detekt

detekt documentation

Version in MegaLinter: 1.23.7
Visit Official Web Site
See Index of problems detected by detekt

Configuration in MegaLinter

Enable detekt by adding KOTLIN_DETEKT in ENABLE_LINTERS variable
Disable detekt by adding KOTLIN_DETEKT in DISABLE_LINTERS variable

Variable	Description	Default value
KOTLIN_DETEKT_ARGUMENTS	User custom arguments to add in linter CLI call Ex: `-s --foo "bar"`
KOTLIN_DETEKT_COMMAND_REMOVE_ARGUMENTS	User custom arguments to remove from command line before calling the linter Ex: `-s --foo "bar"`
KOTLIN_DETEKT_CLI_LINT_MODE	Override default CLI lint mode ⚠️ As default value is project, overriding might not work - `file`: Calls the linter for each file - `list_of_files`: Call the linter with the list of files as argument - `project`: Call the linter from the root of the project	`project`
KOTLIN_DETEKT_FILE_EXTENSIONS	Allowed file extensions. `"*"` matches any extension, `""` matches empty extension. Empty list excludes all files Ex: `[".py", ""]`	`[".kt", ".kts"]`
KOTLIN_DETEKT_FILE_NAMES_REGEX	File name regex filters. Regular expression list for filtering files by their base names using regex full match. Empty list includes all files Ex: `["Dockerfile(-.+)?", "Jenkinsfile"]`	Include every file
KOTLIN_DETEKT_PRE_COMMANDS	List of bash commands to run before the linter	None
KOTLIN_DETEKT_POST_COMMANDS	List of bash commands to run after the linter	None
KOTLIN_DETEKT_UNSECURED_ENV_VARIABLES	List of env variables explicitly not filtered before calling KOTLIN_DETEKT and its pre/post commands	None
KOTLIN_DETEKT_DISABLE_ERRORS	Run linter but consider errors as warnings	`false`
KOTLIN_DETEKT_DISABLE_ERRORS_IF_LESS_THAN	Maximum number of errors allowed	`0`
KOTLIN_DETEKT_CLI_EXECUTABLE	Override CLI executable	`['detekt-cli']`

IDE Integration

Use detekt in your favorite IDE to catch errors before MegaLinter !

	IDE	Extension Name	Install
	Emacs	flycheck-kotlin	Visit Web Site
	vim	ale	Visit Web Site

MegaLinter Flavors

This linter is available in the following flavors

Flavor	Description	Embedded linters
all	Default MegaLinter Flavor	124
c_cpp	Optimized for pure C/C++ projects	54
cupcake	MegaLinter for the most commonly used languages	84
documentation	MegaLinter for documentation projects	49
dotnet	Optimized for C, C++, C# or VB based projects	62
dotnetweb	Optimized for C, C++, C# or VB based projects with JS/TS	71
go	Optimized for GO based projects	51
java	Optimized for JAVA based projects	53
javascript	Optimized for JAVASCRIPT or TYPESCRIPT based projects	59
php	Optimized for PHP based projects	54
python	Optimized for PYTHON based projects	62
ruby	Optimized for RUBY based projects	50
rust	Optimized for RUST based projects	50
salesforce	Optimized for Salesforce based projects	54
swift	Optimized for SWIFT based projects	50
terraform	Optimized for TERRAFORM based projects	54

Behind the scenes

How are identified applicable files

File extensions: .kt, .kts

How the linting is performed

detekt is called once on the whole project directory (project CLI lint mode)

filtering can not be done using MegaLinter configuration variables,it must be done using detekt configuration or ignore file (if existing)
VALIDATE_ALL_CODEBASE: false doesn't make detekt analyze only updated files

