Microsoft/TypeScript

.js error when module type is CommonJS and a variable name is exports

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#54,738 opened on Jun 22, 2023

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BugDomain: JS EmitHelp Wanted

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Description

Bug Report

🔎 CommonJS exports

🕗 5.1.3

⏯ Playground Link

Playground link with relevant code

💻 Code

export let a = 1;

function b(exports: any) {
    if (a == 1)
        return exports.a;
    else
        return exports.b;
}

🙁 Actual behavior

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.a = void 0;
exports.a = 1;
function b(exports) {
    if (exports.a == 1)
        return exports.a;
    else
        return exports.b;
}

🙂 Expected behavior

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.a = void 0;
exports.a = 1;
function b(exports_1) {
    if (exports.a == 1)
        return exports_1.a;
    else
        return exports_1.b;
}

Contributor guide

Research direction
Find the code in the TypeScript compiler that handles renaming of identifiers to avoid conflicts with the global 'exports' object in CommonJS modules. Check the emit phase.
Tech stack
typescript
Domain
compilers
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
TypeScript basics
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70