swc/crates/swc_ecma_parser/tests/tsc/readonlyConstructorAssignment.ts

// Tests that readonly parameter properties behave like regular readonly properties

class A {
    constructor(readonly x: number) {
        this.x = 0;
    }
}

class B extends A {
    constructor(x: number) {
        super(x);
        // Fails, x is readonly
        this.x = 1;
    }
}

class C extends A {
    // This is the usual behavior of readonly properties:
    // if one is redeclared in a base class, then it can be assigned to.
    constructor(readonly x: number) {
        super(x);
        this.x = 1;
    }
}

class D {
    constructor(private readonly x: number) {
        this.x = 0;
    }
}

// Fails, can't redeclare readonly property
class E extends D {
    constructor(readonly x: number) {
        super(x);
        this.x = 1;
    }
}