Microsoft/TypeScript
Voir sur GitHubAlias Binding incorrectly propagates through properties on ephemeral import
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#43 891 ouverte le 29 avr. 2021
BugDomain: BinderHelp Wanted
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Description
Bug Report
This is related to the [closed] issue #41628. We have some code that requires JSON (with "resolveJsonModule": true set in our tsconfig.json) and immediately accesses a string field (package version) on the returned JSON object, assigning it to a var/let variable. This produces the following error:
Cannot assign to 'version' because it is not a variable. ts(2539)
🔎 Search Terms
require json cannot assign let alias
🕗 Version & Regression Information
- This changed between versions 4.0 and 4.1
⏯ Playground Link
Playground link with relevant code
💻 Code
let version = require('./package.json').version;
version += "-debug";
🙁 Actual behavior
TypeScript reports the following error:
Cannot assign to 'version' because it is not a variable.
🙂 Expected behavior
We expect no error in this case. The version property on the object returned by the require function should not be considered an alias, but a simple string.
One workaround is, of course, to use the //ts-ignore hammer. Another is to do something like the following:
const pkg = require('./package.json');
let version = pkg.version;
version += "-debug";