How to use org.sonar.server.qualitygate

private static void checkOperator(MetricDto metric, String operator, List<String> errors) {
 check(
  Condition.Operator.isValid(operator) && isAllowedOperator(operator, metric),
  errors,
  "Operator %s is not allowed for this metric.", operator
 );
}

public EvaluatedQualityGate build() {
 return new EvaluatedQualityGate(
  this.qualityGate,
  this.status,
  checkEvaluatedConditions(qualityGate, evaluatedConditions),
  ignoredConditionsOnSmallChangeset);
}

@Override
public String toString() {
 return "Condition{" +
  "metricKey='" + metricKey + '\'' +
  ", operator=" + operator +
  ", errorThreshold=" + toString(errorThreshold) +
  '}';
}

@Override
public EvaluatedQualityGate evaluate(QualityGate gate, Measures measures) {
 EvaluatedQualityGate.Builder result = EvaluatedQualityGate.newBuilder()
  .setQualityGate(gate);
 boolean isSmallChangeset = isSmallChangeset(measures);
 gate.getConditions().forEach(condition -> {
  String metricKey = condition.getMetricKey();
  EvaluatedCondition evaluation = ConditionEvaluator.evaluate(condition, measures);
  if (isSmallChangeset && evaluation.getStatus() != EvaluationStatus.OK && METRICS_TO_IGNORE_ON_SMALL_CHANGESETS.contains(metricKey)) {
   result.addCondition(new EvaluatedCondition(evaluation.getCondition(), EvaluationStatus.OK, evaluation.getValue().orElse(null)));
   result.setIgnoredConditionsOnSmallChangeset(true);
  } else {
   result.addCondition(evaluation);
  }
 });
 result.setStatus(overallStatusOf(result.getEvaluatedConditions()));
 return result.build();
}

 private static JsonObject toJson(EvaluatedCondition evaluatedCondition) {
  Condition condition = evaluatedCondition.getCondition();

  JsonObject result = new JsonObject();
  result.addProperty("metric", condition.getMetricKey());
  result.addProperty("op", condition.getOperator().getDbValue());
  if (condition.isOnLeakPeriod()) {
   result.addProperty("period", 1);
  }
  result.addProperty("error", condition.getErrorThreshold());
  evaluatedCondition.getValue().ifPresent(v -> result.addProperty("actual", v));
  result.addProperty(FIELD_LEVEL, evaluatedCondition.getStatus().name());
  return result;
 }
}

@Override
public EvaluatedQualityGate evaluate(QualityGate gate, Measures measures) {
 checkState(this.measures == null);
 this.measures = measures;
 EvaluatedQualityGate.Builder builder = EvaluatedQualityGate.newBuilder().setQualityGate(gate).setStatus(Metric.Level.OK);
 for (Condition condition : gate.getConditions()) {
  builder.addCondition(condition, EvaluatedCondition.EvaluationStatus.OK, "bar");
 }
 return builder.build();
}

private void test(@Nullable QualityGateEvaluator.Measure measure, Condition.Operator operator, String errorThreshold, EvaluatedCondition.EvaluationStatus expectedStatus, @Nullable String expectedValue) {
 Condition condition = new Condition("foo", operator, errorThreshold);
 EvaluatedCondition result = ConditionEvaluator.evaluate(condition, new FakeMeasures(measure));
 assertThat(result.getStatus()).isEqualTo(expectedStatus);
 if (expectedValue == null) {
  assertThat(result.getValue()).isNotPresent();
 } else {
  assertThat(result.getValue()).hasValue(expectedValue);
 }
}

/**
 * Evaluates the condition for the specified measure
 */
static EvaluatedCondition evaluate(Condition condition, QualityGateEvaluator.Measures measures) {
 Optional<QualityGateEvaluator.Measure> measure = measures.get(condition.getMetricKey());
 if (!measure.isPresent()) {
  return new EvaluatedCondition(condition, EvaluationStatus.OK, null);
 }
 Optional<Comparable> value = getMeasureValue(condition, measure.get());
 if (!value.isPresent()) {
  return new EvaluatedCondition(condition, EvaluationStatus.OK, null);
 }
 ValueType type = measure.get().getType();
 return evaluateCondition(condition, type, value.get())
  .orElseGet(() -> new EvaluatedCondition(condition, EvaluationStatus.OK, value.get().toString()));
}

@Test
public void addCondition_fails_with_NPE_if_status_is_null() {
 expectedException.expect(NullPointerException.class);
 expectedException.expectMessage("status can't be null");
 builder.addCondition(new Condition("metric_key", Condition.Operator.LESS_THAN, "2"), null, "a_value");
}

private static Optional<Comparable> getMeasureValue(Condition condition, QualityGateEvaluator.Measure measure) {
 if (condition.isOnLeakPeriod()) {
  return Optional.ofNullable(getLeakValue(measure));
 }
 return Optional.ofNullable(getValue(measure));
}

