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TypeError: Cannot redefine property: default

See original GitHub issue

Using Node 12.16.1, TypeScript 3.8.3, and tslib 1.12.0 I’m seeing this error:

/Users/phensley/dev/cldr-engine/node_modules/tslib/tslib.js:237
        Object.defineProperty(o, "default", { enumerable: true, value: v });
               ^
TypeError: Cannot redefine property: default
    at Function.defineProperty (<anonymous>)
    at /Users/phensley/dev/cldr-engine/node_modules/tslib/tslib.js:237:16
    at Object.__importStar (/Users/phensley/dev/cldr-engine/node_modules/tslib/tslib.js:246:9)
    at Object.<anonymous> (/Users/phensley/dev/cldr-engine/packages/cldr-compiler/lib/cli/compiler/index.js:4:21)

Occurs when __importStar is called: import * as yargs from 'yargs';

Transpiled to: var yargs = tslib_1.__importStar(require("yargs"));

Issue Analytics

State:
Created 3 years ago
Reactions:12
Comments:10 (3 by maintainers)

Top GitHub Comments

23reactions

kamilmysliwieccommented, May 13, 2020

Ahh yeah, tslib 1.12.0 expects some emit concessions provided by TS 3.9 (namely hoisted export names) without which some stuff won’t work as expected. We probably need to adjust our messaging/versioning.

@weswigham if there’s any breaking change introduced, it would be nice if a new release could be published with a major version update. This minor release broke a lot of packages that the community heavily depends on.

@DanielRosenwasser Please, consider reverting this release till the reasonable alternative is found.

13reactions

weswighamcommented, May 13, 2020

Howdy everyone - if you’re still working with TS <= 3.8, the new tslib version 1.13.0 should fix the issues you were having; it does not support live bindings, but should continue to work with both older and newer emit without a runtime error. The newly published tslib 2.0.0 has the contents of the former 1.12.0, and provides support for live bindings alongside TS 3.9+ emit; so nobody should be installing it by accident in existing projects anymore~ Sorry for the inconvenience everyone ❤️

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