E0273: TypeScript namespaces are not allowed in JavaScript

TypeScript supports namespaces to describe objects. JavaScript does not support this syntax. It is a syntax error to use TypeScript's namespace keyword to create a namespace in JavaScript:

namespace goog {
  export class Chart {
    // ...
  }
}

To fix this error, create a variable with an object instead:

const goog = {};

goog.Chart = class Chart {
  // ...
};

Introduced in quick-lint-js version 2.8.0.

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