Closed
Description
TLDR: TypeScript does not generate JS code for exported variables when they are not used in current compilation scope, only the declarations (.d.ts)
Example
source files
// a.ts
import b = require("b");
b.c.say();
// b.ts
export import c = require("c");
// c.ts
export function say() {
console.log("Hello World!");
}
Success scenario. We are using a.ts directly. tsc a.ts --module commonjs
generated files
// a.js
var b = require("b");
b.c.say();
// b.js
var c = require("c");
exports.c = c;
// c.js
function say() {
console.log("Hello World!");
}
exports.say = say;
Failure scenario. Imagine if a.ts is placed into another project and uses b.ts as external dependency. In that case we need to compile b.ts with declarations for it. tsc b.ts --module commonjs --declaration
// c.js
function say() {
console.log("Hello World!");
}
exports.say = say;
// c.d.ts
export declare function say(): void;
// b.d.ts
export import c = require("c");
// b.js IT IS EMPTY!
First, this behavior is strongly inconsistent since generated declarations contains definitions for code that does not exist in generated JS.
Also, the fact that the JS code does not get generated at all is a blocker for our current use cases.
We need this fixed as soon as possible.