Example calls

detekt-cli

detekt-cli --report html:folder/kotlin_detekt_result.html

Help content

Usage: detekt [options]
  Options:
    --all-rules
      Activates all available (even unstable) rules.
      Default: false
    --auto-correct, -ac
      Allow rules to auto correct code if they support it. The default rule
      sets do NOT support auto correcting and won't change any line in the
      users code base. However custom rules can be written to support auto
      correcting. The additional 'formatting' rule set, added with
      '--plugins', does support it and needs this flag.
      Default: false
    --base-path, -bp
      Specifies a directory as the base path.Currently it impacts all file
      paths in the formatted reports. File paths in console output and txt
      report are not affected and remain as absolute paths.
    --baseline, -b
      If a baseline xml file is passed in, only new code smells not in the
      baseline are printed in the console.
    --build-upon-default-config
      Preconfigures detekt with a bunch of rules and some opinionated defaults
      for you. Allows additional provided configurations to override the
      defaults.
      Default: false
    --classpath, -cp
      EXPERIMENTAL: Paths where to find user class files and depending jar
      files. Used for type resolution.
    --config, -c
      Path to the config file (path/to/config.yml). Multiple configuration
      files can be specified with ',' or ';' as separator.
    --config-resource, -cr
      Path to the config resource on detekt's classpath (path/to/config.yml).
    --create-baseline, -cb
      Treats current analysis findings as a smell baseline for future detekt
      runs.
      Default: false
    --debug
      Prints extra information about configurations and extensions.
      Default: false
    --disable-default-rulesets, -dd
      Disables default rule sets.
      Default: false
    --excludes, -ex
      Globbing patterns describing paths to exclude from the analysis.
    --generate-config, -gc
      Export default config. Path can be specified with --config option
      (default path: default-detekt-config.yml)
      Default: false
    --help, -h
      Shows the usage.
    --includes, -in
      Globbing patterns describing paths to include in the analysis. Useful in
      combination with 'excludes' patterns.
    --input, -i
      Input paths to analyze. Multiple paths are separated by comma. If not
      specified the current working directory is used.
    --jdk-home
      EXPERIMENTAL: Use a custom JDK home directory to include into the
      classpath
    --jvm-target
      EXPERIMENTAL: Target version of the generated JVM bytecode that was
      generated during compilation and is now being used for type resolution
      (1.8, 9, 10, ..., 20)
      Default: 1.8
    --language-version
      EXPERIMENTAL: Compatibility mode for Kotlin language version X.Y,
      reports errors for all language features that came out later
      Possible Values: [1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1]
    --max-issues
      Return exit code 0 only when found issues count does not exceed
      specified issues count.
    --parallel
      Enables parallel compilation and analysis of source files. Do some
      benchmarks first before enabling this flag. Heuristics show performance
      benefits starting from 2000 lines of Kotlin code.
      Default: false
    --plugins, -p
      Extra paths to plugin jars separated by ',' or ';'.
    --report, -r
      Generates a report for given 'report-id' and stores it on given 'path'.
      Entry should consist of: [report-id:path]. Available 'report-id' values:
      'txt', 'xml', 'html', 'md', 'sarif'. These can also be used in
      combination with each other e.g. '-r txt:reports/detekt.txt -r
      xml:reports/detekt.xml'
    --version
      Prints the detekt CLI version.
      Default: false

Installation on mega-linter Docker image

Dockerfile commands :

# Parent descriptor install
ENV JAVA_HOME=/usr/lib/jvm/java-21-openjdk
ENV PATH="$JAVA_HOME/bin:${PATH}"
# Linter install
# renovate: datasource=github-tags depName=detekt/detekt
ARG DETEKT_VERSION=1.23.7

RUN curl --retry 5 --retry-delay 5 -sSLO https://github.com/detekt/detekt/releases/download/v${DETEKT_VERSION}/detekt-cli-${DETEKT_VERSION}.zip && \
    unzip detekt-cli-${DETEKT_VERSION}.zip && \
    chmod a+x detekt-cli-${DETEKT_VERSION}/bin/* && \
    chmod a+x detekt-cli-${DETEKT_VERSION}/lib/* && \
    mv -n detekt-cli-${DETEKT_VERSION}/bin/* usr/bin && \
    mv -n detekt-cli-${DETEKT_VERSION}/lib/* usr/lib