chore: add additional unit tests to increase test coverage

src/test/java/dev/openfeature/sdk/BooleanHookTest.java

@@ -0,0 +1,31 @@
+package dev.openfeature.sdk;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import dev.openfeature.sdk.fixtures.HookFixtures;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+class BooleanHookTest implements HookFixtures {
+
+    private Hook<Boolean> hook;
+
+    @BeforeEach
+    void setupTest() {
+        hook = mockBooleanHook();
+    }
+
+    @Test
+    void verifyFlagValueTypeIsSupportedByHook() {
+        boolean hookSupported = hook.supportsFlagValueType(FlagValueType.BOOLEAN);
+
+        assertThat(hookSupported).isTrue();
+    }
+
+    @Test
+    void verifyFlagValueTypeIsNotSupportedByHook() {
+        boolean hookSupported = hook.supportsFlagValueType(FlagValueType.INTEGER);
+
+        assertThat(hookSupported).isFalse();
+    }
+}

src/test/java/dev/openfeature/sdk/DoubleHookTest.java

@@ -0,0 +1,31 @@
+package dev.openfeature.sdk;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import dev.openfeature.sdk.fixtures.HookFixtures;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+class DoubleHookTest implements HookFixtures {
+
+    private Hook<Double> hook;
+
+    @BeforeEach
+    void setupTest() {
+        hook = mockDoubleHook();
+    }
+
+    @Test
+    void verifyFlagValueTypeIsSupportedByHook() {
+        boolean hookSupported = hook.supportsFlagValueType(FlagValueType.DOUBLE);
+
+        assertThat(hookSupported).isTrue();
+    }
+
+    @Test
+    void verifyFlagValueTypeIsNotSupportedByHook() {
+        boolean hookSupported = hook.supportsFlagValueType(FlagValueType.STRING);
+
+        assertThat(hookSupported).isFalse();
+    }
+}

src/test/java/dev/openfeature/sdk/ImmutableContextTest.java

@@ -135,6 +135,19 @@ void mergeShouldRetainItsSubkeysWhenOverridingContextHasNoTargetingKey() {
         assertArrayEquals(new Object[] {"key1_1"}, value.keySet().toArray());
     }
 
+    @DisplayName("Merge should obtain keys from the overriding context when the existing context is empty")
+    @Test
+    void mergeShouldObtainKeysFromOverridingContextWhenExistingContextIsEmpty() {
+        HashMap<String, Value> attributes = new HashMap<>();
+        attributes.put("key1", new Value("val1"));
+        attributes.put("key2", new Value("val2"));
+
+        EvaluationContext ctx = new ImmutableContext();
+        EvaluationContext overriding = new ImmutableContext(attributes);
+        EvaluationContext merge = ctx.merge(overriding);
+        assertEquals(new java.util.HashSet<>(java.util.Arrays.asList("key1", "key2")), merge.keySet());
+    }
+
     @DisplayName("Two different MutableContext objects with the different contents are not considered equal")
     @Test
     void unequalImmutableContextsAreNotEqual() {

src/test/java/dev/openfeature/sdk/IntegerHookTest.java

@@ -0,0 +1,31 @@
+package dev.openfeature.sdk;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import dev.openfeature.sdk.fixtures.HookFixtures;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+class IntegerHookTest implements HookFixtures {
+
+    private Hook<Integer> hook;
+
+    @BeforeEach
+    void setupTest() {
+        hook = mockIntegerHook();
+    }
+
+    @Test
+    void verifyFlagValueTypeIsSupportedByHook() {
+        boolean hookSupported = hook.supportsFlagValueType(FlagValueType.INTEGER);
+
+        assertThat(hookSupported).isTrue();
+    }
+
+    @Test
+    void verifyFlagValueTypeIsNotSupportedByHook() {
+        boolean hookSupported = hook.supportsFlagValueType(FlagValueType.STRING);
+
+        assertThat(hookSupported).isFalse();
+    }
+}

src/test/java/dev/openfeature/sdk/ObjectHookTest.java

@@ -0,0 +1,31 @@
+package dev.openfeature.sdk;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import dev.openfeature.sdk.fixtures.HookFixtures;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+class ObjectHookTest implements HookFixtures {
+
+    private Hook<Object> hook;
+
+    @BeforeEach
+    void setupTest() {
+        hook = mockObjectHook();
+    }
+
+    @Test
+    void verifyFlagValueTypeIsSupportedByHook() {
+        boolean hookSupported = hook.supportsFlagValueType(FlagValueType.OBJECT);
+
+        assertThat(hookSupported).isTrue();
+    }
+
+    @Test
+    void verifyFlagValueTypeIsNotSupportedByHook() {
+        boolean hookSupported = hook.supportsFlagValueType(FlagValueType.INTEGER);
+
+        assertThat(hookSupported).isFalse();
+    }
+}

src/test/java/dev/openfeature/sdk/StringHookTest.java

@@ -0,0 +1,31 @@
+package dev.openfeature.sdk;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import dev.openfeature.sdk.fixtures.HookFixtures;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+class StringHookTest implements HookFixtures {
+
+    private Hook<String> hook;
+
+    @BeforeEach
+    void setupTest() {
+        hook = mockStringHook();
+    }
+
+    @Test
+    void verifyFlagValueTypeIsSupportedByHook() {
+        boolean hookSupported = hook.supportsFlagValueType(FlagValueType.STRING);
+
+        assertThat(hookSupported).isTrue();
+    }
+
+    @Test
+    void verifyFlagValueTypeIsNotSupportedByHook() {
+        boolean hookSupported = hook.supportsFlagValueType(FlagValueType.INTEGER);
+
+        assertThat(hookSupported).isFalse();
+    }
+}

src/test/java/dev/openfeature/sdk/fixtures/HookFixtures.java

@@ -6,6 +6,7 @@
 import dev.openfeature.sdk.DoubleHook;
 import dev.openfeature.sdk.Hook;
 import dev.openfeature.sdk.IntegerHook;
+import dev.openfeature.sdk.ObjectHook;
 import dev.openfeature.sdk.StringHook;
 
 public interface HookFixtures {
@@ -26,6 +27,10 @@ default Hook<Double> mockDoubleHook() {
         return spy(DoubleHook.class);
     }
 
+    default Hook<Object> mockObjectHook() {
+        return spy(ObjectHook.class);
+    }
+
     default Hook<?> mockGenericHook() {
         return spy(Hook.class);
     }