16f6c0aecf
Inline adoc files when they are included exactly once. Also fix language tags because this inlining gives us better information on what language the code is written in.
72 lines
1.4 KiB
Plaintext
72 lines
1.4 KiB
Plaintext
== Why is this an issue?
|
|
|
|
Union types represent a value that can be one of the several types. When a union type is used for a function parameter and it is accepting too many types, it may indicate the function is having too many responsibilities. Sometimes it's worth creating a type alias for this union type. In all cases, the code should be reviewed and refactored to make it more maintainable.
|
|
|
|
|
|
=== Noncompliant code example
|
|
|
|
With the default threshold of 3:
|
|
|
|
[source,javascript]
|
|
----
|
|
let x: MyType1 | MyType2 | MyType3 | MyType4; // Noncompliant
|
|
|
|
function foo(p1: string, p2: MyType1 | MyType2 | MyType3 | MyType4) { // Noncompliant
|
|
// ...
|
|
}
|
|
----
|
|
|
|
|
|
=== Compliant solution
|
|
|
|
[source,javascript]
|
|
----
|
|
type MyUnionType = MyType1 | MyType2 | MyType3 | MyType4; // Compliant, "type" statements are ignored
|
|
let x: MyUnionType;
|
|
|
|
function foo(value: string, padding: MyUnionType) {
|
|
// ...
|
|
}
|
|
----
|
|
|
|
|
|
=== Exceptions
|
|
|
|
This rule ignores union types part of ``++type++`` statement:
|
|
|
|
[source,javascript]
|
|
----
|
|
type MyUnionType = MyType1 | MyType2 | MyType3 | MyType4;
|
|
----
|
|
|
|
ifdef::env-github,rspecator-view[]
|
|
|
|
'''
|
|
== Implementation Specification
|
|
(visible only on this page)
|
|
|
|
=== Message
|
|
|
|
Refactor this union type to have less than X elements.
|
|
|
|
|
|
=== Parameters
|
|
|
|
.max
|
|
****
|
|
|
|
----
|
|
3
|
|
----
|
|
|
|
Maximum elements authorized in a union type definition.
|
|
****
|
|
|
|
|
|
=== Highlighting
|
|
|
|
All the elements of the union type
|
|
|
|
|
|
endif::env-github,rspecator-view[]
|