babel-types
Advanced tools
The babel-types package is a part of the Babel compiler ecosystem. It provides builders, validators, and conversion utilities for the various types of nodes in the Abstract Syntax Tree (AST) used by Babel. This package is essential for manipulating the AST generated or consumed by Babel, allowing for custom transformations and analysis of JavaScript code.
AST Node Builders
Builders are functions that help in creating AST nodes. This example demonstrates creating a binary expression node that represents the multiplication of two identifiers, 'a' and 'b'.
const t = require('babel-types');
const binaryExpression = t.binaryExpression('*', t.identifier('a'), t.identifier('b'));AST Node Validators
Validators are functions that check if a node is of a certain type or meets certain criteria. In this example, the validator checks if the node is an identifier with the name 'a'.
const t = require('babel-types');
const isValid = t.isIdentifier(t.identifier('a'), { name: 'a' });Type Conversion Utilities
Conversion utilities allow for the transformation of one type of node into another. This example shows converting a numeric literal into a string literal.
const t = require('babel-types');
const numericLiteral = t.numericLiteral(5);
const asStringLiteral = t.stringLiteral(`${numericLiteral.value}`);This is the newer version of babel-types, rebranded and scoped under the Babel organization. It offers the same functionalities but is more actively maintained and includes updates for the latest JavaScript features.
Recast provides AST manipulation capabilities with a focus on preserving the original formatting as much as possible. While babel-types is more about creating and validating AST nodes, recast is geared towards parsing and reprinting code with minimal changes.
Acorn is a fast, small JavaScript parser that generates an AST. While it doesn't offer manipulation utilities like babel-types, it's often used in conjunction with other tools for analysis and transformation tasks.
This module contains methods for building ASTs manually and for checking the types of AST nodes.
npm install --save-dev babel-types
t.anyTypeAnnotation()
See also t.isAnyTypeAnnotation(node, opts) and t.assertAnyTypeAnnotation(node, opts).
Aliases: Flow, FlowBaseAnnotation
t.arrayExpression(elements)
See also t.isArrayExpression(node, opts) and t.assertArrayExpression(node, opts).
Aliases: Expression
elements: Array<null | Expression | SpreadElement> (default: [])t.arrayPattern(elements, typeAnnotation)
See also t.isArrayPattern(node, opts) and t.assertArrayPattern(node, opts).
Aliases: Pattern, LVal
elements: Array<Identifier | Pattern | RestElement> (required)typeAnnotation (required)decorators: Array<Decorator> (default: null)t.arrayTypeAnnotation(elementType)
See also t.isArrayTypeAnnotation(node, opts) and t.assertArrayTypeAnnotation(node, opts).
Aliases: Flow
elementType (required)t.arrowFunctionExpression(params, body, async)
See also t.isArrowFunctionExpression(node, opts) and t.assertArrowFunctionExpression(node, opts).
Aliases: Scopable, Function, BlockParent, FunctionParent, Expression, Pureish
params: Array<LVal> (required)body: BlockStatement | Expression (required)async: boolean (default: false)returnType (default: null)typeParameters (default: null)t.assignmentExpression(operator, left, right)
See also t.isAssignmentExpression(node, opts) and t.assertAssignmentExpression(node, opts).
Aliases: Expression
operator: string (required)left: LVal (required)right: Expression (required)t.assignmentPattern(left, right)
See also t.isAssignmentPattern(node, opts) and t.assertAssignmentPattern(node, opts).
Aliases: Pattern, LVal
left: Identifier (required)right: Expression (required)decorators: Array<Decorator> (default: null)t.awaitExpression(argument)
See also t.isAwaitExpression(node, opts) and t.assertAwaitExpression(node, opts).
Aliases: Expression, Terminatorless
argument: Expression (required)t.binaryExpression(operator, left, right)
See also t.isBinaryExpression(node, opts) and t.assertBinaryExpression(node, opts).
Aliases: Binary, Expression
operator: '+' | '-' | '/' | '%' | '*' | '**' | '&' | '|' | '>>' | '>>>' | '<<' | '^' | '==' | '===' | '!=' | '!==' | 'in' | 'instanceof' | '>' | '<' | '>=' | '<=' (required)left: Expression (required)right: Expression (required)t.bindExpression(object, callee)
See also t.isBindExpression(node, opts) and t.assertBindExpression(node, opts).
