Function has a complexity of 7. Open
var AppError = function(err, customMsg, log, overrideMsg) {
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Limit Cyclomatic Complexity (complexity)
Cyclomatic complexity measures the number of linearly independent paths through a program's source code. This rule allows setting a cyclomatic complexity threshold.
function a(x) {
if (true) {
return x; // 1st path
} else if (false) {
return x+1; // 2nd path
} else {
return 4; // 3rd path
}
}
Rule Details
This rule is aimed at reducing code complexity by capping the amount of cyclomatic complexity allowed in a program. As such, it will warn when the cyclomatic complexity crosses the configured threshold (default is 20
).
Examples of incorrect code for a maximum of 2:
/*eslint complexity: ["error", 2]*/
function a(x) {
if (true) {
return x;
} else if (false) {
return x+1;
} else {
return 4; // 3rd path
}
}
Examples of correct code for a maximum of 2:
/*eslint complexity: ["error", 2]*/
function a(x) {
if (true) {
return x;
} else {
return 4;
}
}
Options
Optionally, you may specify a max
object property:
"complexity": ["error", 2]
is equivalent to
"complexity": ["error", { "max": 2 }]
Deprecated: the object property maximum
is deprecated. Please use the property max
instead.
When Not To Use It
If you can't determine an appropriate complexity limit for your code, then it's best to disable this rule.
Further Reading
Related Rules
- [max-depth](max-depth.md)
- [max-len](max-len.md)
- [max-nested-callbacks](max-nested-callbacks.md)
- [max-params](max-params.md)
- [max-statements](max-statements.md) Source: http://eslint.org/docs/rules/
Function AppError
has a Cognitive Complexity of 9 (exceeds 5 allowed). Consider refactoring. Open
var AppError = function(err, customMsg, log, overrideMsg) {
if (!err) {
throw new ReferenceError('Invalid error object.');
}
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Cognitive Complexity
Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.
A method's cognitive complexity is based on a few simple rules:
- Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
- Code is considered more complex for each "break in the linear flow of the code"
- Code is considered more complex when "flow breaking structures are nested"
Further reading
Use path.join() or path.resolve() instead of + to create paths. Open
var _appConfig = require(__dirname + '/../../config.js');
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Disallow string concatenation when using __dirname
and __filename
(no-path-concat)
In Node.js, the __dirname
and __filename
global variables contain the directory path and the file path of the currently executing script file, respectively. Sometimes, developers try to use these variables to create paths to other files, such as:
var fullPath = __dirname + "/foo.js";
However, there are a few problems with this. First, you can't be sure what type of system the script is running on. Node.js can be run on any computer, including Windows, which uses a different path separator. It's very easy, therefore, to create an invalid path using string concatenation and assuming Unix-style separators. There's also the possibility of having double separators, or otherwise ending up with an invalid path.
In order to avoid any confusion as to how to create the correct path, Node.js provides the path
module. This module uses system-specific information to always return the correct value. So you can rewrite the previous example as:
var fullPath = path.join(__dirname, "foo.js");
This example doesn't need to include separators as path.join()
will do it in the most appropriate manner. Alternately, you can use path.resolve()
to retrieve the fully-qualified path:
var fullPath = path.resolve(__dirname, "foo.js");
Both path.join()
and path.resolve()
are suitable replacements for string concatenation wherever file or directory paths are being created.
Rule Details
This rule aims to prevent string concatenation of directory paths in Node.js
Examples of incorrect code for this rule:
/*eslint no-path-concat: "error"*/
var fullPath = __dirname + "/foo.js";
var fullPath = __filename + "/foo.js";
Examples of correct code for this rule:
/*eslint no-path-concat: "error"*/
var fullPath = dirname + "/foo.js";
When Not To Use It
If you want to allow string concatenation of path names. Source: http://eslint.org/docs/rules/
TODO found Open
// TODO Write code to display error.
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