Fix test files and add missing Function imports for method lookups

Co-authored-by: trask <[email protected]>

Author: Copilot

instrumentation/reactor/reactor-3.1/javaagent/src/test/java/io/opentelemetry/javaagent/instrumentation/reactor/v3_1/ContextPropagationOperatorInstrumentationTest.java

@@ -19,6 +19,7 @@
 import java.lang.invoke.MethodHandles;
 import java.time.Duration;
 import java.util.function.Function;
+import java.util.function.UnaryOperator;
 import javax.annotation.Nullable;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.RegisterExtension;
@@ -194,7 +195,7 @@ void storeContextForcesItToBecomeCurrent() {
   }
 
   private static class StoreOpenTelemetryContext
-      implements Function<reactor.util.context.Context, reactor.util.context.Context> {
+      implements UnaryOperator<reactor.util.context.Context> {
 
     private final Span span;
 

instrumentation/reactor/reactor-3.1/library/src/main/java/io/opentelemetry/instrumentation/reactor/v3_1/ContextPropagationOperator.java

@@ -31,6 +31,7 @@
 import java.lang.invoke.MethodHandle;
 import java.lang.invoke.MethodHandles;
 import java.util.function.BiFunction;
+import java.util.function.Function;
 import java.util.function.UnaryOperator;
 import java.util.logging.Level;
 import java.util.logging.Logger;

instrumentation/reactor/reactor-3.1/library/src/test/java/io/opentelemetry/instrumentation/reactor/v3_1/ReactorCoreTest.java

@@ -25,6 +25,7 @@
 import java.time.Duration;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.Function;
+import java.util.function.UnaryOperator;
 import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
@@ -131,7 +132,7 @@ void fluxInNonBlockingPublisherAssembly() {
                 (Flux<Integer>)
                     FLUX_CONTEXT_WRITE_METHOD.invoke(
                         interim,
-                        (Function<reactor.util.context.Context, reactor.util.context.Context>)
+                        (UnaryOperator<reactor.util.context.Context>)
                             ctx -> {
                               Context parent =
                                   ContextPropagationOperator.getOpenTelemetryContext(
@@ -389,7 +390,7 @@ void doesNotOverrideInnerCurrentSpansWithThereIsOuterCurrent() {
             (Flux<Object>)
                 FLUX_CONTEXT_WRITE_METHOD.invoke(
                     interim,
-                    (Function<reactor.util.context.Context, reactor.util.context.Context>)
+                    (UnaryOperator<reactor.util.context.Context>)
                         context -> {
                           // subscribers that know that their subscription can happen
                           // ahead of time and in the 'wrong' context, has to clean up 'wrong'
@@ -565,7 +566,7 @@ private <T> Mono<T> monoSpan(Mono<T> mono, String spanName) {
       return (Mono<T>)
           MONO_CONTEXT_WRITE_METHOD.invoke(
               interim,
-              (Function<reactor.util.context.Context, reactor.util.context.Context>)
+              (UnaryOperator<reactor.util.context.Context>)
                   ctx -> {
                     Context parent =
                         ContextPropagationOperator.getOpenTelemetryContext(ctx, Context.current());

instrumentation/resources/library/src/test/java/io/opentelemetry/instrumentation/resources/internal/JarServiceNameResourceExtractorTest.java

@@ -12,8 +12,8 @@
 import io.opentelemetry.sdk.resources.Resource;
 import java.nio.file.Path;
 import java.nio.file.Paths;
-import java.util.function.Function;
 import java.util.function.Predicate;
+import java.util.function.UnaryOperator;
 import java.util.stream.Stream;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
@@ -29,7 +29,7 @@ class JarServiceNameResourceExtractorTest {
   @Test
   void extractResource_empty() {
     String[] processArgs = new String[0];
-    Function<String, String> getProperty = prop -> null;
+    UnaryOperator<String> getProperty = prop -> null;
     Predicate<Path> fileExists = JarServiceNameResourceExtractorTest::failPath;
     JarServiceNameResourceExtractor serviceNameProvider =
         getExtractor(processArgs, getProperty, fileExists);
@@ -40,7 +40,7 @@ void extractResource_empty() {
   }
 
   private static JarServiceNameResourceExtractor getExtractor(
-      String[] processArgs, Function<String, String> getProperty, Predicate<Path> fileExists) {
+      String[] processArgs, UnaryOperator<String> getProperty, Predicate<Path> fileExists) {
     return new JarServiceNameResourceExtractor(
         new MainJarPathFinder(() -> processArgs, getProperty, fileExists));
   }
@@ -100,7 +100,7 @@ static String[] getArgs(String jarName) {
   @ParameterizedTest
   @MethodSource("sunCommandLineArguments")
   void extractResource_sunCommandLine(String commandLine, Path jarPath) {
-    Function<String, String> getProperty =
+    UnaryOperator<String> getProperty =
         key -> "sun.java.command".equals(key) ? commandLine : null;
     Predicate<Path> fileExists = jarPath::equals;
 
@@ -116,7 +116,7 @@ void extractResource_sunCommandLine(String commandLine, Path jarPath) {
   // https://github.com/open-telemetry/opentelemetry-java-instrumentation/pull/7567
   @Test
   void extractResource_sunCommandLineProblematicArgs() {
-    Function<String, String> getProperty =
+    UnaryOperator<String> getProperty =
         key -> key.equals("sun.java.command") ? "one C:/two" : null;
     Predicate<Path> fileExists = path -> false;