Aliases: Expression
object (required)callee (required)t.blockStatement(body, directives)
See also t.isBlockStatement(node, opts) and t.assertBlockStatement(node, opts).
Aliases: Scopable, BlockParent, Block, Statement
body: Array<Statement> (required)directives: Array<Directive> (default: [])t.booleanLiteral(value)
See also t.isBooleanLiteral(node, opts) and t.assertBooleanLiteral(node, opts).
Aliases: Expression, Pureish, Literal, Immutable
value: boolean (required)t.booleanLiteralTypeAnnotation()
See also t.isBooleanLiteralTypeAnnotation(node, opts) and t.assertBooleanLiteralTypeAnnotation(node, opts).
Aliases: Flow
t.booleanTypeAnnotation()
See also t.isBooleanTypeAnnotation(node, opts) and t.assertBooleanTypeAnnotation(node, opts).
Aliases: Flow, FlowBaseAnnotation
t.breakStatement(label)
See also t.isBreakStatement(node, opts) and t.assertBreakStatement(node, opts).
Aliases: Statement, Terminatorless, CompletionStatement
label: Identifier (default: null)t.callExpression(callee, arguments)
See also t.isCallExpression(node, opts) and t.assertCallExpression(node, opts).
Aliases: Expression
callee: Expression (required)arguments: Array<Expression | SpreadElement> (required)t.catchClause(param, body)
See also t.isCatchClause(node, opts) and t.assertCatchClause(node, opts).
Aliases: Scopable
param: Identifier (required)body: BlockStatement (required)t.classBody(body)
See also t.isClassBody(node, opts) and t.assertClassBody(node, opts).
body: Array<ClassMethod | ClassProperty> (required)t.classDeclaration(id, superClass, body, decorators)
See also t.isClassDeclaration(node, opts) and t.assertClassDeclaration(node, opts).
Aliases: Scopable, Class, Statement, Declaration, Pureish
id: Identifier (required)superClass: Expression (default: null)body: ClassBody (required)decorators: Array<Decorator> (required)implements (default: null)mixins (default: null)superTypeParameters (default: null)typeParameters (default: null)t.classExpression(id, superClass, body, decorators)
See also t.isClassExpression(node, opts) and t.assertClassExpression(node, opts).
Aliases: Scopable, Class, Expression, Pureish
id: Identifier (default: null)superClass: Expression (default: null)body: ClassBody (required)decorators: Array<Decorator> (required)implements (default: null)mixins (default: null)superTypeParameters (default: null)typeParameters (default: null)t.classImplements(id, typeParameters)
See also t.isClassImplements(node, opts) and t.assertClassImplements(node, opts).
Aliases: Flow
id (required)typeParameters (required)t.classMethod(kind, key, params, body, computed, static)
See also t.isClassMethod(node, opts) and t.assertClassMethod(node, opts).
Aliases: Function, Scopable, BlockParent, FunctionParent, Method
kind: "get" | "set" | "method" | "constructor" (default: 'method')keyif computed then Expression else Identifier | Literal (required)params: Array<LVal> (required)body: BlockStatement (required)computed: boolean (default: false)static: boolean (default: false)async: boolean (default: false)decorators (default: null)generator: boolean (default: false)returnType (default: null)typeParameters (default: null)t.classProperty(key, value, typeAnnotation, decorators, computed)
See also t.isClassProperty(node, opts) and t.assertClassProperty(node, opts).
Aliases: Property
key (required)value (required)typeAnnotation (required)decorators (required)computed: boolean (default: false)t.conditionalExpression(test, consequent, alternate)
See also t.isConditionalExpression(node, opts) and t.assertConditionalExpression(node, opts).
Aliases: Expression, Conditional
test: Expression (required)consequent: Expression (required)alternate: Expression (required)t.continueStatement(label)
See also t.isContinueStatement(node, opts) and t.assertContinueStatement(node, opts).
Aliases: Statement, Terminatorless, CompletionStatement
label: Identifier (default: null)t.debuggerStatement()
See also t.isDebuggerStatement(node, opts) and t.assertDebuggerStatement(node, opts).
Aliases: Statement
t.declareClass(id, typeParameters, extends, body)
See also t.isDeclareClass(node, opts) and t.assertDeclareClass(node, opts).