@Test
public void LESS_THAN_int() {
 test(new FakeMeasure(10), Condition.Operator.LESS_THAN, "9", EvaluatedCondition.EvaluationStatus.OK, "10");
 test(new FakeMeasure(10), Condition.Operator.LESS_THAN, "10", EvaluatedCondition.EvaluationStatus.OK, "10");
 test(new FakeMeasure(10), Condition.Operator.LESS_THAN, "11", EvaluatedCondition.EvaluationStatus.ERROR, "10");
 testOnLeak(newFakeMeasureOnLeak(10), Condition.Operator.LESS_THAN, "9", EvaluatedCondition.EvaluationStatus.OK, "10");
 testOnLeak(newFakeMeasureOnLeak(10), Condition.Operator.LESS_THAN, "10", EvaluatedCondition.EvaluationStatus.OK, "10");
 testOnLeak(newFakeMeasureOnLeak(10), Condition.Operator.LESS_THAN, "11", EvaluatedCondition.EvaluationStatus.ERROR, "10");
}

@Test
public void GREATER_THAN_double() {
 test(new FakeMeasure(10.1d), Condition.Operator.GREATER_THAN, "10.2", EvaluatedCondition.EvaluationStatus.OK, "10.1");
 test(new FakeMeasure(10.2d), Condition.Operator.GREATER_THAN, "10.2", EvaluatedCondition.EvaluationStatus.OK, "10.2");
 test(new FakeMeasure(10.3d), Condition.Operator.GREATER_THAN, "10.2", EvaluatedCondition.EvaluationStatus.ERROR, "10.3");
}

private void validateQualityGate(DbSession dbSession, OrganizationDto organizationDto, String name) {
 checkQualityGateDoesNotAlreadyExist(dbSession, organizationDto, name);
}

public static Builder newBuilder() {
 return new Builder();
}

private MetricDto insertMetric(Metric.ValueType type) {
 return insertMetric(type, "key");
}

private void testOnLeak(QualityGateEvaluator.Measure measure, Condition.Operator operator, String errorThreshold, EvaluatedCondition.EvaluationStatus expectedStatus,
 @Nullable String expectedValue) {
 Condition condition = new Condition("new_foo", operator, errorThreshold);
 EvaluatedCondition result = ConditionEvaluator.evaluate(condition, new FakeMeasures(measure));
 assertThat(result.getStatus()).isEqualTo(expectedStatus);
 if (expectedValue == null) {
  assertThat(result.getValue()).isNotPresent();
 } else {
  assertThat(result.getValue()).hasValue(expectedValue);
 }
}

@Test
public void GREATER_THAN_int() {
 test(new FakeMeasure(10), Condition.Operator.GREATER_THAN, "9", EvaluatedCondition.EvaluationStatus.ERROR, "10");
 test(new FakeMeasure(10), Condition.Operator.GREATER_THAN, "10", EvaluatedCondition.EvaluationStatus.OK, "10");
 test(new FakeMeasure(10), Condition.Operator.GREATER_THAN, "11", EvaluatedCondition.EvaluationStatus.OK, "10");
 testOnLeak(newFakeMeasureOnLeak(10), Condition.Operator.GREATER_THAN, "9", EvaluatedCondition.EvaluationStatus.ERROR, "10");
 testOnLeak(newFakeMeasureOnLeak(10), Condition.Operator.GREATER_THAN, "10", EvaluatedCondition.EvaluationStatus.OK, "10");
 testOnLeak(newFakeMeasureOnLeak(10), Condition.Operator.GREATER_THAN, "11", EvaluatedCondition.EvaluationStatus.OK, "10");
}

@Test
public void LESS_THAN_double() {
 test(new FakeMeasure(10.1d), Condition.Operator.LESS_THAN, "10.2", EvaluatedCondition.EvaluationStatus.ERROR, "10.1");
 test(new FakeMeasure(10.2d), Condition.Operator.LESS_THAN, "10.2", EvaluatedCondition.EvaluationStatus.OK, "10.2");
 test(new FakeMeasure(10.3d), Condition.Operator.LESS_THAN, "10.2", EvaluatedCondition.EvaluationStatus.OK, "10.3");
}

@Test
public void no_value_present() {
 test(new FakeMeasure((Integer) null), Condition.Operator.LESS_THAN, "9", EvaluatedCondition.EvaluationStatus.OK, null);
 test(null, Condition.Operator.LESS_THAN, "9", EvaluatedCondition.EvaluationStatus.OK, null);
}

@Test
public void evaluate_throws_IAE_if_fail_to_parse_threshold() {
 expectedException.expect(IllegalArgumentException.class);
 expectedException.expectMessage("Quality Gate: unable to parse threshold '9bar' to compare against foo");
 test(new FakeMeasure(10), Condition.Operator.LESS_THAN, "9bar", EvaluatedCondition.EvaluationStatus.ERROR, "10da");
}