Add tests for tracing appender (#1415)

opentelemetry-appender-tracing/Cargo.toml

@@ -24,3 +24,4 @@ opentelemetry-stdout = { path = "../opentelemetry-stdout", features = ["logs"] }
 [features]
 logs_level_enabled = ["opentelemetry/logs_level_enabled", "opentelemetry_sdk/logs_level_enabled"]
 default = ["logs_level_enabled"]
+testing = ["opentelemetry_sdk/testing"]

opentelemetry-appender-tracing/src/layer.rs

@@ -140,3 +140,145 @@ const fn severity_of_level(level: &Level) -> Severity {
         Level::ERROR => Severity::Error,
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::layer;
+    use opentelemetry::logs::Severity;
+    use opentelemetry::trace::TracerProvider as _;
+    use opentelemetry::trace::{TraceContextExt, TraceFlags, Tracer};
+    use opentelemetry::{logs::AnyValue, Key};
+    use opentelemetry_sdk::logs::LoggerProvider;
+    use opentelemetry_sdk::testing::logs::InMemoryLogsExporter;
+    use opentelemetry_sdk::trace::{config, Sampler, TracerProvider};
+    use tracing::error;
+    use tracing_subscriber::layer::SubscriberExt;
+
+    // cargo test --features=testing
+    #[test]
+    fn tracing_appender_standalone() {
+        // Arrange
+        let exporter: InMemoryLogsExporter = InMemoryLogsExporter::default();
+        let logger_provider = LoggerProvider::builder()
+            .with_simple_exporter(exporter.clone())
+            .build();
+
+        let layer = layer::OpenTelemetryTracingBridge::new(&logger_provider);
+        let subscriber = tracing_subscriber::registry().with(layer);
+
+        // avoiding setting tracing subscriber as global as that does not
+        // play well with unit tests.
+        let _guard = tracing::subscriber::set_default(subscriber);
+
+        // Act
+        error!(name: "my-event-name", target: "my-system", event_id = 20, user_name = "otel", user_email = "[email protected]");
+        logger_provider.force_flush();
+
+        // Assert TODO: move to helper methods
+        let exported_logs = exporter
+            .get_emitted_logs()
+            .expect("Logs are expected to be exported.");
+        assert_eq!(exported_logs.len(), 1);
+        let log = exported_logs
+            .get(0)
+            .expect("Atleast one log is expected to be present.");
+
+        // Validate common fields
+        assert_eq!(log.instrumentation.name, "opentelemetry-appender-tracing");
+        assert_eq!(log.record.severity_number, Some(Severity::Error));
+
+        // Validate trace context is none.
+        assert!(log.record.trace_context.is_none());
+
+        // Validate attributes
+        let attributes: Vec<(Key, AnyValue)> = log
+            .record
+            .attributes
+            .clone()
+            .expect("Attributes are expected");
+        assert_eq!(attributes.len(), 4);
+        assert!(attributes.contains(&(Key::new("name"), "my-event-name".into())));
+        assert!(attributes.contains(&(Key::new("event_id"), 20.into())));
+        assert!(attributes.contains(&(Key::new("user_name"), "otel".into())));
+        assert!(attributes.contains(&(Key::new("user_email"), "[email protected]".into())));
+    }
+
+    #[test]
+    fn tracing_appender_inside_tracing_context() {
+        // Arrange
+        let exporter: InMemoryLogsExporter = InMemoryLogsExporter::default();
+        let logger_provider = LoggerProvider::builder()
+            .with_simple_exporter(exporter.clone())
+            .build();
+
+        let layer = layer::OpenTelemetryTracingBridge::new(&logger_provider);
+        let subscriber = tracing_subscriber::registry().with(layer);
+
+        // avoiding setting tracing subscriber as global as that does not
+        // play well with unit tests.
+        let _guard = tracing::subscriber::set_default(subscriber);
+
+        // setup tracing as well.
+        let tracer_provider = TracerProvider::builder()
+            .with_config(config().with_sampler(Sampler::AlwaysOn))
+            .build();
+        let tracer = tracer_provider.tracer("test-tracer");
+
+        // Act
+        let (trace_id_expected, span_id_expected) = tracer.in_span("test-span", |cx| {
+            let trace_id = cx.span().span_context().trace_id();
+            let span_id = cx.span().span_context().span_id();
+
+            // logging is done inside span context.
+            error!(name: "my-event-name", target: "my-system", event_id = 20, user_name = "otel", user_email = "[email protected]");
+           (trace_id, span_id)
+        });
+
+        logger_provider.force_flush();
+
+        // Assert TODO: move to helper methods
+        let exported_logs = exporter
+            .get_emitted_logs()
+            .expect("Logs are expected to be exported.");
+        assert_eq!(exported_logs.len(), 1);
+        let log = exported_logs
+            .get(0)
+            .expect("Atleast one log is expected to be present.");
+
+        // validate common fields.
+        assert_eq!(log.instrumentation.name, "opentelemetry-appender-tracing");
+        assert_eq!(log.record.severity_number, Some(Severity::Error));
+
+        // validate trace context.
+        assert!(log.record.trace_context.is_some());
+        assert_eq!(
+            log.record.trace_context.as_ref().unwrap().trace_id,
+            trace_id_expected
+        );
+        assert_eq!(
+            log.record.trace_context.as_ref().unwrap().span_id,
+            span_id_expected
+        );
+        assert_eq!(
+            log.record
+                .trace_context
+                .as_ref()
+                .unwrap()
+                .trace_flags
+                .unwrap(),
+            TraceFlags::SAMPLED
+        );
+
+        // validate attributes.
+        let attributes: Vec<(Key, AnyValue)> = log
+            .record
+            .attributes
+            .clone()
+            .expect("Attributes are expected");
+        assert_eq!(attributes.len(), 4);
+        assert!(attributes.contains(&(Key::new("name"), "my-event-name".into())));
+        assert!(attributes.contains(&(Key::new("event_id"), 20.into())));
+        assert!(attributes.contains(&(Key::new("user_name"), "otel".into())));
+        assert!(attributes.contains(&(Key::new("user_email"), "[email protected]".into())));
+    }
+}

opentelemetry/src/logs/record.rs

@@ -75,7 +75,7 @@ impl From<&SpanContext> for TraceContext {
 }
 
 /// Value types for representing arbitrary values in a log record.
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub enum AnyValue {
     /// An integer value
     Int(i64),