Aliases: Flow, FlowDeclaration, Statement, Declaration
id (required)typeParameters (required)extends (required)body (required)t.declareExportDeclaration(declaration, specifiers, source)
See also t.isDeclareExportDeclaration(node, opts) and t.assertDeclareExportDeclaration(node, opts).
Aliases: Flow, FlowDeclaration, Statement, Declaration
declaration (required)specifiers (required)source (required)t.declareFunction(id)
See also t.isDeclareFunction(node, opts) and t.assertDeclareFunction(node, opts).
Aliases: Flow, FlowDeclaration, Statement, Declaration
id (required)t.declareInterface(id, typeParameters, extends, body)
See also t.isDeclareInterface(node, opts) and t.assertDeclareInterface(node, opts).
Aliases: Flow, FlowDeclaration, Statement, Declaration
id (required)typeParameters (required)extends (required)body (required)t.declareModule(id, body)
See also t.isDeclareModule(node, opts) and t.assertDeclareModule(node, opts).
Aliases: Flow, FlowDeclaration, Statement, Declaration
id (required)body (required)t.declareModuleExports(typeAnnotation)
See also t.isDeclareModuleExports(node, opts) and t.assertDeclareModuleExports(node, opts).
Aliases: Flow, FlowDeclaration, Statement, Declaration
typeAnnotation (required)t.declareOpaqueType(id, typeParameters, supertype)
See also t.isDeclareOpaqueType(node, opts) and t.assertDeclareOpaqueType(node, opts).
Aliases: Flow, FlowDeclaration, Statement, Declaration
id (required)typeParameters (required)supertype (required)t.declareTypeAlias(id, typeParameters, right)
See also t.isDeclareTypeAlias(node, opts) and t.assertDeclareTypeAlias(node, opts).
Aliases: Flow, FlowDeclaration, Statement, Declaration
id (required)typeParameters (required)right (required)t.declareVariable(id)
See also t.isDeclareVariable(node, opts) and t.assertDeclareVariable(node, opts).
Aliases: Flow, FlowDeclaration, Statement, Declaration
id (required)t.decorator(expression)
See also t.isDecorator(node, opts) and t.assertDecorator(node, opts).
expression: Expression (required)t.directive(value)
See also t.isDirective(node, opts) and t.assertDirective(node, opts).
value: DirectiveLiteral (required)t.directiveLiteral(value)
See also t.isDirectiveLiteral(node, opts) and t.assertDirectiveLiteral(node, opts).
value: string (required)t.doExpression(body)
See also t.isDoExpression(node, opts) and t.assertDoExpression(node, opts).
Aliases: Expression
body: BlockStatement (required)t.doWhileStatement(test, body)
See also t.isDoWhileStatement(node, opts) and t.assertDoWhileStatement(node, opts).
Aliases: Statement, BlockParent, Loop, While, Scopable
test: Expression (required)body: Statement (required)t.emptyStatement()
See also t.isEmptyStatement(node, opts) and t.assertEmptyStatement(node, opts).
Aliases: Statement
t.emptyTypeAnnotation()
See also t.isEmptyTypeAnnotation(node, opts) and t.assertEmptyTypeAnnotation(node, opts).
Aliases: Flow, FlowBaseAnnotation
t.existentialTypeParam()
See also t.isExistentialTypeParam(node, opts) and t.assertExistentialTypeParam(node, opts).
Aliases: Flow
t.exportAllDeclaration(source)
See also t.isExportAllDeclaration(node, opts) and t.assertExportAllDeclaration(node, opts).
Aliases: Statement, Declaration, ModuleDeclaration, ExportDeclaration
source: StringLiteral (required)t.exportDefaultDeclaration(declaration)
See also t.isExportDefaultDeclaration(node, opts) and t.assertExportDefaultDeclaration(node, opts).
Aliases: Statement, Declaration, ModuleDeclaration, ExportDeclaration
declaration: FunctionDeclaration | ClassDeclaration | Expression (required)t.exportDefaultSpecifier(exported)
See also t.isExportDefaultSpecifier(node, opts) and t.assertExportDefaultSpecifier(node, opts).
Aliases: ModuleSpecifier
exported: Identifier (required)t.exportNamedDeclaration(declaration, specifiers, source)
See also t.isExportNamedDeclaration(node, opts) and t.assertExportNamedDeclaration(node, opts).
