[bug] Can't test an app with sidecar. Getting "No such file or directory (os error 2)" #13767
Description
Describe the bug
I'm trying to test that my application does have access to sidecar executables and can run them, so I implemented a test for that. But somehow, I keep getting "No such file or directory (os error 2)" whenever I run the tests. If I run the application in dev mode it can access the executable, if I build and run it in production mode, it also has access to the executable, but in the tests it fails.
Reproduction
Create a tauri app.
Add the sidecar in src-tauri/bin. In my example, donkidunk_ffmpeg.
Add the required capabilities:
{
"identifier": "shell:allow-execute",
"allow": [
{
"name": "bin/donkidunk_ffmpeg",
"sidecar": true
}
]
}Add the externalBin property to tauri.conf.json
"externalBin": [
"./bin/donkidunk_ffmpeg"
]Add a test getting the sidecar and spawning a command:
fn create_app<R: tauri::Runtime>(builder: tauri::Builder<R>) -> tauri::App<R> {
let app = builder
.build(tauri::generate_context!())
.expect("error while building tauri application");
return app;
}
#[cfg(test)]
mod tests {
use std::process::Command;
use super::*;
use tauri_plugin_shell::ShellExt;
#[tokio::test]
async fn it_should_run_ffmpeg_command() -> Result<(), String> {
let builder = tauri::test::mock_builder().plugin(tauri_plugin_shell::init());
let app = create_app(builder);
let ffmpeg = app.shell().sidecar("donkidunk_ffmpeg").unwrap();
println!("Running ffmpeg command...");
let status = Command::from(ffmpeg)
.arg("-version")
.spawn()
.map_err(|e| e.to_string())?
.wait_with_output();
assert!(status.is_ok());
Ok(())
}
}Run the test with cargo test -- --no-capture:
running 1 test
Running ffmpeg command...
Error: "No such file or directory (os error 2)"
test tests::it_should_run_ffmpeg_command ... FAILED
failures:
failures:
tests::it_should_run_ffmpeg_command
test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.03s
Expected behavior
It should get the sidecard and run the command successfully. If I change the sidecar with a common command (like echo "Hello, World!") it works as expected.
Full tauri info output
[✔] Environment
- OS: Mac OS 13.7.5 x86_64 (X64)
✔ Xcode Command Line Tools: installed
✔ rustc: 1.88.0 (6b00bc388 2025-06-23)
✔ cargo: 1.88.0 (873a06493 2025-05-10)
✔ rustup: 1.28.2 (e4f3ad6f8 2025-04-28)
✔ Rust toolchain: stable-x86_64-apple-darwin (default)
- node: 20.11.1
- pnpm: 10.12.1
- npm: 10.6.0
[-] Packages
- tauri 🦀: 2.6.2
- tauri-build 🦀: 2.3.0
- wry 🦀: 0.52.1
- tao 🦀: 0.34.0
- @tauri-apps/api : 2.5.0 (outdated, latest: 2.6.0)
- @tauri-apps/cli : 2.5.0 (outdated, latest: 2.6.2)
[-] Plugins
- tauri-plugin-log 🦀: 2.6.0
- @tauri-apps/plugin-log : 2.4.0 (outdated, latest: 2.6.0)
- tauri-plugin-dialog 🦀: 2.3.0
- @tauri-apps/plugin-dialog : 2.2.2 (outdated, latest: 2.3.0)
- tauri-plugin-shell 🦀: 2.3.0
- @tauri-apps/plugin-shell : not installed!
- tauri-plugin-fs 🦀: 2.4.0
- @tauri-apps/plugin-fs : 2.3.0 (outdated, latest: 2.4.0)
- tauri-plugin-sql 🦀: 2.3.0
- @tauri-apps/plugin-sql : 2.2.0 (outdated, latest: 2.3.0)
- tauri-plugin-os 🦀: 2.3.0
- @tauri-apps/plugin-os : 2.2.1 (outdated, latest: 2.3.0)
- tauri-plugin-opener 🦀: 2.4.0
- @tauri-apps/plugin-opener : 2.2.7 (outdated, latest: 2.4.0)
[-] App
- build-type: bundle
- CSP: media-src 'self' asset: http://asset.localhost blob: data:
- frontendDist: ../build
- devUrl: http://localhost:1420/
- framework: Svelte
- bundler: Vite
Additional context
If instead of creating a shell with the sidecar I create a standard rust Command manually pointing to the ffmpeg executable, it also works well.
Edit
Ok I did a bit more testing. I included this code in the command that gets the sidecar both in runtime and in tests:
let ffmpeg = app.shell().sidecar("donkidunk_ffmpeg").unwrap();
let mut command = Command::from(ffmpeg);
println!("Running command: {:?}", command.get_program());
println!("Command dir: {:?}", command.get_current_dir());
println!("Command args: {:?}", command.get_args());
println!("Command envs: {:?}", command.get_envs());When I run the test this is the executable path: project\\path\\src-tauri\\target\\debug\\deps\\donkidunk_ffmpeg.exe, while in runtime this is the path: project\\path\\src-tauri\\target\\debug\\donkidunk_ffmpeg.exe
The first file doesn't exists, the second one does. Is there a bug with tauri copying files for tests? or guessing the sidecar path?