enforce a maximum number of classes per file (max-classes-per-file)
Files containing multiple classes can often result in a less navigable and poorly structured codebase. Best practice is to keep each file limited to a single responsibility.
Rule Details
This rule enforces that each file may contain only a particular number of classes and no more.
Examples of incorrect code for this rule:
/*eslint max-classes-per-file: "error"*/ class Foo {} class Bar {}
Examples of correct code for this rule:
/*eslint max-classes-per-file: "error"*/ class Foo {}
Options
This rule may be configured with either an object or a number.
If the option is an object, it may contain one or both of:
-
ignoreExpressions
: a boolean option (defaulted tofalse
) to ignore class expressions. -
max
: a numeric option (defaulted to 1) to specify the maximum number of classes.
For example:
{ "max-classes-per-file": ["error", 1] }
{ "max-classes-per-file": [ "error", { "ignoreExpressions": true, "max": 2 } ] }
Examples of correct code for this rule with the max
option set to 2
:
/* eslint max-classes-per-file: ["error", 2] */ class Foo {} class Bar {}
Examples of correct code for this rule with the ignoreExpressions
option set to true
:
/* eslint max-classes-per-file: ["error", { ignoreExpressions: true }] */ class VisitorFactory { forDescriptor(descriptor) { return class { visit(node) { return `Visiting ${descriptor}.`; } }; } }
Version
This rule was introduced in ESLint 5.0.0-alpha.3.
Resources
© OpenJS Foundation and other contributors
Licensed under the MIT License.
https://eslint.org/docs/rules/max-classes-per-file