estree to babel

convert estree ast to babel

coderaiser
34
7
JavaScript

Estree-to-babel NPM version Build Status Coverage Status

Convert ESTree-compatible JavaScript AST to Babel AST.

To use parsers like:

With babel tools like:

The thing is @babel/parser has a little differences with estree standard:

  • Property of ObjectExpression and ObjectPattern called ObjectProperty;
  • FunctionExpression of a Property located in ObjectMethod node;
  • File node;
  • StringLiteral, NumericLiteral, NullLiteral, RegExpLiteral, BooleanLiteral instead of Literal;
  • ClassMethod instead of MethodDefinition;
  • ClassPrivateMethod;
  • ClassPrivateName stores name as Identifier in id field;
  • ClassPrivateProperty instead of FieldDefinition;
  • OptionalMemberExpression and OptionalCallExpression instead of ChainExpression;
  • ImportDeclaration and ExportNamedDeclaration has attributes;
  • JSXText has extra field;
  • etc…

Also @babel/parser has differences with typescript-estree:

  • ClassPrivateProperty instead of PropertyDefinition when key.type=PrivateName;
  • ClasseProperty instead of PropertyDefinition when key.type=Identifier;
  • PrivateName instead of PrivateIdentifier;
  • TSQualifiedName instead of MemberExpression in TSInterfaceHeritage;
  • TSDeclaredMethod with abstract=true instead of TSAbstractMethodDefinition;
  • etc…

estree-to-babel aims to smooth this differences.

Install

npm i estree-to-babel

Example

const cherow = require('cherow');
const toBabel = require('estree-to-babel');
const traverse = require('@babel/traverse').default;

const ast = toBabel(cherow.parse(`
    const f = ({a}) => a;
`));

traverse({
    ObjectProperty(path) {
        console.log(path.value.name);
        // output
        'a';
    },
});

License

MIT