Enable tracing logging in factors tests

This gives more output when debugging test failures.

Signed-off-by: Lann Martin <[email protected]>

Author: lann

crates/factors-test/Cargo.toml

@@ -8,6 +8,7 @@ edition = { workspace = true }
 spin-app = { path = "../app" }
 spin-factors = { path = "../factors" }
 spin-loader = { path = "../loader" }
+spin-telemetry = { path = "../telemetry", features = ["testing"] }
 tempfile = { workspace = true }
 toml = { workspace = true }
 

crates/factors-test/src/lib.rs

@@ -22,6 +22,8 @@ impl<T: RuntimeFactors> TestEnvironment<T> {
     /// Creates a new test environment by initializing the given
     /// [`RuntimeFactors`].
     pub fn new(mut factors: T) -> Self {
+        spin_telemetry::testing::init_test_telemetry();
+
         let engine = Engine::new(Config::new().async_support(true))
             .expect("wasmtime engine failed to initialize");
         let mut linker = Linker::<T::InstanceState>::new(&engine);

crates/telemetry/Cargo.toml

@@ -18,4 +18,5 @@ tracing-opentelemetry = { version = "0.29", default-features = false, features =
 tracing-subscriber = { version = "0.3", default-features = false, features = ["smallvec", "fmt", "ansi", "std", "env-filter", "json", "registry"] }
 
 [features]
+testing = []
 tracing-log-compat = ["tracing-subscriber/tracing-log", "tracing-opentelemetry/tracing-log"]

crates/telemetry/src/lib.rs

@@ -15,6 +15,9 @@ pub mod metrics;
 mod propagation;
 mod traces;
 
+#[cfg(feature = "testing")]
+pub mod testing;
+
 pub use propagation::extract_trace_context;
 pub use propagation::inject_trace_context;
 

crates/telemetry/src/testing.rs

@@ -0,0 +1,9 @@
+/// Initializes telemetry integration for libtest environments.
+pub fn init_test_telemetry() {
+    static ONCE: std::sync::Once = std::sync::Once::new();
+    ONCE.call_once(|| {
+        if let Err(err) = tracing_subscriber::fmt().with_test_writer().try_init() {
+            eprintln!("init_test_telemetry failed to init global tracing_subscriber: {err:?}");
+        }
+    });
+}