Aliases: Statement, Declaration, ModuleDeclaration, ExportDeclaration
declaration: Declaration (default: null)specifiers: Array<ExportSpecifier> (required)source: StringLiteral (default: null)t.exportNamespaceSpecifier(exported)
See also t.isExportNamespaceSpecifier(node, opts) and t.assertExportNamespaceSpecifier(node, opts).
Aliases: ModuleSpecifier
exported: Identifier (required)t.exportSpecifier(local, exported)
See also t.isExportSpecifier(node, opts) and t.assertExportSpecifier(node, opts).
Aliases: ModuleSpecifier
local: Identifier (required)exported: Identifier (required)t.expressionStatement(expression)
See also t.isExpressionStatement(node, opts) and t.assertExpressionStatement(node, opts).
Aliases: Statement, ExpressionWrapper
expression: Expression (required)t.file(program, comments, tokens)
See also t.isFile(node, opts) and t.assertFile(node, opts).
program: Program (required)comments (required)tokens (required)t.forAwaitStatement(left, right, body)
See also t.isForAwaitStatement(node, opts) and t.assertForAwaitStatement(node, opts).
Aliases: Scopable, Statement, For, BlockParent, Loop, ForXStatement
left: VariableDeclaration | LVal (required)right: Expression (required)body: Statement (required)t.forInStatement(left, right, body)
See also t.isForInStatement(node, opts) and t.assertForInStatement(node, opts).
Aliases: Scopable, Statement, For, BlockParent, Loop, ForXStatement
left: VariableDeclaration | LVal (required)right: Expression (required)body: Statement (required)t.forOfStatement(left, right, body)
See also t.isForOfStatement(node, opts) and t.assertForOfStatement(node, opts).
Aliases: Scopable, Statement, For, BlockParent, Loop, ForXStatement
left: VariableDeclaration | LVal (required)right: Expression (required)body: Statement (required)t.forStatement(init, test, update, body)
See also t.isForStatement(node, opts) and t.assertForStatement(node, opts).
Aliases: Scopable, Statement, For, BlockParent, Loop
init: VariableDeclaration | Expression (default: null)test: Expression (default: null)update: Expression (default: null)body: Statement (required)t.functionDeclaration(id, params, body, generator, async)
See also t.isFunctionDeclaration(node, opts) and t.assertFunctionDeclaration(node, opts).
Aliases: Scopable, Function, BlockParent, FunctionParent, Statement, Pureish, Declaration
id: Identifier (required)params: Array<LVal> (required)body: BlockStatement (required)generator: boolean (default: false)async: boolean (default: false)returnType (default: null)typeParameters (default: null)t.functionExpression(id, params, body, generator, async)
See also t.isFunctionExpression(node, opts) and t.assertFunctionExpression(node, opts).
Aliases: Scopable, Function, BlockParent, FunctionParent, Expression, Pureish
id: Identifier (default: null)params: Array<LVal> (required)body: BlockStatement (required)generator: boolean (default: false)async: boolean (default: false)returnType (default: null)typeParameters (default: null)t.functionTypeAnnotation(typeParameters, params, rest, returnType)
See also t.isFunctionTypeAnnotation(node, opts) and t.assertFunctionTypeAnnotation(node, opts).
Aliases: Flow
typeParameters (required)params (required)rest (required)returnType (required)t.functionTypeParam(name, typeAnnotation)
See also t.isFunctionTypeParam(node, opts) and t.assertFunctionTypeParam(node, opts).
Aliases: Flow
name (required)typeAnnotation (required)t.genericTypeAnnotation(id, typeParameters)
See also t.isGenericTypeAnnotation(node, opts) and t.assertGenericTypeAnnotation(node, opts).
Aliases: Flow
id (required)typeParameters (required)t.identifier(name)
See also t.isIdentifier(node, opts) and t.assertIdentifier(node, opts).
Aliases: Expression, LVal
name``string (required)decorators: Array<Decorator> (default: null)typeAnnotation (default: null)t.ifStatement(test, consequent, alternate)
See also t.isIfStatement(node, opts) and t.assertIfStatement(node, opts).
