fix: change how we log resolve tester hints (#177)

* fix: change how we log resolve tester hints

* fix: add test for ResolveHint logging

Author: nicklasl

sdk-java/pom.xml

@@ -10,12 +10,6 @@
   <artifactId>sdk-java</artifactId>
 
   <dependencies>
-    <dependency>
-      <groupId>com.google.protobuf</groupId>
-      <artifactId>protobuf-java-util</artifactId>
-      <version>${protobuf.version}</version>
-      <scope>test</scope>
-    </dependency>
     <dependency>
       <groupId>io.grpc</groupId>
       <artifactId>grpc-protobuf</artifactId>
@@ -27,6 +21,11 @@
         </exclusion>
       </exclusions>
     </dependency>
+    <dependency>
+      <groupId>com.google.protobuf</groupId>
+      <artifactId>protobuf-java-util</artifactId>
+      <version>${protobuf.version}</version>
+    </dependency>
     <dependency>
       <groupId>dev.failsafe</groupId>
       <artifactId>failsafe</artifactId>
@@ -37,6 +36,12 @@
       <artifactId>proto-google-common-protos</artifactId>
       <version>${common.protos.version}</version>
     </dependency>
+    <dependency>
+      <groupId>ch.qos.logback</groupId>
+      <artifactId>logback-classic</artifactId>
+      <version>1.4.14</version>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
 
   <build>

sdk-java/src/main/java/com/spotify/confidence/Confidence.java

@@ -9,22 +9,24 @@
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Maps;
 import com.google.common.io.Closer;
+import com.google.protobuf.InvalidProtocolBufferException;
+import com.google.protobuf.util.JsonFormat;
 import com.spotify.confidence.ConfidenceUtils.FlagPath;
 import com.spotify.confidence.Exceptions.IllegalValuePath;
 import com.spotify.confidence.Exceptions.IllegalValueType;
 import com.spotify.confidence.Exceptions.IncompatibleValueType;
 import com.spotify.confidence.Exceptions.ValueNotFound;
 import com.spotify.confidence.shaded.flags.resolver.v1.ResolveFlagsResponse;
 import com.spotify.confidence.shaded.flags.resolver.v1.ResolvedFlag;
+import com.spotify.internal.v1.ResolveTesterLogging;
 import io.grpc.ManagedChannel;
 import io.grpc.ManagedChannelBuilder;
 import io.grpc.StatusRuntimeException;
 import java.io.Closeable;
 import java.io.IOException;
-import java.net.URLEncoder;
-import java.nio.charset.StandardCharsets;
 import java.time.Duration;
 import java.time.Instant;
+import java.util.Base64;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
@@ -41,6 +43,7 @@ public abstract class Confidence implements FlagEvaluator, EventSender, Closeabl
 
   protected Map<String, ConfidenceValue> context = Maps.newHashMap();
   private static final Logger log = org.slf4j.LoggerFactory.getLogger(Confidence.class);
+  private static final JsonFormat.Printer jsonPrinter = JsonFormat.printer();
 
   protected Confidence() {
     // Protected constructor to allow subclassing
@@ -137,15 +140,7 @@ public <T> FlagEvaluation<T> getEvaluation(String key, T defaultValue) {
       }
 
       final ResolvedFlag resolvedFlag = response.getResolvedFlags(0);
-      final String clientKey = client().clientSecret;
-      final String flag = resolvedFlag.getFlag();
-      final String context = URLEncoder.encode(getContext().toString(), StandardCharsets.UTF_8);
-      final String logMessage =
-          String.format(
-              "See resolves for '%s' in Confidence: "
-                  + "https://app.confidence.spotify.com/flags/resolver-test?client-key=%s&flag=flags/%s&context=%s",
-              flag, clientKey, flag, context);
-      log.debug(logMessage);
+      logResolveTesterHint(resolvedFlag);
       if (!requestFlagName.equals(resolvedFlag.getFlag())) {
         final String errorMessage =
             String.format(
@@ -201,6 +196,30 @@ public <T> FlagEvaluation<T> getEvaluation(String key, T defaultValue) {
     }
   }
 
