What causes "Test tool "{testTool}" is not supported or misspelled." in OpenAPITools/openapi-generator?

Set `-p test=junit` or `-p test=spock` (exact, case-sensitive strings).

OpenAPITools/openapi-generator · error · RuntimeException

Test tool "{testTool}" is not supported or misspelled.

Error message

Test tool "{testTool}" is not supported or misspelled.

What it means

Thrown by JavaMicronautAbstractCodegen.processOpts while validating the 'test' additional property (OPT_TEST) for the java-micronaut / java-micronaut-server generators. The switch only wires two test frameworks: 'junit' (OPT_TEST_JUNIT) and 'spock' (OPT_TEST_SPOCK, Groovy-based); any other string aborts generation before any file is written. If 'test' is not supplied, the generator defaults to junit.

Source

Thrown at modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaMicronautAbstractCodegen.java:287

                case OPT_BUILD_GRADLE:
                case OPT_BUILD_MAVEN:
                case OPT_BUILD_ALL:
                    this.buildTool = (String) additionalProperties.get(OPT_BUILD);
                    break;
                default:
                    throw new RuntimeException("Build tool \"" + additionalProperties.get(OPT_BUILD) + "\" is not supported or misspelled.");
            }
        }
        additionalProperties.put(OPT_BUILD, buildTool);

        if (additionalProperties.containsKey(OPT_TEST)) {
            switch ((String) additionalProperties.get(OPT_TEST)) {
                case OPT_TEST_JUNIT:
                case OPT_TEST_SPOCK:
                    this.testTool = (String) additionalProperties.get(OPT_TEST);
                    break;
                default:
                    throw new RuntimeException("Test tool \"" + additionalProperties.get(OPT_TEST) + "\" is not supported or misspelled.");
            }
        }
        additionalProperties.put(OPT_TEST, testTool);
        if (testTool.equals(OPT_TEST_JUNIT)) {
            additionalProperties.put("isTestJunit", true);
        } else if (testTool.equals(OPT_TEST_SPOCK)) {
            additionalProperties.put("isTestSpock", true);
        }

        if (additionalProperties.containsKey(OPT_GENERATE_SWAGGER_ANNOTATIONS)) {
            String value = String.valueOf(additionalProperties.get(OPT_GENERATE_SWAGGER_ANNOTATIONS));
            switch (value) {
                case OPT_GENERATE_SWAGGER_ANNOTATIONS_SWAGGER_1:
                    this.generateSwaggerAnnotations = OPT_GENERATE_SWAGGER_ANNOTATIONS_SWAGGER_1;
                    break;
                case OPT_GENERATE_SWAGGER_ANNOTATIONS_SWAGGER_2:
                case OPT_GENERATE_SWAGGER_ANNOTATIONS_TRUE:
                    this.generateSwaggerAnnotations = OPT_GENERATE_SWAGGER_ANNOTATIONS_SWAGGER_2;

View on GitHub (pinned to fcec517be3)

Solutions

Set `-p test=junit` or `-p test=spock` (exact, case-sensitive strings).
Omit the 'test' option entirely — the generator defaults to junit.
If you pasted options from another generator's docs, re-check against `openapi-generator-cli config-help -g java-micronaut-server`, which lists exactly junit and spock for testToolMap.
Inspect the value in your config file for trailing spaces or non-ASCII quotes.

Example fix

# before
openapi-generator-cli generate -g java-micronaut-server -i api.yaml -p test=junit5
# after
openapi-generator-cli generate -g java-micronaut-server -i api.yaml -p test=junit

Defensive patterns

Strategy: validation

Validate before calling

# shell: gate the option before invoking the CLI
test_tool="${TEST_TOOL:-junit}"
case "$test_tool" in
  junit|spock) ;;
  *) echo "test must be 'junit' or 'spock', got: $test_tool" >&2; exit 2 ;;
esac
openapi-generator-cli generate -g java-micronaut-server -i api.yaml -p test="$test_tool"

Type guard

private static final java.util.Set<String> MICRONAUT_TEST_TOOLS = java.util.Set.of("junit", "spock");

boolean isValidMicronautTestTool(String value) {
    return value != null && MICRONAUT_TEST_TOOLS.contains(value);
}

Try / catch

try {
    new DefaultGenerator().opts(clientOptInput).generate();
} catch (RuntimeException e) {
    // deterministic config error: report and stop, never retry
    throw new IllegalStateException("Micronaut generator config rejected: " + e.getMessage(), e);
}

Prevention

Keep per-generator option allowlists in one build script instead of hand-typed -p flags.
Run `openapi-generator-cli config-help -g java-micronaut-server` once and pin the printed enum values.
Treat any 'not supported or misspelled' message as a typo in an option value, not a generator bug.

When it happens

Trigger: Running `openapi-generator-cli generate -g java-micronaut-server -i api.yaml -p test=junit5` (or any value other than exactly 'junit' or 'spock': 'Junit', 'spock2', 'testng', 'junit-jupiter'). Also reachable via the additionalProperties block of a YAML/JSON config file, or programmatically through addAdditionalProperty("test", value).

Common situations: Copying CLI options from a Spring/Quarkus generator recipe that names test frameworks differently (junit5, junit-jupiter); assuming version-suffixed names are aliases; stray whitespace or smart quotes around the value in YAML/JSON config files.

Related errors

AI-assisted analysis of OpenAPITools/openapi-generator@fcec517be3 (2026-08-22). Data as JSON: /api/errors/e3fe5f35c0902ae8. Report an issue: GitHub.