SonarSource/sonarqube · error · IllegalArgumentException

Tags should be set either by using 'tags = java' or 'tags IN

Error message

Tags should be set either by using 'tags = java' or 'tags IN (finance, platform)'

What it means

The tags criterion in the project measures/search WS must use either '=' with one tag or 'IN' with a non-empty tag list. processTags throws this IllegalArgumentException when another operator is used or the value list is empty.

Source

Thrown at server/sonar-webserver-webapi/src/main/java/org/sonar/server/component/ws/ProjectMeasuresQueryFactory.java:115

      return;
    }
    throw new IllegalArgumentException("Languages should be set either by using 'languages = java' or 'languages IN (java, js)'");
  }

  private static void processTags(Criterion criterion, ProjectMeasuresQuery query) {
    checkOperator(criterion);
    Operator operator = criterion.getOperator();
    String value = criterion.getValue();
    List<String> values = criterion.getValues();
    if (value != null && EQ.equals(operator)) {
      query.setTags(singleton(value));
      return;
    }
    if (!values.isEmpty() && IN.equals(operator)) {
      query.setTags(new HashSet<>(values));
      return;
    }
    throw new IllegalArgumentException("Tags should be set either by using 'tags = java' or 'tags IN (finance, platform)'");
  }

  private static void processQualifier(Criterion criterion, ProjectMeasuresQuery query) {
    checkOperator(criterion);
    checkValue(criterion);
    Operator operator = criterion.getOperator();
    String value = criterion.getValue();
    checkArgument(EQ.equals(operator), "Only equals operator is available for qualifier criteria");
    String qualifier = Stream.of(ComponentQualifiers.APP, ComponentQualifiers.PROJECT).filter(q -> q.equalsIgnoreCase(value)).findFirst()
      .orElseThrow(() -> new IllegalArgumentException(format("Unknown qualifier : '%s'", value)));
    query.setQualifiers(Sets.newHashSet(qualifier));
  }

  private static void processQuery(Criterion criterion, ProjectMeasuresQuery query) {
    checkOperator(criterion);
    Operator operatorValue = criterion.getOperator();
    String value = criterion.getValue();
    checkArgument(value != null, "Query is invalid");

View on GitHub (pinned to 184c821202)

Solutions

Use 'tags = finance' for one tag or 'tags IN (finance, platform)' for several.
Ensure at least one tag value is present and non-empty.
Only use comparison operators (=, IN) for tags, not relational ones.

Example fix

// before
String criteria = "tags > finance";
// after
String criteria = "tags IN (finance, platform)";

Defensive patterns

Strategy: validation

Validate before calling

Set<String> allowed = Set.of("=", "IN");
if (criterion.getKey().equals("tags") && (!allowed.contains(criterion.getOperator()) || criterion.getValues().isEmpty())) {
  throw new IllegalArgumentException("tags requires '=' or 'IN' with at least one tag");
}

Try / catch

try {
  response = ws.searchProjects(criteria);
} catch (IllegalArgumentException e) {
  if (e.getMessage().contains("Tags should be set")) {
    criteria = criteria.replaceAll("tags\\s*[^=I][^N]?.*", "tags IN (" + String.join(", ", tags) + ")");
  } else throw e;
}

Prevention

Only generate 'tags = X' or 'tags IN (X, Y)' forms.
Check the tag list is non-empty before building the criterion.
Do not copy operators from numeric criteria (>, <) onto tags.

When it happens

Trigger: Calling api/measures/search_projects with criteria like 'tags > finance', 'tags != platform', 'tags =' (no value), or 'tags IN ()'.

Common situations: Hand-edited saved filters; scripting against the WS with operators copied from numeric criteria (where >, < are valid); empty tag variables interpolated into the criteria string.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

AI-assisted analysis of SonarSource/sonarqube@184c821202 (2026-09-09). Data as JSON: /api/errors/0cf8afc5709ef279. Report an issue: GitHub.