enforce a maximum file length (max-lines)
Some people consider large files a code smell. Large files tend to do a lot of things and can make it hard following what's going. While there is not an objective maximum number of lines considered acceptable in a file, most people would agree it should not be in the thousands. Recommendations usually range from 100 to 500 lines.
Rule Details
This rule enforces a maximum number of lines per file, in order to aid in maintainability and reduce complexity.
Options
This rule has a number or object option:
"max"
(default300
) enforces a maximum number of lines in a file"skipBlankLines": true
ignore lines made up purely of whitespace."skipComments": true
ignore lines containing just comments
code
Examples of incorrect code for this rule with a max value of 2
:
/*eslint max-lines: ["error", 2]*/
var a,
b,
c;
/*eslint max-lines: ["error", 2]*/
var a,
b,c;
/*eslint max-lines: ["error", 2]*/
// a comment
var a,
b,c;
Examples of correct code for this rule with a max value of 2
:
/*eslint max-lines: ["error", 2]*/
var a,
b, c;
/*eslint max-lines: ["error", 2]*/
var a, b, c;
/*eslint max-lines: ["error", 2]*/
// a comment
var a, b, c;
skipBlankLines
Examples of incorrect code for this rule with the { "skipBlankLines": true }
option:
/*eslint max-lines: ["error", {"max": 2, "skipBlankLines": true}]*/
var a,
b,
c;
Examples of correct code for this rule with the { "skipBlankLines": true }
option:
/*eslint max-lines: ["error", {"max": 2, "skipBlankLines": true}]*/
var a,
b, c;
skipComments
Examples of incorrect code for this rule with the { "skipComments": true }
option:
/*eslint max-lines: ["error", {"max": 2, "skipComments": true}]*/
// a comment
var a,
b,
c;
Examples of correct code for this rule with the { "skipComments": true }
option:
/*eslint max-lines: ["error", {"max": 2, "skipComments": true}]*/
// a comment
var a,
b, c;
When Not To Use It
You can turn this rule off if you are not concerned with the number of lines in your files.
Further reading
Related Rules
Compatibility
- JSCS: maximumNumberOfLines
Version
This rule was introduced in ESLint 2.12.0.