Properties retrieved via destructuring do not mark that property as being used

[tomdale]

TypeScript Version: 2.1.0-dev.20161003

Code

class Animal {
 constructor(private species: string) {
 }

 printSpecies() {
 let { species } = this;
 console.log(species);
 }
}

Expected behavior:
If I have the noUnusedLocals option enabled, the code should compile without warnings because the species property is being used.

Actual behavior:
If I have the noUnusedLocals option enabled, I receive:

src/index.ts(2,23): error TS6138: Property 'species' is declared but never used.

[grovesNL]

Sheetal Nandi (@sheetalkamat): Is this the same issue as the following:

class Test {
 private example: number = 1.0; // 'example' is declared but never used
 private constructor() {
 const { example } = this;
 console.warn(example);
 }
}

I hit this in 2.1.1 so I'm not sure if it's a different case.

[sheetalkamat]

Josh Groves (@grovesNL) I do not see error being reported when I used TypeScript@next

[loliver]

I'm seeing what I believe is this issue in the following class constructor:

static $inject = ['$window', '$location'];

private productCode: string;
private sourceCode: string;

private productData: any;

constructor(private $window: ng.IWindowService,
 private $location: ng.ILocationService) {
 this.productCode = $location.search().apptype;
 this.sourceCode = $location.search().sourcecode_1;
 this.productData = this.getProductData();
}

It is happening for $location if I use it to set properties directly in the constructor but if I create a function to do it then call that in the constructor it's fine eg:

static $inject = ['$window', '$location'];

private productCode: string;
private sourceCode: string;

private productData: any;

constructor(private $window: ng.IWindowService,
 private $location: ng.ILocationService) {
 this.setProductCodes();
 this.productData = this.getProductData();
}

private setProductCodes() {
 this.productCode = this.$location.search().apptype;
 this.sourceCode = this.$location.search().sourcecode_1;
}

I'm moving forward with the second set of code as it's better practice anyway but thought this may help people who find this issue on Google.

Hi Oliver Gassman (@loliver), in the first example you don't seem to ever access this.$location. In the second example you do (although you don't need to; you could pass location as a property to setProductCodes to avoid storing it on the object.)