tsc removes comments preceding 'export = ...' unless extra newline follows the comment

[ulritech]

The tsc compiler with remove comments set to false (no --removeComments flag and/or "removeComments": false in tsconfig.json) performs unexpectedly based on whitespace characters surrounding comments before an export statement. For example,

/* @ngInject */
export = function($scope: any) {
    // A comment
    $scope.options = {};
}

Run the compiler:

$ tsc --module commonjs controller.ts

The compiler strips /* @ngInject */ but preserves // A comment

module.exports = function ($scope) {
    // A comment
    $scope.options = {};
};

However, *placing a new line after /* @ngInject / keeps it from being removed:

/* @ngInject */

export = function($scope: any) {
    // A comment
    $scope.options = {};
}

produces

/* @ngInject */
export = function($scope: any) {
    // A comment
    $scope.options = {};
}

Any idea why tsc is sensitive to such contextual whitespace?

$ tsc -v
message TS6029: Version 1.7.5