Registry / serialization / babel-type-scopes

babel-type-scopes

library1.1.0jsnpmunverified

Utility functions for looking up and working with Flow and TypeScript type scopes in Babel. Version 1.1.0 provides four main functions: isTypeScope, getClosestTypeScopePath, getOwnTypeBindings, and getTypeBinding. These helpers identify whether a Babel path creates a type scope, find the nearest ancestor type scope, retrieve type bindings defined in the current scope, and search for type bindings up the scope chain. The package supports both Flow and TypeScript, and is intended for Babel plugin or tool authors. It is lightweight with no production dependencies. Released in 2018, the library is stable but sees infrequent updates. Similar functionality exists in @babel/traverse, but this package provides more targeted scope inspection.

serialization

npm install babel-type-scopes

github ↗package ↗

INSTALL

IMPORT

SIG · BABEL-TYPE-SCOPES

babel-type-scopes

serializationjavascriptv1.1.0

Install

—

Import

—

Disk

—

Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

isTypeScope

✓ import { isTypeScope } from 'babel-type-scopes'

✗ const isTypeScope = require('babel-type-scopes').isTypeScope

Correct named import. The package is ESM-only; require will not work without transpilation.

getClosestTypeScopePath

✓ import { getClosestTypeScopePath } from 'babel-type-scopes'

✗ import getClosestTypeScopePath from 'babel-type-scopes'

Named export, not default export.

getTypeBinding

✓ import { getTypeBinding } from 'babel-type-scopes'

✗ const { getTypeBinding } = require('babel-type-scopes')

CommonJS require with destructuring is possible if you use a bundler, but ESM import is recommended.

Parses TypeScript code, traverses AST, and demonstrates each exported function on a type alias.

import { isTypeScope, getClosestTypeScopePath, getOwnTypeBindings, getTypeBinding } from 'babel-type-scopes'; import { parse } from '@babel/parser'; import traverse from '@babel/traverse'; const code = `type Foo = string; let x: Foo = 'hello';`; const ast = parse(code, { plugins: ['typescript'] }); traverse(ast, { TSTypeAliasDeclaration(path) { console.log(isTypeScope(path)); // true const scopePath = getClosestTypeScopePath(path); console.log(scopePath.node.type); // TSTypeAliasDeclaration const bindings = getOwnTypeBindings(scopePath); console.log(Object.keys(bindings)); // ['Foo'] const binding = getTypeBinding(path, 'Foo'); console.log(binding.kind); // 'declaration' } });

Debug

Known issues

gotchaThe package only considers type scopes (type declarations, interface, etc.). Regular variable scopes are not covered.

fix

Use @babel/traverse's getBinding for non-type bindings.

affects: <=1.1.0

gotchagetClosestTypeScopePath may return the current path if it is a type scope, which may be unexpected.

fix

Check if the returned path is the same as the input; if so, the path itself is a type scope.

affects: all

gotchagetTypeBinding searches only type scopes; it does not look up regular bindings. This may cause confusion if a binding is declared with 'let' or 'const'.

fix

Use getTypeBinding only for type-level bindings (types, interfaces). For value bindings, use @babel/traverse's scope.getBinding.

affects: all

Errors

Common errors & fixes

Cannot find module 'babel-type-scopes'

Package not installed or missing from node_modules.

fix

Run 'npm install babel-type-scopes' or 'yarn add babel-type-scopes'.

TypeError: isTypeScope is not a function

Incorrect import syntax (e.g., default import instead of named import).

fix

Use 'import { isTypeScope } from 'babel-type-scopes';'

TypeError: Cannot read property 'kind' of undefined

No type binding found in the scope chain for the given name.

fix

Ensure the name exists as a type binding; consider checking getOwnTypeBindings first.

Upgrade

Version history

1.1.0latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

19 hits · last 30 days

node

Amazon

OpenAI (training)

Resources

githubhttps://github.com/babel-utils/babel-type-scopes ↗

packagehttps://www.npmjs.com/package/babel-type-scopes ↗