removeComments compiler option seems to be ignored when using typescript 1.5.0-beta

[milkshakeuk]

Specifying the argument ($ tsc --removeComments) or option in (tsconfig.json) for removing comments is not honoured.

Normal comments are removed, but special comments, like references and amd dependencies, are preserved.

/// <reference path="../Interfaces/IView" />
/// <reference path="./BaseView" />
/// <amd-dependency path="/js/libs/hgn.js!app/templates/home" name="compiler"/>

I don't know if this new behaviour is intended but this wasn't the case in the previous release and I wouldn't expect these special comments to be required in the output files.

[NickHeiner]

Additionally, I'm seeing multiline comments not getting removed:

index.ts

'use strict';

// single line comment
console.log('hi');

/**
 * js-doc style comment
 */
function foo() {
    /*

        multi line
        comment
    */

    return 42;
}

tsconfig.json

{
    "compilerOptions": {
        "removeComments": true
    }
}

λ tsc -v
message TS6029: Version 1.5.3
λ tsc -p .

The output js:

'use strict';
console.log('hi');
function foo() {
    /*

        multi line
        comment
    */
    return 42;
}

[NickHeiner]

Another (possibly related) bug: multiline comments are always removed if they are the only thing in thing in the body of a function:

tsconfig.json

{
    "compilerOptions": {
        "module": "commonjs",
        "removeComments": false
    }
}

index.ts

function foo() { /*
    This multiline string will only work
    if the TS compiler does not remove comments.
*/ }

λ tsc -v
message TS6029: Version 1.5.3
λ tsc -p .

Generated index.js

function foo() {
}

If I add a statement to the body of foo, then I do not see this problem.

This breaks code that uses the multiline module.

[NickHeiner]

And I know that TS offers multiline strings via template strings, but here's another use case:

index.ts

declare var angular: any;

angular.module('app').factory('myService', /* @ngInject */ function foo($scope, filter) {

});

tsconfig.json

{
    "compilerOptions": {
        "removeComments": false
    }
}

λ tsc -v
message TS6029: Version 1.5.3
λ tsc -p .

Generated index.js

angular.module('app').factory('myService', function foo($scope, filter) {
});

The /* @ngInject */ comment needs to be there so ng-annotate can annotate the Angular dependency injection function.

[mhegazy]

@NickHeiner the last issue seems to be a different one. I have filed #3844 to track it.

[NickHeiner]

Awesome, thanks!

[DickvdBrink]

@yuit, Can I take this one?

[yuit]

@DickvdBrink sure. Thanks!
Edit: I fix the original issue on removing triple-slash comment (PR is coming out soon). However, I haven't look at other issues in the comments which seem to require separate fix from the original one. If you could take a look on that, it will be great!

[yuit]

An update on this issue, @CyrusNajmabadi explains /// comment is a special directive in our language not just a plain comment and thus we should keep it. I have opened an issue regarding fine-tuning removing of "comments" issue #3878 that we can discuss further.

Thus, we will keep currently behavior of the /// comments (i.e. we will keep /// comments) However, following case is a bug that we will have to fix (when /// comments are not at the top of the file.)

var x = 10
/// <reference path ="blah.ts" />