")?;
78            let inserter = move || CoreRealm::create(test_component.to_string());
79            let realm = shared_state.get_or_insert_with(SHARED_STATE_INDEX, inserter).await?;
80            let fake_host = ActivatedFakeHost::new(realm.clone()).await?;
81            let central = realm
82                .instance()
83                .connect_to_protocol_at_exposed_dir::<CentralMarker>()
84                .context("Failed to connect to BLE Central service")?;
85
86            let harness = CentralHarness(expectable(
87                Default::default(),
88                Aux { central, emulator: fake_host.emulator().clone() },
89            ));
90            let run_central = handle_central_events(harness.clone()).boxed();
91            Ok((harness, (fake_host, realm), run_central))
92        }
93        .boxed()
94    }
95
96    fn terminate((emulator, realm): Self::Env) -> BoxFuture<'static, Result<(), Error>> {
97        // The realm must be kept alive in order for emulator.release() to work properly.
98        async move {
99            let _realm = realm;
100            emulator.release().await
101        }
102        .boxed()
103    }
104}
105
106async fn handle_central_events(harness: CentralHarness) -> Result<(), Error> {
107    let mut events = harness.aux().central.take_event_stream();
108
109    while let Some(e) = events.try_next().await? {
110        match e {
111            CentralEvent::OnDeviceDiscovered { device } => {
112                harness.write_state().remote_devices.push(device.try_into()?);
113                harness.notify_state_changed();
114            }
115            CentralEvent::OnScanStateChanged { scanning } => {
116                let change = if scanning {
117                    ScanStateChange::ScanEnabled
118                } else {
119                    ScanStateChange::ScanDisabled
120                };
121                harness.write_state().scan_state_changes.push(change);
122                harness.notify_state_changed();
123            }
124            CentralEvent::OnPeripheralDisconnected { identifier: _ } => {}
125        };
126    }
127    Ok(())
128}
bt_test_harness/low_energy_central.rs

bt_test_harness/
low_energy_central.rs
