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Add MCP resource documenting dcover CLI options
Expose comprehensive dcover configuration documentation through an MCP resource (data://config). This allows LLM clients to query available dcover options and their descriptions, enabling intelligent tool usage and better test generation configurations. The resource includes 50+ dcover CLI options covering: - Test framework selection - Mocking strategies (Mockito, Spring) - Coverage options - Build system preferences - Output customization - Security and sandbox settings Marked as read-only and idempotent for efficient caching.
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‎covermcp/server.py‎

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@@ -91,6 +91,173 @@ def write_tests() -> list[dict]:
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]
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@mcp.resource(
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"data://config",
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description="Provides the configuration options for creating tests with Diffblue Cover.",
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mime_type="application/json",
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annotations={"readOnlyHint": True, "idempotentHint": True},
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)
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def create_options() -> dict:
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"""Provide comprehensive dcover CLI option documentation.
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Exposes 50+ dcover configuration options covering test frameworks,
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mocking, coverage, build systems, and Spring configurations. Enables
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LLMs to discover and use dcover features intelligently.
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Returns:
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dict: Mapping of CLI option names to descriptions. Keys can be
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passed directly to dcover via the create tool's args parameter.
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Note:
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Exposed at URI "data://config". Marked read-only and idempotent
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for efficient caching.
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"""
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return {
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"--active-profiles": "The comma separated list of profiles to use where creating Spring tests. Not providing a "
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"value will use the default profile.",
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"--allow-jni": "The comma separated list of additional JNI library name prefixes that should be usable within "
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"the sandbox when creating and evaluating tests. JNI library names are the strings supplied in "
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"calls to System.loadLibrary(...). By default only JDK provided libraries are allowed. ",
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"--annotate-suppress-warnings": "Adds the @SuppressWarning annotation to methods with the given tags, for "
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'example: "--annotate-suppress-warnings=unused,rawtypes", would produce '
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'@SuppressWarnings({"unused","rawtypes"})',
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"--batch": "Do not display progress bars. Automatically enabled when environment variable CI=true, or when "
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"using the Cover MCP server.",
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"--class-name-template=<template>": "How test classes are named, where Cover will attempt to insert Tests. "
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"The same template must be used in dcover create and dcover validate "
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"executions. Available replacements: ${CLASS} - the name of the class "
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"under test. Default: ${CLASS}DiffblueTest, Tip: Quote or escape "
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"templates to stop your shell mangling them.",
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"--compliance-level=<value>": "By default dcover automatically detects the Java compliance value, or falls "
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"back to 1.8. Use this option to set a specific level from 3 to 17.",
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"--cover-all-enums": "Attempt to generate tests using all possible values for enum types used as a parameter, "
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"or to generate test cases that cause the method-under-test to return all possible values "
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"of enum types. (This will happen even if this provides no additional line coverage.) ",
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"--report-file=<report>": "Location of the JSON-formatted test-writing summary report.",
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"--coverage-reports": "Once test creation has completed, run JaCoCo commands to get separate coverage reports "
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"for the Diffblue and the non-Diffblue tests. All tests that follow the naming pattern "
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"(e.g. *DiffblueTest.java) are considered, not just the tests that were created in the "
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"current run. By default, the reports are placed in .diffblue/reports/. This option is "
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"incompatible with --class-name-template. The command to create the JaCoCo reports can "
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"be customised using a custom DiffblueBuild.yaml configuration.",
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"--classpath=<value>": "A ':' separated list of directories and JAR archives to search for class files.",
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"--test-output-dir=<value>": "Directory where the Diffblue tests are written.",
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"--define=<String=String>": "Set system properties to be applied when running tests.",
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"--[no-]descriptive-test-names": "Use descriptive test names.",
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"--diffblue-class-name-template=<template>": "How the Diffblue test classes are named. Contents will be "
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"treated as MaintainedByDiffblue. The same template must be used "
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"in dcover create and dcover validate executions. Available "
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"replacements: "
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"${CLASS} - the name of the class under test."
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"Default: ${CLASS}DiffblueTest Tip: Quote or escape templates to "
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"stop your shell mangling them.",
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"--disable-sandbox": "Uses a more permissive security manager policy for the methods under test. Use with "
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"caution: This allows the execution of potentially unsafe code during test creation, "
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"which may damage your system environment.",
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"--preflight": "Check that the project's environment is ready to run Diffblue Cover.",
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"--exclude=<entryPointExclusions>": "Package/class/method to exclude from test-writing. For example, with the "
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"specification: dcover create --exclude='com.example.*.model.*' Diffblue "
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"Cover will exclude all classes in a model package.",
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"--environment=<String=String>": "Set environment variables to be applied when running dcover.",
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"--exclude-method=<methodExclusions>": "Methods that should not be used in tests. For example, with the "
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"specification: dcover create --exclude-method='com.example.*. model.*' "
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"Diffblue Cover test will not make any calls to methods in the model "
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"package. Environment: DIFFBLUE_EXCLUDE_METHOD",
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"--exclude-modules=<module>[, <module>...]": "Exclude specified modules from the discovered module list. "
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"Environment: DIFFBLUE_EXCLUDE_MODULES",
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"--exclude-trivial-methods": "Do not write tests for trivial methods.",
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"--gradle": "Make Cover prefer the use of Gradle build system.",
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"--help": "Show this help message and exit.",
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"--include-modules=<module>[, <module>...]": "Include only specified modules from the discovered module list. "
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"Environment: DIFFBLUE_INCLUDE_MODULES",
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"--keep-partial-tests": "Keep all created tests, even partial tests. These tests may prevent your project from "
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"compiling successfully. The provided tests may include tests without assertions, "
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"non-compiling tests, non-deterministic tests, tests that throw, and tests that "
