# Embedded Test
[](https://crates.io/crates/embedded-test)
[](https://docs.rs/embedded-test)
The embedded-test library provides a test harness for embedded systems (riscv, arm and xtensa).
Use this library on the target together with [probe-rs](https://probe.rs/) on the host to run integration tests on your
embedded device.
[probe-rs](https://probe.rs/) together with embedded-test provide a (libtest compatible) test runner, which will:
1. Flash all the tests to the device in one go (via the `probe-rs run` command)
2. Request information about all tests from the device (via semihosting SYS_GET_CMDLINE)
3. In turn for each testcase:
- Reset the device
- Signal to the device (via semihosting SYS_GET_CMDLINE) which test to run
- Wait for the device to signal that the test completed successfully or with error (via semihosting SYS_EXIT)
4. Report the results
Since the test runner (`probe-rs run`) is libtest compatible (
using [libtest-mimic](https://crates.io/crates/libtest-mimic)), you can use intellij or vscode to run individual tests
with the click of a button.
## Features
* Runs each test case individually, and resets the device between each test case
* Supports an init function which will be called before each test case and can pass state to the test cases
* Supports async test and init functions (needs feature `embassy`)
* Support `#[should_panic]`, `#[ignore]` and `#[timeout(<seconds>)]` attributes for each test case
## Usage
Add the following to your `Cargo.toml`:
```toml
[dev-dependencies]
embedded-test = { version = "0.6.0" }
[[test]]
name = "example_test"
harness = false
```
Install the runner on your system:
```bash
cargo install probe-rs-tools
```
Setup probe-rs as the runner in your `.cargo/config.toml`. For example:
```toml
[target.thumbv7em-none-eabihf]
runner = "probe-rs run --chip STM32F767ZITx"
# `probe-rs run` will autodetect whether the elf to flash is a normal firmware or a test binary
```
Add the following to your `build.rs` file:
```rust
fn main() {
println!("cargo::rustc-link-arg-tests=-Tembedded-test.x");
}
```
Then you can run your tests with `cargo test --test example_test` or use the button in vscode/intellij.
Having trouble setting up? Checkout out
the [FAQ and common Errors](https://github.com/probe-rs/embedded-test/wiki/FAQ-and-common-Errors) Wiki page.
## Example Test (e.g. `tests/example_test.rs`)
Check the [example folder](https://github.com/probe-rs/embedded-test/tree/master/examples)
for a complete example project for stm32/esp32.
```rust
#![no_std]
#![no_main]
#[cfg(test)]
#[embedded_test::tests]
mod tests {
use stm32f7xx_hal::pac::Peripherals;
// An optional init function which is called before every test
// Asyncness is optional, so is the return value
#[init]
async fn init() -> Peripherals {
Peripherals::take().unwrap()
}
// Tests can be async (needs feature `embassy`)
// Tests can take the state returned by the init function (optional)
#[test]
async fn takes_state(_state: Peripherals) {
assert!(true)
}
// Tests can be conditionally enabled (with a cfg attribute)
#[test]
#[cfg(feature = "log")]
fn log() {
rtt_target::rtt_init_log!();
log::info!("Hello, log!");
assert!(true)
}
// Tests can be ignored with the #[ignore] attribute
#[test]
#[ignore]
fn it_works_ignored() {
assert!(false)
}
// Tests can fail with a custom error message by returning a Result
#[test]
fn it_fails_with_err() -> Result<(), &'static str> {
Err("It failed because ...")
}
// Tests can be annotated with #[should_panic] if they are expected to panic
#[test]
#[should_panic]
fn it_passes() {
assert!(false)
}
// Tests can be annotated with #[timeout(<secs>)] to change the default timeout of 60s
#[test]
#[timeout(10)]
fn it_timeouts() {
loop {} // should run into the 10s timeout
}
}
```
## Configuration features
| `panic-handler` | Yes | Defines a panic-handler which will invoke `semihosting::process::abort()` on panic |
| `defmt` | No | Prints testcase exit result to defmt. You'll need to setup your defmt `#[global_logger]` yourself (e.g. `#[embedded_test::tests(setup=rtt_target::rtt_init_defmt!())`) . |
| `log` | No | Prints testcase exit result to log. You'll need to setup your logging sink yourself (e.g. `#[embedded_test::tests(setup=rtt_target::rtt_init_log!())`) |
| `embassy` | No | Enables async test and init functions. Note: You need to enable at least one executor feature on the embassy-executor crate unless you are using the `external-executor` feature. |
| `external-executor` | No | Allows you to bring your own embassy executor which you need to pass to the `#[tests]` macro (e.g. `#[embedded_test::tests(executor = esp_hal::embassy::executor::thread::Executor::new())]`) |
| `xtensa-semihosting` | No | Enables semihosting for xtensa targets. |
Please also note the doc for
the [Attribute Macro embedded_test::tests](https://docs.rs/embedded-test/latest/embedded-test/attr.tests.html).
## License
Licensed under either of:
- [Apache License, Version 2.0](http://www.apache.org/licenses/LICENSE-2.0)
- [MIT license](http://opensource.org/licenses/MIT)
at your option.
### Contribution
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in
the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without
any additional terms or conditions.
