feat(data-pipeline-ffi): Add ffi bindings for session token

Author: VianneyRuhlmann

data-pipeline-ffi/src/trace_exporter.rs

@@ -66,6 +66,7 @@ pub struct TraceExporterConfig {
     output_format: TraceExporterOutputFormat,
     compute_stats: bool,
     telemetry_cfg: Option<TelemetryConfig>,
+    test_session_token: Option<String>,
 }
 
 #[no_mangle]
@@ -274,6 +275,23 @@ pub unsafe extern "C" fn ddog_trace_exporter_config_set_compute_stats(
     }
 }
 
+/// Sets test session token to be included in the headers request.
+#[no_mangle]
+pub unsafe extern "C" fn ddog_trace_exporter_config_set_test_session_token(
+    config: Option<&mut TraceExporterConfig>,
+    token: CharSlice,
+) -> Option<Box<ExporterError>> {
+    if let Option::Some(handle) = config {
+        handle.test_session_token = match sanitize_string(lang) {
+            Ok(s) => Some(s),
+            Err(e) => return Some(e),
+        };
+        None
+    } else {
+        gen_error!(ErrorCode::InvalidArgument)
+    }
+}
+
 /// Create a new TraceExporter instance.
 ///
 /// # Arguments
@@ -313,6 +331,10 @@ pub unsafe extern "C" fn ddog_trace_exporter_new(
             builder.enable_telemetry(Some(cfg.clone()));
         }
 
+        if let Some(token) = &config.test_session_token {
+            builder.set_test_session_token(token);
+        }
+
         match builder.build() {
             Ok(exporter) => {
                 out_handle.as_ptr().write(Box::new(exporter));
@@ -406,7 +428,8 @@ mod tests {
             assert_eq!(cfg.input_format, TraceExporterInputFormat::V04);
             assert_eq!(cfg.output_format, TraceExporterOutputFormat::V04);
             assert!(!cfg.compute_stats);
-            assert!(cfg.telemetry_cfg.is_none());
+            assert!(cfg.telemetry_cfg.is_none())
+            assert!(cfg.test_session_token.is_none());
 
             ddog_trace_exporter_config_free(cfg);
         }