+  @VisibleForTesting
+  public void logResolveTesterHint(ResolvedFlag resolvedFlag) {
+    final String clientKey = client().clientSecret;
+    final String flag = resolvedFlag.getFlag();
+    try {
+      final ResolveTesterLogging resolveTesterLogging =
+          ResolveTesterLogging.newBuilder()
+              .setClientKey(clientKey)
+              .setFlag(flag)
+              .setContext(getContext().toProto())
+              .build();
+      final String base64 =
+          Base64.getEncoder().encodeToString(jsonPrinter.print(resolveTesterLogging).getBytes());
+      final String logMessage =
+          String.format(
+              "Check your flag evaluation for '%s' by copy pasting the payload to the Resolve tester '%s'",
+              flag, base64);
+      log.debug(logMessage);
+    } catch (InvalidProtocolBufferException e) {
+      log.warn("Failed to produce correct resolve tester content", e);
+      // warn and ignore is enough
+    }
+  }
+
   CompletableFuture<ResolveFlagsResponse> resolveFlags(String flagName) {
     return client().resolveFlags(flagName, getContext());
   }

sdk-java/src/main/proto/confidence/internal.proto

@@ -0,0 +1,14 @@
+syntax = "proto3";
+
+import "google/protobuf/struct.proto";
+
+package confidence.internal.v1;
+option java_package = "com.spotify.internal.v1";
+option java_multiple_files = true;
+option java_outer_classname = "SdkLogging";
+
+message ResolveTesterLogging {
+    string client_key = 1;
+    string flag = 2;
+    google.protobuf.Value context = 3;
+}

sdk-java/src/test/java/com/spotify/confidence/ConfidenceTest.java

@@ -2,6 +2,10 @@
 
 import static org.junit.jupiter.api.Assertions.*;
 
+import ch.qos.logback.classic.Level;
+import ch.qos.logback.classic.Logger;
+import ch.qos.logback.classic.spi.ILoggingEvent;
+import ch.qos.logback.core.read.ListAppender;
 import com.google.protobuf.Value;
 import com.spotify.confidence.ConfidenceValue.Struct;
 import com.spotify.confidence.shaded.flags.resolver.v1.ResolveFlagsResponse;
@@ -15,18 +19,33 @@
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.CompletableFuture;
+import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.slf4j.LoggerFactory;
 
 final class ConfidenceTest {
   private final FakeEventSenderEngine fakeEngine = new FakeEventSenderEngine(new FakeClock());
   private final ResolverClientTestUtils.FakeFlagResolverClient fakeFlagResolverClient =
       new ResolverClientTestUtils.FakeFlagResolverClient();
   private static Confidence confidence;
+  private ListAppender<ILoggingEvent> listAppender;
+  private Logger confidenceLogger;
 
   @BeforeEach
   void beforeEach() {
     confidence = Confidence.create(fakeEngine, fakeFlagResolverClient, "clientKey");
+    confidenceLogger = (Logger) LoggerFactory.getLogger(Confidence.class);
+
+    listAppender = new ListAppender<>();
+    listAppender.start();
+    // Add the appender to the logger
+    confidenceLogger.addAppender(listAppender);
+  }
+
+  @AfterEach
+  void afterEach() {
+    confidenceLogger.detachAppender(listAppender);
   }
 
   @Test
@@ -259,6 +278,22 @@ void internalError() {
         evaluation.getErrorMessage().get().startsWith("Crashing while performing network call"));
   }
 
+  @Test
+  void shouldLogResolverHint() {
+    confidence
+        .withContext(Map.of("my_context_value", ConfidenceValue.of(42)))
+        .logResolveTesterHint(ResolvedFlag.newBuilder().setFlag("FlagName").build());
+    final List<ILoggingEvent> loggingEvents = listAppender.list;
+    assertTrue(loggingEvents.size() > 0, "No log message was captured.");
+    final ILoggingEvent lastLogEvent = loggingEvents.get(loggingEvents.size() - 1);
+    assertEquals(Level.DEBUG, lastLogEvent.getLevel()); // Or whatever level you expect
+    assertEquals(
+        "Check your flag evaluation for 'FlagName' by copy pasting the payload to the Resolve tester "
+            + "'ewogICJjbGllbnRLZXkiOiAiY2xpZW50S2V5IiwKICAiZmxhZyI6ICJGbGFnTmFtZSIsCiAgImN"
+            + "vbnRleHQiOiB7CiAgICAibXlfY29udGV4dF92YWx1ZSI6IDQyLjAKICB9Cn0='",
+        lastLogEvent.getFormattedMessage());
+  }
+
   public static class FailingFlagResolverClient implements FlagResolverClient {
 
     @Override