Detekt rules for Jetpack Compose

A set of Detekt rules to help prevent common errors in projects using Jetpack Compose.

Rules

Here are some highlights of rules in this rule set:

• ReusedModifierInstance finds usages of modifier parameter on non-top-level children of a composable function. This tends to happen during refactorings and often leads to incorrect rendering of a composable

• UnnecessaryEventHandlerParameter suggests hoisting event argument passing to the upper level which often simplifies individual composable components

• ModifierHeightWithText suggests using Modifier.heightIn() instead of Modifier.height() on a layouts which have Text children, so that if the text turns out to be long and would wrap, layout will not cut it off

• ComposableEventParameterNaming ensures that all event handler parameters of composable functions are named in the same Compose-like style, i.e. they have on prefix and do not use past tense

• ComposableParametersOrdering suggests the correct grouping and order of composable functions' parameters, ensures the correct position of the Modifier parameter

• ModifierDefaultValue ensures that modifier parameter has a correct default value

• MissingModifierDefaultValue checks if modifier default value is specified

• PublicComposablePreview finds and reports composable previews which are not marked as private

• TopLevelComposableFunctions ensures that all composable functions are top-level functions (disabled by default)

• ComposableFunctionName ensures that Composable functions which return Unit should start with upper-case while the ones that return a value should start with lower case

• and others...

Rules can be individually turned on or off in the configuration file.
More detailed rule descriptions with code snippets can be found in the Wiki.

Running checks

Some rules will only work if detekt is running in a type resolution mode, so make sure it is configured for your build if you want to make full use of them.

Installation and configuration

Add detekt rules plugin in your build.gradle (or use any other supported method):

dependencies {
  detektPlugins("ru.kode:detekt-rules-compose:1.4.0")
}

and then add this configuration section to your detekt-config.yml to activate the rules:

compose:
  ReusedModifierInstance:
    active: true
  UnnecessaryEventHandlerParameter:
    active: true
  ComposableEventParameterNaming:
    active: true
  ComposableParametersOrdering:
    active: true
  ModifierHeightWithText:
    active: true
  MissingModifierDefaultValue:
    active: true
  PublicComposablePreview:
    active: true
  TopLevelComposableFunctions:
    active: true
    allowInObjects: false
  ComposableFunctionName:
    active: true
  ConditionCouldBeLifted:
    active: true
    ignoreCallsWithArgumentNames: [ 'modifier', 'contentAlignment' ]

Detekt configuration for Compose

Detekt manual contains few useful tips on how to configure Detekt in Compose-based projects, check them out!

Contributors

Maintained by KODE and Contributors ❤️

License

MIT License

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