devsite/node_modules/sucrase/dist/esm/util/shouldElideDefaultExport.js
2024-07-07 18:49:38 -07:00

39 lines
1.1 KiB
JavaScript

import {TokenType as tt} from "../parser/tokenizer/types";
/**
* Common method sharing code between CJS and ESM cases, since they're the same here.
*/
export default function shouldElideDefaultExport(
isTypeScriptTransformEnabled,
keepUnusedImports,
tokens,
declarationInfo,
) {
if (!isTypeScriptTransformEnabled || keepUnusedImports) {
return false;
}
const exportToken = tokens.currentToken();
if (exportToken.rhsEndIndex == null) {
throw new Error("Expected non-null rhsEndIndex on export token.");
}
// The export must be of the form `export default a` or `export default a;`.
const numTokens = exportToken.rhsEndIndex - tokens.currentIndex();
if (
numTokens !== 3 &&
!(numTokens === 4 && tokens.matches1AtIndex(exportToken.rhsEndIndex - 1, tt.semi))
) {
return false;
}
const identifierToken = tokens.tokenAtRelativeIndex(2);
if (identifierToken.type !== tt.name) {
return false;
}
const exportedName = tokens.identifierNameForToken(identifierToken);
return (
declarationInfo.typeDeclarations.has(exportedName) &&
!declarationInfo.valueDeclarations.has(exportedName)
);
}