d3cfe19d7e
Co-authored-by: Marco Borgeaud <89914223+marco-antognini-sonarsource@users.noreply.github.com>
68 lines
1.7 KiB
Plaintext
68 lines
1.7 KiB
Plaintext
include::../why.adoc[]
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=== Exceptions
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The rule ignores
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* Initializations to `-1`, `0`, `1`, `undefined`, `[]`, `{}`, `true`, `false` and `""`.
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* Variables that start with an underscore (e.g. ``++_unused++``) are ignored.
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* Assignment of `null` is ignored because it is sometimes used to help garbage collection
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* Increment and decrement expressions are ignored because they are often used idiomatically instead of `x+1`
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* This rule also ignores variables declared with object destructuring using rest syntax (used to exclude some properties from object)
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[source,javascript]
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----
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let {a, b, ...rest} = obj; // 'a' and 'b' are compliant
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doSomething(rest);
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let [x1, x2, x3] = arr; // 'x1' is noncompliant, as omitting syntax can be used: "let [, x2, x3] = arr;"
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doSomething(x2, x3);
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----
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include::../howtofixit.adoc[]
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=== Code examples
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==== Noncompliant code example
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[source,javascript,diff-id=1,diff-type=noncompliant]
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----
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function foo(y) {
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let x = 100; // Noncompliant: dead store
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x = 150; // Noncompliant: dead store
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x = 200;
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return x + y;
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}
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----
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==== Compliant solution
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[source,javascript,diff-id=1,diff-type=compliant]
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----
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function foo(y) {
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let x = 200; // Compliant: no unnecessary assignment
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return x + y;
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}
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----
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include::../see.adoc[]
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=== Related rules
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* S1763 - All code should be reachable
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* S2589 - Boolean expressions should not be gratuitous
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* S3516 - Function returns should not be invariant
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* S3626 - Jump statements should not be redundant
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ifdef::env-github,rspecator-view[]
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'''
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== Implementation Specification
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(visible only on this page)
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include::../message.adoc[]
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include::../comments-and-links.adoc[]
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endif::env-github,rspecator-view[]
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