[dynamic control] Add TraceSamplingValidatorTest test (#2621)

Author: jackshirazi

dynamic-control/src/test/java/io/opentelemetry/contrib/dynamic/policy/TraceSamplingValidatorTest.java

@@ -0,0 +1,128 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.contrib.dynamic.policy;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.within;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+
+class TraceSamplingValidatorTest {
+
+  private static final String TRACE_SAMPLING_POLICY_TYPE = "trace-sampling";
+  private static final String PROBABILITY_FIELD = "probability";
+  private static final String TRACE_SAMPLING_ALIAS = "trace-sampling.probability";
+
+  private final TraceSamplingValidator validator = new TraceSamplingValidator();
+
+  @Test
+  void testGetPolicyType() {
+    assertThat(validator.getPolicyType()).isEqualTo(TRACE_SAMPLING_POLICY_TYPE);
+  }
+
+  @Test
+  void testGetAlias() {
+    assertThat(validator.getAlias()).isEqualTo(TRACE_SAMPLING_ALIAS);
+  }
+
+  @Test
+  void testValidate_ValidJson() {
+    String json = jsonForProbability(0.5);
+    TelemetryPolicy policy = validator.validate(json);
+    assertThat(policy).isNotNull();
+    assertThat(policy.getType()).isEqualTo(TRACE_SAMPLING_POLICY_TYPE);
+    assertThat(policy.getSpec().get(PROBABILITY_FIELD).asDouble()).isCloseTo(0.5, within(1e-9));
+  }
+
+  @ParameterizedTest
+  @ValueSource(doubles = {0.0, 1.0})
+  void testValidate_ValidJson_BoundaryValues(double probability) {
+    String json = jsonForProbability(probability);
+    TelemetryPolicy policy = validator.validate(json);
+    assertThat(policy).isNotNull();
+    assertThat(policy.getType()).isEqualTo(TRACE_SAMPLING_POLICY_TYPE);
+    assertThat(policy.getSpec().get(PROBABILITY_FIELD).asDouble())
+        .isCloseTo(probability, within(1e-9));
+  }
+
+  @Test
+  void testValidate_InvalidJson_Malformed() {
+    String json = "{invalid-json";
+    assertThat(validator.validate(json)).isNull();
+  }
+
+  @Test
+  void testValidate_InvalidJson_MissingPolicyType() {
+    String json = "{\"other-policy\": {\"probability\": 0.5}}";
+    assertThat(validator.validate(json)).isNull();
+  }
+
+  @Test
+  void testValidate_InvalidJson_MissingProbability() {
+    String json = "{\"" + TRACE_SAMPLING_POLICY_TYPE + "\": {\"other-field\": 0.5}}";
+    assertThat(validator.validate(json)).isNull();
+  }
+
+  @Test
+  void testValidate_InvalidJson_ProbabilityNotNumber() {
+    String json =
+        "{\"" + TRACE_SAMPLING_POLICY_TYPE + "\": {\"" + PROBABILITY_FIELD + "\": \"high\"}}";
+    assertThat(validator.validate(json)).isNull();
+  }
+
+  @ParameterizedTest
+  @ValueSource(doubles = {-0.1, 1.1})
+  void testValidate_InvalidJson_ProbabilityOutOfRange(double probability) {
+    String json = jsonForProbability(probability);
+    assertThat(validator.validate(json)).isNull();
+  }
+
+  @Test
+  void testValidateAlias_Valid() {
+    TelemetryPolicy policy = validator.validateAlias(TRACE_SAMPLING_ALIAS, "0.5");
+    assertThat(policy).isNotNull();
+    assertThat(policy.getType()).isEqualTo(TRACE_SAMPLING_POLICY_TYPE);
+    assertThat(policy.getSpec().get(PROBABILITY_FIELD).asDouble()).isCloseTo(0.5, within(1e-9));
+  }
+
+  @ParameterizedTest
+  @ValueSource(strings = {"0.0", "1.0"})
+  void testValidateAlias_Valid_BoundaryValues(String probability) {
+    TelemetryPolicy policy = validator.validateAlias(TRACE_SAMPLING_ALIAS, probability);
+    assertThat(policy).isNotNull();
+    assertThat(policy.getType()).isEqualTo(TRACE_SAMPLING_POLICY_TYPE);
+    assertThat(policy.getSpec().get(PROBABILITY_FIELD).asDouble())
+        .isCloseTo(Double.parseDouble(probability), within(1e-9));
+  }
+
+  @Test
+  void testValidateAlias_InvalidKey() {
+    assertThat(validator.validateAlias("other.key", "0.5")).isNull();
+  }
+
+  @Test
+  void testValidateAlias_InvalidValue_NotNumber() {
+    assertThat(validator.validateAlias(TRACE_SAMPLING_ALIAS, "invalid")).isNull();
+  }
+
+  @ParameterizedTest
+  @ValueSource(strings = {"-0.1", "1.1"})
+  void testValidateAlias_InvalidValue_OutOfRange(String probability) {
+    assertThat(validator.validateAlias(TRACE_SAMPLING_ALIAS, probability)).isNull();
+  }
+
+  private static String jsonForProbability(double probability) {
+    return "{\""
+        + TRACE_SAMPLING_POLICY_TYPE
+        + "\": {\""
+        + PROBABILITY_FIELD
+        + "\": "
+        + probability
+        + "}}";
+  }
+}