test: add tests for the index API

Signed-off-by: hi-rustin <[email protected]>

Author: 0xPoe

tracing/tests/collector.rs

@@ -27,7 +27,20 @@ fn event_macros_dont_infinite_loop() {
         }
 
         fn enabled(&self, meta: &Metadata<'_>) -> bool {
-            assert!(meta.fields().iter().any(|f| f.name() == "foo"));
+            assert_eq!(
+                meta.fields()
+                    .iter()
+                    .find(|f| f.name() == "foo")
+                    .map(|f| f.index()),
+                Some(0)
+            );
+            assert_eq!(
+                meta.fields()
+                    .iter()
+                    .find(|f| f.name() == "bar")
+                    .map(|f| f.index()),
+                Some(1)
+            );
             tracing::event!(Level::TRACE, bar = false);
             true
         }
@@ -41,7 +54,24 @@ fn event_macros_dont_infinite_loop() {
         fn record_follows_from(&self, _: &Id, _: &Id) {}
 
         fn event(&self, event: &Event<'_>) {
-            assert!(event.metadata().fields().iter().any(|f| f.name() == "foo"));
+            assert_eq!(
+                event
+                    .metadata()
+                    .fields()
+                    .iter()
+                    .find(|f| f.name() == "foo")
+                    .map(|f| f.index()),
+                Some(0)
+            );
+            assert_eq!(
+                event
+                    .metadata()
+                    .fields()
+                    .iter()
+                    .find(|f| f.name() == "bar")
+                    .map(|f| f.index()),
+                Some(1)
+            );
             tracing::event!(Level::TRACE, baz = false);
         }
 
@@ -55,7 +85,7 @@ fn event_macros_dont_infinite_loop() {
     }
 
     with_default(TestCollector, || {
-        tracing::event!(Level::TRACE, foo = false);
+        tracing::event!(Level::TRACE, foo = false, bar = false);
     })
 }