Codelyzer core rules

Lint rules encode logic for syntactic & semantic checks of TypeScript, HTML, CSS and Angular expressions source code.

TypeScript-specific

These rules find errors related to TypeScript or Angular features:

Functionality

These rules catch common errors in JS programming or otherwise confusing constructs that are prone to producing bugs:

• TS Only
  contextual-decorator - Ensures that classes use contextual decorators in its body.
• TS Only
  contextual-lifecycle - Ensures that classes use allowed lifecycle method in its body.
• TS Only
  no-attribute-decorator - Disallows usage of @Attribute decorator.
• TS Only
  no-lifecycle-call - Disallows explicit calls to lifecycle methods.
• TS Only
  no-output-native - Disallows naming directive outputs as standard DOM event.
• TS Only
  no-pipe-impure - Disallows the declaration of impure pipes.
• TS Only
  prefer-on-push-component-change-detection - Enforces component’s change detection to ChangeDetectionStrategy.OnPush.
• TS Only
  template-accessibility-alt-text - Enforces alternate text for elements which require the alt, aria-label, aria-labelledby attributes
• TS Only
  template-accessibility-elements-content - Ensures that the heading, anchor and button elements have content in it
• TS Only
  template-accessibility-label-for - Checks if a label component is associated with a form element
• TS Only
  template-accessibility-tabindex-no-positive - Ensures that the tabindex attribute is not positive
• TS Only
  template-accessibility-table-scope - Ensures that scope is not used on any element except th
• TS Only
  template-accessibility-valid-aria - Ensures that the correct ARIA attributes are used
• TS Only Has Fixer
  template-banana-in-box - Ensures that the two-way data binding syntax is correct.
• TS Only
  template-click-events-have-key-events - Ensures that the click event is accompanied with at least one key event keyup, keydown or keypress
• TS Only
  template-mouse-events-have-key-events - Ensures that the Mouse Events mouseover and mouseout are accompanied with Key Events focus and blur
• TS Only
  template-no-any - Disallows using ‘$any’ in templates.
• TS Only
  template-no-autofocus - Ensure that autofocus property is not used
• TS Only
  template-no-distracting-elements - Enforces that no distracting elements are used
• TS Only
  template-no-negated-async - Ensures that strict equality is used when evaluating negations on async pipe output.
• TS Only
  use-injectable-provided-in - Enforces classes decorated with @Injectable to use the ‘providedIn’ property.
• TS Only
  use-lifecycle-interface - Ensures classes implement lifecycle interfaces corresponding to the declared lifecycle methods.

Maintainability

These rules make code maintenance easier:

• TS Only
  component-max-inline-declarations - Disallows having too many lines in inline template and styles. Forces separate template or styles file creation.
• TS Only
  no-conflicting-lifecycle - Ensures that directives not implement conflicting lifecycle interfaces.
• TS Only
  no-forward-ref - Disallows usage of forwardRef references for DI.
• TS Only
  no-input-prefix - Input names should not be prefixed by the configured disallowed prefixes.
• TS Only
  no-input-rename - Disallows renaming directive inputs by providing a string to the decorator.
• TS Only
  no-output-on-prefix - Name events without the prefix on.
• TS Only
  no-output-rename - Disallows renaming directive outputs by providing a string to the decorator.
• TS Only Has Fixer
  no-unused-css - Disallows having an unused CSS rule in the component’s stylesheet.
• TS Only
  prefer-output-readonly - Prefer to declare @Output as readonly since they are not supposed to be reassigned.
• TS Only
  relative-url-prefix - The ./ prefix is standard syntax for relative URLs; don’t depend on Angular’s current ability to do without that prefix.
• TS Only
  template-conditional-complexity - The condition complexity shouldn’t exceed a rational limit in a template.
• TS Only
  template-cyclomatic-complexity - Checks cyclomatic complexity against a specified limit. It is a quantitative measure of the number of linearly independent paths through a program’s source code
• TS Only
  template-i18n - Ensures following best practices for i18n.
• TS Only
  template-no-call-expression - Disallows calling expressions in templates, except for output handlers.
• TS Only
  template-use-track-by-function - Ensures trackBy function is used.
• TS Only
  use-component-selector - Component selector must be declared.
• TS Only
  use-component-view-encapsulation - Disallows using ViewEncapsulation.None.
• TS Only
  use-pipe-decorator - Ensures that classes implementing PipeTransform interface use @Pipe decorator.
• TS Only
  use-pipe-transform-interface - Ensures that classes decorated with @Pipe implement PipeTransform interface.

Style

These rules enforce consistent style across your codebase:

• TS Only Has Fixer
  angular-whitespace - Ensures the proper formatting of Angular expressions.
• TS Only
  component-class-suffix - Classes decorated with @Component must have suffix “Component” (or custom) in their name.
• TS Only
  component-selector - Component selectors should follow given naming rules.
• TS Only
  directive-class-suffix - Classes decorated with @Directive must have suffix “Directive” (or custom) in their name.
• TS Only
  directive-selector - Directive selectors should follow given naming rules.
• TS Only Has Fixer
  import-destructuring-spacing - Ensures imports are consistent and tidy.
• TS Only
  no-host-metadata-property - Disallows usage of the host metadata property.
• TS Only
  no-inputs-metadata-property - Disallows usage of the inputs metadata property.
• TS Only
  no-outputs-metadata-property - Disallows usage of the outputs metadata property.
• TS Only
  no-queries-metadata-property - Disallows usage of the queries metadata property.
• TS Only
  pipe-prefix - Enforce consistent prefix for pipes.
• TS Only
  prefer-inline-decorator - Ensures that declarations are on the same line as its decorator(s).