Bug fix: ProfileFileSupplier aggregate files in order

Author: dave-fn

.changes/next-release/bugfix-AWSSDKforJavav2-6d1d0aa.json

@@ -0,0 +1,6 @@
+{
+    "category": "AWS SDK for Java v2", 
+    "contributor": "", 
+    "type": "bugfix", 
+    "description": "Keep precedence of options when passed to ProfileFileSupplier.aggregate"
+}

core/profiles/src/main/java/software/amazon/awssdk/profiles/ProfileFileSupplier.java

@@ -16,6 +16,8 @@
 package software.amazon.awssdk.profiles;
 
 import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.concurrent.ConcurrentHashMap;
@@ -124,29 +126,31 @@ static ProfileFileSupplier aggregate(ProfileFileSupplier... suppliers) {
             @Override
             public ProfileFile get() {
                 boolean refreshAggregate = false;
+                List<ProfileFile> nextValues = new ArrayList<>(suppliers.length);
                 for (ProfileFileSupplier supplier : suppliers) {
-                    if (didSuppliedValueChange(supplier)) {
+                    if (didSuppliedValueChange(supplier, nextValues)) {
                         refreshAggregate = true;
                     }
                 }
 
                 if (refreshAggregate) {
-                    refreshCurrentAggregate();
+                    refreshCurrentAggregate(nextValues);
                 }
 
                 return  currentAggregateProfileFile.get();
             }
 
-            private boolean didSuppliedValueChange(Supplier<ProfileFile> supplier) {
+            private boolean didSuppliedValueChange(Supplier<ProfileFile> supplier, List<ProfileFile> nextValues) {
                 ProfileFile next = supplier.get();
+                nextValues.add(next);
                 ProfileFile current = currentValuesBySupplier.put(supplier, next);
 
                 return !Objects.equals(next, current);
             }
 
-            private void refreshCurrentAggregate() {
+            private void refreshCurrentAggregate(List<ProfileFile> nextValues) {
                 ProfileFile.Aggregator aggregator = ProfileFile.aggregator();
-                currentValuesBySupplier.values().forEach(aggregator::addFile);
+                nextValues.forEach(aggregator::addFile);
                 ProfileFile current = currentAggregateProfileFile.get();
                 ProfileFile next = aggregator.build();
                 if (!Objects.equals(current, next)) {

core/profiles/src/test/java/software/amazon/awssdk/profiles/ProfileFileSupplierTest.java

@@ -410,6 +410,56 @@ void aggregate_supplierReturnsSameInstanceMultipleTimesAggregatingProfileFileSup
         assertThat(suppliedProfileFiles).isEqualTo(distinctAggregateProfileFiles);
     }
 
+    @Test
+    void aggregate_duplicateOptionsGivenFixedProfileFirst_preservesPrecedence() {
+        ProfileFile configFile1 = configFile("profile default", Pair.of("aws_access_key_id", "config-key"));
+        Path credentialsFilePath = generateTestCredentialsFile("defaultAccessKey", "defaultSecretAccessKey");
+
+        ProfileFileSupplier supplier = ProfileFileSupplier.aggregate(
+            ProfileFileSupplier.fixedProfileFile(configFile1),
+            ProfileFileSupplier.reloadWhenModified(credentialsFilePath, ProfileFile.Type.CREDENTIALS));
+
+        ProfileFile profileFile = supplier.get();
+        String accessKeyId = profileFile.profile("default").get().property("aws_access_key_id").get();
+
+        assertThat(accessKeyId).isEqualTo("config-key");
+
+        generateTestCredentialsFile("defaultAccessKey2", "defaultSecretAccessKey2");
+
+        profileFile = supplier.get();
+        accessKeyId = profileFile.profile("default").get().property("aws_access_key_id").get();
+
+        assertThat(accessKeyId).isEqualTo("config-key");
+    }
+
+    @Test
+    void aggregate_duplicateOptionsGivenReloadingProfileFirst_preservesPrecedence() {
+        AdjustableClock clock = new AdjustableClock();
+
+        ProfileFile configFile1 = configFile("profile default", Pair.of("aws_access_key_id", "config-key"));
+        Path credentialsFilePath = generateTestCredentialsFile("defaultAccessKey", "defaultSecretAccessKey");
+
+        ProfileFileSupplier supplier = ProfileFileSupplier.aggregate(
+            builderWithClock(clock)
+                .reloadWhenModified(credentialsFilePath, ProfileFile.Type.CREDENTIALS)
+                .build(),
+            ProfileFileSupplier.fixedProfileFile(configFile1));
+
+        ProfileFile profileFile = supplier.get();
+        String accessKeyId = profileFile.profile("default").get().property("aws_access_key_id").get();
+
+        assertThat(accessKeyId).isEqualTo("defaultAccessKey");
+
+        generateTestCredentialsFile("defaultAccessKey2", "defaultSecretAccessKey2");
+
+        clock.tickForward(Duration.ofMillis(1_000));
+
+        profileFile = supplier.get();
+        accessKeyId = profileFile.profile("default").get().property("aws_access_key_id").get();
+
+        assertThat(accessKeyId).isEqualTo("defaultAccessKey2");
+    }
+
     @Test
     void fixedProfileFile_nullProfileFile_returnsNonNullSupplier() {
         ProfileFile file = null;