Modify rule S4124: Adapt to LaYC (#2692)

Co-authored-by: Yassin Kammoun <52890329+yassin-kammoun-sonarsource@users.noreply.github.com>

rules/S4124/javascript/rule.adoc

@@ -1,31 +1,42 @@
 == Why is this an issue?
 
-Declare a constructor inside an ``++interface++``, and you will get a simple method with the name "constructor". The same thing will happen if you create a ``++new++`` method inside the ``++interface++``: you'll get a simple method named "new".
+JavaScript and TypeScript classes may define a `constructor` method that is executed when a new instance is created. TypeScript allows interfaces that describe a static class object to define a `new()` method. Using these terms to name methods in other contexts can lead to confusion and make the code unclear and harder to understand.
+
+This rule reports when:
+
+* A class defines a method named `new`. The `new` keyword is used to create new instances of the class. If a method with the same name is defined, it can be unclear whether the method is intended to create new instances or perform some other action.
+* An interface defines a method named `constructor`. The constructor method is used to define the constructor function for a class that implements the interface. If a method with the same name is defined in the interface, it can be unclear whether the method is intended to define the constructor function or perform some other action.
 
 
-Instead, the intent was probably to specify that the type did not originate from a TypeScript file. In such cases, just use the ``++declare class++`` syntax.
+[source,javascript,diff-id=1,diff-type=noncompliant]
-
-
-=== Noncompliant code example
-
-[source,javascript]
 ----
-interface TypeDeclaredElsewhere {
+interface I {
-  someMethod(): number;
+  constructor(): void; // Noncompliant
-  new(b: boolean): TypeDeclaredElsewhere; // Noncompliant
+  new(): I;
-  constructor(b: boolean): void; // Noncompliant
+}
+
+declare class C {
+  constructor();
+  new(): C; // Noncompliant
 }
 ----
 
+Do not define methods named `constructor` on TypeScript interfaces. Similarly, avoid defining class methods called `new`.
 
-=== Compliant solution
+[source,javascript,diff-id=1,diff-type=compliant]
-
-[source,javascript]
 ----
-declare class TypeDeclaredElsewhere {
+interface I {
-  someMethod(): number;
+  new(): I;
-  constructor(b: boolean);
+}
+
+declare class C {
+  constructor();
 }
 ----
 
-
+== Resources
+=== Documentation
+* https://www.typescriptlang.org/docs/handbook/2/everyday-types.html#interfaces[TypeScript - Interfaces]
+* https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes[MDN - Classes]
+* https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes/constructor[MDN - `constructor`]
+* https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/new[MDN - `new` operator]