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Java Spring file writer sample

This sample demonstrates the test-suite-writer generator, which outputs test suites as JSON or YAML files instead of executable code. This is useful for data-driven testing frameworks or when you need to process test cases programmatically.

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Overview

Property Value
Module samples:java-spring-file-writer
Generator test-suite-writer
Output format JSON (with YAML variant)
Output location src/test/resources/

What it demonstrates

  • Using the test-suite-writer generator to produce JSON test suites
  • MERGE mode: Preserving manual edits when regenerating
  • Protected fields: Preventing overwrite of specific test case fields
  • Multiple generation tasks: JSON and YAML outputs from the same spec
  • Reading test suites at runtime with the model library

Plugin configuration

openApiTestGenerator {
    specFile.set(file("${rootDir}/samples/openapi.yaml").toURI().toString())
    outputDir.set(layout.projectDirectory.dir("src/test/resources"))
    generator.set("test-suite-writer")

    generatorOptions.putAll(
        mapOf(
            "outputFileName" to "openapi-test-suites.json",
            "writeMode" to "MERGE",
            "preventOverwriteSuites" to "false",
            "preventOverwriteCases" to "true",
            "protectedTestCaseFields" to "expectedStatusCode,expectedBody",
            "indent" to "    ",
        )
    )

    testGenerationSettings {
        ignoreTestCases.putAll(mapOf(
            "/orders" to mapOf("GET" to listOf("Invalid Query page parameter: Integer Breaking"))
        ))
        validSecurityValues.putAll(mapOf("ApiKeyAuth" to "test-api-key-123"))
        overrideBasicTestData.putAll(mapOf("invalidApiKey" to "unrealistic_key"))
        maxSchemaDepth.set(15)
        errorMode.set(ErrorMode.FAIL_FAST)
    }
}

Key generator options

Option Value Description
outputFileName openapi-test-suites.json Name of the output file
writeMode MERGE Merge with existing file instead of overwriting
preventOverwriteCases true Don't overwrite existing test cases
protectedTestCaseFields expectedStatusCode,expectedBody Fields that won't be overwritten during merge
indent 4-space indentation for readability

Additional YAML generation

The sample also registers a second task that generates YAML format using a config file:

tasks.register<OpenApiTestGeneratorTask>("generateOpenApiTestsYaml") {
    configFile.set("open-api-test-generation-config.yaml")
    testGenerationSettings {
        validSecurityValues.putAll(mapOf("ApiKeyAuth" to "test-api-key-12"))
    }
}

See open-api-test-generation-config.yaml for the YAML config example.

Output structure

The generated JSON file contains an array of test suites:

[
  {
    "operationPath": "/users",
    "operationName": "listUsers",
    "httpMethod": "GET",
    "testCases": [
      {
        "name": "Valid request",
        "description": "Valid request for listUsers",
        "expectedStatusCode": 200,
        "headers": [
          { "key": "X-API-Key", "value": "test-api-key-123" }
        ],
        "queryParams": [],
        "pathParams": [],
        "cookies": [],
        "body": null
      },
      {
        "name": "Missing security: AllSecurityMissed",
        "description": "Test case without any security credentials",
        "expectedStatusCode": 401,
        "headers": [],
        ...
      }
    ]
  }
]

Running the tests

The sample includes a parameterized test that reads the JSON file and executes each test case:

# Generate test suites
./gradlew :samples:java-spring-file-writer:generateOpenApiTests

# Generate YAML variant
./gradlew :samples:java-spring-file-writer:generateOpenApiTestsYaml

# Run all tests (generation is wired to processTestResources)
./gradlew :samples:java-spring-file-writer:test

Using test suites at runtime

The sample depends on openapi.testgen.model to deserialize test suites:

dependencies {
    implementation("art.galushko:openapi.testgen.model")
}

ObjectMapper mapper = new ObjectMapper();
List<TestSuite> suites = mapper.readValue(
    new File("src/test/resources/openapi-test-suites.json"),
    new TypeReference<List<TestSuite>>() {}
);

for (TestSuite suite : suites) {
    for (TestCase testCase : suite.getTestCases()) {
        // Execute test case with your HTTP client
    }
}

Merge behavior

With writeMode: MERGE:

  1. New test suites are added to the file
  2. Existing test suites are updated with new test cases
  3. Existing test cases (matched by name) preserve their protectedTestCaseFields
  4. Manual edits to expectedStatusCode or expectedBody survive regeneration

This allows you to:

  • Generate initial test cases automatically
  • Manually adjust expected values for your specific implementation
  • Regenerate when the OpenAPI spec changes without losing manual edits