EnvironmentGetter.keys() normalizes values

Author: jack-berg

api/incubator/src/main/java/io/opentelemetry/api/incubator/propagation/EnvironmentGetter.java

@@ -8,6 +8,7 @@
 import io.opentelemetry.context.propagation.TextMapGetter;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.List;
 import java.util.Map;
 import javax.annotation.Nullable;
 
@@ -56,7 +57,11 @@ public Iterable<String> keys(Map<String, String> carrier) {
     if (carrier == null) {
       return Collections.emptyList();
     }
-    return new ArrayList<>(carrier.keySet());
+    List<String> result = new ArrayList<>(carrier.size());
+    for (String key : carrier.keySet()) {
+      result.add(EnvironmentSetter.normalizeKey(key));
+    }
+    return Collections.unmodifiableList(result);
   }
 
   @Nullable

api/incubator/src/test/java/io/opentelemetry/api/incubator/propagation/EnvironmentGetterTest.java

@@ -29,7 +29,7 @@ void get() {
   }
 
   @Test
-  void get_sanitization() {
+  void get_normalization() {
     Map<String, String> carrier = new HashMap<>();
     carrier.put("OTEL_TRACE_ID", "val1");
     carrier.put("OTEL_BAGGAGE_KEY", "val2");
@@ -45,12 +45,13 @@ void get_null() {
   }
 
   @Test
-  void keys() {
+  void keys_valuesAreNormalized() {
     Map<String, String> carrier = new HashMap<>();
-    carrier.put("K1", "V1");
-    carrier.put("K2", "V2");
+    carrier.put("otel.trace.id", "V1");
+    carrier.put("otel-baggage-key", "V2");
 
-    assertThat(EnvironmentGetter.getInstance().keys(carrier)).containsExactlyInAnyOrder("K1", "K2");
+    assertThat(EnvironmentGetter.getInstance().keys(carrier))
+        .containsExactlyInAnyOrder("OTEL_TRACE_ID", "OTEL_BAGGAGE_KEY");
     assertThat(EnvironmentGetter.getInstance().keys(null)).isEmpty();
   }