FFI lib load integration test

Author: ladvoc

Cargo.lock

@@ -45,6 +45,7 @@ prost-build = "0.14.1"
 webrtc-sys-build = { workspace = true }
 
 [dev-dependencies]
+libloading = "0.8.9"
 livekit-api = { workspace = true }
 
 [lib]

livekit-ffi/Cargo.toml

@@ -12,7 +12,10 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use std::{env, path::Path};
+use std::{
+    env,
+    path::{Path, PathBuf},
+};
 
 const PROTO_SRC_DIR: &str = "protocol";
 
@@ -23,6 +26,7 @@ fn main() {
     download_webrtc();
     copy_webrtc_license();
     configure_linker();
+    get_lib_path();
     generate_protobuf();
 }
 
@@ -61,6 +65,30 @@ fn configure_linker() {
     }
 }
 
+/// Get the path of the built library in the target directory, used for integration testing.
+fn get_lib_path() {
+    let out_dir = PathBuf::from(std::env::var("OUT_DIR").unwrap());
+    let target_dir = out_dir.ancestors().nth(4).expect("Failed to find target directory");
+
+    let build_profile = env::var("PROFILE").unwrap();
+    let output_dir = target_dir.join(build_profile);
+
+    let target_os = env::var("CARGO_CFG_TARGET_OS").unwrap();
+    let lib_extension = match target_os.as_str() {
+        "windows" => "dll",
+        "linux" | "android" => "so",
+        "macos" => "dylib",
+        "ios" => "a",
+        _ => {
+            panic!("Unsupported target, {}", target_os);
+        }
+    };
+    let crate_name = env::var("CARGO_PKG_NAME").unwrap();
+    let lib_name = format!("lib{}.{}", crate_name.replace("-", "_"), lib_extension);
+    let lib_path = output_dir.join(lib_name);
+    println!("cargo::rustc-env=FFI_LIB_PATH={}", lib_path.display());
+}
+
 fn generate_protobuf() {
     let paths: Vec<_> = std::fs::read_dir(PROTO_SRC_DIR)
         .expect("Failed to read protobuf source directory")

livekit-ffi/build.rs

@@ -272,4 +272,4 @@ impl FfiServer {
         });
         handle
     }
-}
+}

livekit-ffi/src/server/mod.rs

@@ -0,0 +1,39 @@
+use libloading::{Library, Symbol};
+use std::{path::Path, process::Command};
+
+const FFI_LIB_PATH: &str = env!("FFI_LIB_PATH"); // Set by build.rs
+
+const EXPECTED_SYMBOLS: &[&str] = &[
+    "livekit_ffi_initialize",
+    "livekit_ffi_request",
+    "livekit_ffi_drop_handle",
+    "livekit_ffi_dispose",
+];
+
+#[test]
+fn lib_load_test() {
+    println!("Library path: {}", FFI_LIB_PATH);
+    build_lib_if_required();
+    unsafe {
+        let lib = Library::new(FFI_LIB_PATH).expect("Unable to load library");
+        for symbol in EXPECTED_SYMBOLS {
+            let _loaded_symbol: Symbol<unsafe extern "C" fn() -> u32> =
+                lib.get(symbol.as_bytes()).expect(&format!("Missing symbol: {}", symbol));
+        }
+    }
+}
+
+fn build_lib_if_required() {
+    let path = Path::new(FFI_LIB_PATH);
+    if !path.try_exists().unwrap() {
+        println!("Library not found, building…");
+        let status = Command::new("cargo")
+            .args(&["build", "--lib"])
+            .status()
+            .expect("Failed to run cargo build for test");
+
+        if !status.success() || !path.try_exists().unwrap() {
+            panic!("Failed to build lib to run test");
+        }
+    }
+}