Remove guava dependency. Ensure unused dependencies are removed from pom.xml

pom.xml

@@ -41,12 +41,6 @@
 
   <dependencies>
 
-    <dependency>
-      <groupId>com.google.guava</groupId>
-      <artifactId>guava</artifactId>
-      <version>30.1.1-jre</version>
-    </dependency>
-
     <dependency>
       <groupId>org.projectlombok</groupId>
       <artifactId>lombok</artifactId>
@@ -60,6 +54,7 @@
       <groupId>com.github.spotbugs</groupId>
       <artifactId>spotbugs</artifactId>
       <version>4.7.1</version>
+      <scope>compile</scope>
     </dependency>
 
     <dependency>
@@ -79,7 +74,7 @@
     <dependency>
       <groupId>uk.org.lidalia</groupId>
       <artifactId>slf4j-test</artifactId>
-      <version>1.1.0</version>
+      <version>1.2.0</version>
       <scope>test</scope>
     </dependency>
 
@@ -126,6 +121,30 @@
 
   <build>
     <plugins>
+      <plugin>
+        <artifactId>maven-dependency-plugin</artifactId>
+        <version>3.3.0</version>
+        <executions>
+          <execution>
+            <phase>verify</phase>
+            <goals>
+              <goal>analyze</goal>
+            </goals>
+          </execution>
+        </executions>
+        <configuration>
+          <failOnWarning>true</failOnWarning>
+          <ignoredUnusedDeclaredDependencies>
+            <ignoredUnusedDeclaredDependency>com.github.spotbugs:*</ignoredUnusedDeclaredDependency>
+            <ignoredUnusedDeclaredDependency>org.junit*</ignoredUnusedDeclaredDependency>
+          </ignoredUnusedDeclaredDependencies>
+          <ignoredDependencies>
+            <ignoredDependency>com.google.code.findbugs*</ignoredDependency>
+            <ignoredDependency>com.github.spotbugs*</ignoredDependency>
+            <ignoredDependency>uk.org.lidalia:lidalia-slf4j-ext:*</ignoredDependency>
+          </ignoredDependencies>
+        </configuration>
+      </plugin>
       <plugin>
         <artifactId>maven-compiler-plugin</artifactId>
         <version>3.8.1</version>

src/main/java/dev/openfeature/javasdk/FeatureProvider.java

@@ -1,7 +1,6 @@
 package dev.openfeature.javasdk;
 
-import com.google.common.collect.Lists;
-
+import java.util.ArrayList;
 import java.util.List;
 
 /**
@@ -11,7 +10,7 @@ public interface FeatureProvider {
     Metadata getMetadata();
 
     default List<Hook> getProviderHooks() {
-        return Lists.newArrayList();
+        return new ArrayList<>();
     }
 
     ProviderEvaluation<Boolean> getBooleanEvaluation(String key, Boolean defaultValue, EvaluationContext ctx,

src/main/java/dev/openfeature/javasdk/HookSupport.java

@@ -1,14 +1,11 @@
 package dev.openfeature.javasdk;
 
-import java.util.List;
-import java.util.Map;
-import java.util.Objects;
-import java.util.Optional;
+import java.util.*;
 import java.util.function.Consumer;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
 import java.util.stream.Stream;
 
-import com.google.common.collect.Lists;
-
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 
@@ -74,8 +71,13 @@ class HookSupport {
     private Stream<EvaluationContext> callBeforeHooks(FlagValueType flagValueType, HookContext hookCtx,
                                                       List<Hook> hooks, Map<String, Object> hints) {
         // These traverse backwards from normal.
-        return Lists
-                .reverse(hooks)
+        List<Hook> reversedHooks = IntStream
+                .range(0, hooks.size())
+                .map(i -> hooks.size() - 1 - i)
+                .mapToObj(hooks::get)
+                .collect(Collectors.toList());
+
+        return reversedHooks
                 .stream()
                 .filter(hook -> hook.supportsFlagValueType(flagValueType))
                 .map(hook -> hook.before(hookCtx, hints))

src/test/java/dev/openfeature/javasdk/HookSpecTest.java

@@ -2,8 +2,6 @@ package dev.openfeature.javasdk;
 
 import java.util.*;
 
-import com.google.common.collect.ImmutableMap;
-import com.google.common.collect.Lists;
 import dev.openfeature.javasdk.fixtures.HookFixtures;
 import lombok.SneakyThrows;
 import org.junit.jupiter.api.*;
@@ -177,7 +175,7 @@ public class HookSpecTest implements HookFixtures {
         OpenFeatureAPI api = OpenFeatureAPI.getInstance();
         api.setProvider(new NoOpProvider() {
             public List<Hook> getProviderHooks() {
-                return Lists.newArrayList(new BooleanHook() {
+                return Collections.singletonList(new BooleanHook() {
 
                     @Override
                     public Optional<EvaluationContext> before(HookContext<Boolean> ctx, Map<String, Object> hints) {
@@ -186,7 +184,8 @@ public class HookSpecTest implements HookFixtures {
                     }
 
                     @Override
-                    public void after(HookContext<Boolean> ctx, FlagEvaluationDetails<Boolean> details, Map<String, Object> hints) {
+                    public void after(HookContext<Boolean> ctx, FlagEvaluationDetails<Boolean> details, Map<String,
+                            Object> hints) {
                         evalOrder.add("provider after");
                     }
 
@@ -348,7 +347,9 @@ public class HookSpecTest implements HookFixtures {
             }
         };
 
-        Map<String, Object> hh = new HashMap<>(ImmutableMap.of(hintKey, "My hint value"));
+        Map<String, Object> hh = new HashMap<>();
+        hh.put(hintKey, "My hint value");
+        hh = Collections.unmodifiableMap(hh);
 
         client.getBooleanValue("key", false, new EvaluationContext(), FlagEvaluationOptions.builder()
                 .hook(mutatingHook)

src/test/java/dev/openfeature/javasdk/internal/ObjectUtilsTest.java

@@ -2,7 +2,6 @@ package dev.openfeature.javasdk.internal;
 
 import java.util.*;
 
-import com.google.common.collect.ImmutableMap;
 import org.junit.jupiter.api.*;
 
 import static dev.openfeature.javasdk.internal.ObjectUtils.defaultIfNull;
@@ -65,7 +64,9 @@ class ObjectUtilsTest {
         @Test
         @DisplayName("should return default map if given one is null")
         void shouldReturnDefaultMapIfGivenOneIsNull() {
-            Map<String, Object> defaultValue = ImmutableMap.of("key", "default");
+            HashMap<String, String> hm = new HashMap<>();
+            hm.put("key", "default");
+            Map<String, Object> defaultValue = Collections.unmodifiableMap(hm);
 
             Map<String, Object> actual = defaultIfNull(null, () -> defaultValue);
 
@@ -75,8 +76,13 @@ class ObjectUtilsTest {
         @Test
         @DisplayName("should return given map if not null")
         void shouldReturnGivenMapIfNotNull() {
-            Map<String, String> defaultValue = ImmutableMap.of("key", "default");
-            Map<String, String> expectedValue = ImmutableMap.of("key", "expected");
+            Map<String, String> dv = new HashMap<>();
+            dv.put("key", "default");
+            Map<String, String> defaultValue = Collections.unmodifiableMap(dv);
+
+            Map<String, String> ev = new HashMap<>();
+            ev.put("key", "expected");
+            Map<String, String> expectedValue = Collections.unmodifiableMap(ev);
 
             Map<String, String> actual = defaultIfNull(expectedValue, () -> defaultValue);