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"violate the security policy.",
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"--location=<value>": "The location in Reports where the uploaded project will be placed.",
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"--maven": "Make Cover prefer the use of Maven build system.",
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"--max-assertions-per-test=<value>": "Set the maximum number of assertions generated per test. "
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"Environment: DIFFBLUE_MAX_ASSERTIONS_PER_TEST",
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"--method-name-template=<template>": "Tell dcover how to name test methods. "
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"Available replacements: "
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"${INNER} - the name of the inner class for the method under test, "
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"or blank. "
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"${UNIT} - a summary of the methods under test. "
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"${METHOD} - the name of the first method under test. "
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"${GIVEN} - a summary of the conditions before testing, or blank if no "
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"summary is available. ${WHEN} - a summary of the conditions under test, "
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"or blank if no summary is available. "
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"${THEN} - summary of the test's consequences, or blank if no summary is "
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"available. "
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"${_} - an underscore, or a blank string if there are no values to "
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"separate. Default: test${INNER}${UNIT}${_}${GIVEN}${_}${WHEN}${_}${THEN} "
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"For example, given an inner class Foo with an equals(Object) and "
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"hashCode() implementation, a test method might be named "
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"testFooEqualsAndHashCode_whenOtherIsEqual_thenRet urnEqual(). "
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"Tip: Quote or escape templates to stop your shell mangling them.",
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"--mock=<value>[, <value>...]": "Prefixes of package/class to mock using Mockito.mock(). The class containing "
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"the method under test is never mocked. Non-void, non-private instance methods "
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"are stubbed with when(). thenReturn().",
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"--mock-construction=<value>[, <value>...]": "Fully qualified names of classes for which to mock constructors "
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"using Mockito.mockConstruction. This feature is available with "
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"Mockito 3.5.0 and above, when using the inline mock maker. "
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"Constructors of the method under test will not be mocked.",
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"--mock-method-returns": "Make Cover to be more willing to accept returning mock values from mocked methods. "
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"This may allow Cover to write more tests for code which has complex class "
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"dependencies, however it may also degrade coverage for code where business logic is "
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"complex.",
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"--mock-static=<value>[, <value>...]": "Names of classes to mock using Mockito. mockStatic(). This feature is "
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"available with Mockito 3.4.0 and above, when inline mocking is "
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"enabled. If the method under test is static its class will not be "
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"mocked.",
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"--name=<value>": "Name of reports bundle. Defaults to the current timestamp, or the latest commit hash when "
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"used within Git.",
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"--new-jacoco-coverage": "Only create tests that add coverage to the project.",
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"--no-spring-boot-tests": "[Beta] When enabled, tests will not use Spring Boot for dependency injection, "
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"instead falling back to other mechanisms such as Mockito's @InjectMocks if "
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"available.",
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"--no-spring-tests": "When enabled, tests will not use Spring contexts for dependency injection",
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"--output-comments": "Used to suppress the // Arrange, // Act, and // Assert comments in tests written by "
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"Diffblue Cover (set to false). Default is true (show comments).",
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"--patch-only=<value>": "Specifies a patch file to have dcover only create tests for the code changes covered "
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"by the patch and classes that call classes in the patch. For a multi-module project, "
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"generate the patch at the root of the project and provide the absolute path to the "
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"patch file, using `--working-directory` with the relative path to the module. The "
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"same patch file can be used for each module.",
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"--project-name=<value>": "Name of the project shown in Reports of the project being uploaded.",
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"--fix-build": "Perform refactorings to fix issues found while attempting to create tests.",
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"--report-password=<value>": "Password for authentication when uploading Diffblue Cover Reports. Password can "
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"alternatively be set via the environment variable, "
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"DIFFBLUE_COVER_REPORTS_PASSWORD",
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"--report-username=<value>": "Username for authentication when uploading Diffblue Cover Reports. Username can "
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"alternatively be set via the environment variable, "
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"DIFFBLUE_COVER_REPORTS_USERNAME",
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"--resume-from-module=<module>": "Resume iteration from the specified module. "
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"Environment: DIFFBLUE_RESUME_FROM_MODULE",
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"--spring-configuration=<value>[, <value>...]": "The Spring configuration classes to use in tests.",
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"--spring-integration-tests": "Tests created for Spring components will use mocking only for Repository "
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"dependencies. All other dependencies will be resolved by Spring directly. Not "
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"applied when creating tests for @Controller classes.",
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"--strict": "Forces the strict definition of all project environment options by you - Diffblue Cover will not "
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"attempt to make an automated selection. For example, if multiple testing frameworks are "
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"configured for your project then running with this option will lead to an error, unless you "
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"define which testing framework Cover should use when writing tests. Without this option, Cover "
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"would choose one of the testing frameworks for you, and proceed.",
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"--testing-framework=<testFrameworkArgument>": "dcover automatically determines the current version of the "
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"testing framework in use. This option allows you to specify "
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"the framework from 'junit-4.7' to 'junit-5.8', or 'testng'. You"
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" can also specify 'junit-4' (any version of JUnit 4) and "
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"'junit-5' (any version of JUnit 5)",
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"--upload[=<URL>]": "URL of a Cover Reports server to upload reports to.",
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"--version": "Print version information and exit.",
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"--verbose": "Display more detailed information.",
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"--preflight-without-tests": "During the preflight checks, dcover will run the existing tests. To disable that "
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"behavior specify this option",
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"--working-directory=<value>": "Set the working directory for running dcover. "
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"Environment: DIFFBLUE_WORKING_DIRECTORY",
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} # fmt: skip
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@mcp.tool()
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# Ignore "too many parameters for a method" check
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async def create( # noqa: PLR0913

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