Aliases: Statement, Conditional
test: Expression (required)consequent: Statement (required)alternate: Statement (default: null)t.import()
See also t.isImport(node, opts) and t.assertImport(node, opts).
Aliases: Expression
t.importDeclaration(specifiers, source)
See also t.isImportDeclaration(node, opts) and t.assertImportDeclaration(node, opts).
Aliases: Statement, Declaration, ModuleDeclaration
specifiers: Array<ImportSpecifier | ImportDefaultSpecifier | ImportNamespaceSpecifier> (required)source: StringLiteral (required)t.importDefaultSpecifier(local)
See also t.isImportDefaultSpecifier(node, opts) and t.assertImportDefaultSpecifier(node, opts).
Aliases: ModuleSpecifier
local: Identifier (required)t.importNamespaceSpecifier(local)
See also t.isImportNamespaceSpecifier(node, opts) and t.assertImportNamespaceSpecifier(node, opts).
Aliases: ModuleSpecifier
local: Identifier (required)t.importSpecifier(local, imported)
See also t.isImportSpecifier(node, opts) and t.assertImportSpecifier(node, opts).
Aliases: ModuleSpecifier
local: Identifier (required)imported: Identifier (required)importKind: null | 'type' | 'typeof' (default: null)t.interfaceDeclaration(id, typeParameters, extends, body)
See also t.isInterfaceDeclaration(node, opts) and t.assertInterfaceDeclaration(node, opts).
Aliases: Flow, FlowDeclaration, Statement, Declaration
id (required)typeParameters (required)extends (required)body (required)t.interfaceExtends(id, typeParameters)
See also t.isInterfaceExtends(node, opts) and t.assertInterfaceExtends(node, opts).
Aliases: Flow
id (required)typeParameters (required)t.intersectionTypeAnnotation(types)
See also t.isIntersectionTypeAnnotation(node, opts) and t.assertIntersectionTypeAnnotation(node, opts).
Aliases: Flow
types (required)t.jSXAttribute(name, value)
See also t.isJSXAttribute(node, opts) and t.assertJSXAttribute(node, opts).
Aliases: JSX, Immutable
name: JSXIdentifier | JSXNamespacedName (required)value: JSXElement | StringLiteral | JSXExpressionContainer (default: null)t.jSXClosingElement(name)
See also t.isJSXClosingElement(node, opts) and t.assertJSXClosingElement(node, opts).
Aliases: JSX, Immutable
name: JSXIdentifier | JSXMemberExpression (required)t.jSXElement(openingElement, closingElement, children, selfClosing)
See also t.isJSXElement(node, opts) and t.assertJSXElement(node, opts).
Aliases: JSX, Immutable, Expression
openingElement: JSXOpeningElement (required)closingElement: JSXClosingElement (default: null)children: Array<JSXText | JSXExpressionContainer | JSXSpreadChild | JSXElement> (required)selfClosing (required)t.jSXEmptyExpression()
See also t.isJSXEmptyExpression(node, opts) and t.assertJSXEmptyExpression(node, opts).
Aliases: JSX, Expression
t.jSXExpressionContainer(expression)
See also t.isJSXExpressionContainer(node, opts) and t.assertJSXExpressionContainer(node, opts).
Aliases: JSX, Immutable
expression: Expression (required)t.jSXIdentifier(name)
See also t.isJSXIdentifier(node, opts) and t.assertJSXIdentifier(node, opts).
Aliases: JSX, Expression
name: string (required)t.jSXMemberExpression(object, property)
See also t.isJSXMemberExpression(node, opts) and t.assertJSXMemberExpression(node, opts).
Aliases: JSX, Expression
object: JSXMemberExpression | JSXIdentifier (required)property: JSXIdentifier (required)t.jSXNamespacedName(namespace, name)
See also t.isJSXNamespacedName(node, opts) and t.assertJSXNamespacedName(node, opts).
Aliases: JSX
namespace: JSXIdentifier (required)name: JSXIdentifier (required)t.jSXOpeningElement(name, attributes, selfClosing)
See also t.isJSXOpeningElement(node, opts) and t.assertJSXOpeningElement(node, opts).
Aliases: JSX, Immutable
name: JSXIdentifier | JSXMemberExpression (required)attributes: Array<JSXAttribute | JSXSpreadAttribute> (required)selfClosing: boolean (default: false)t.jSXSpreadAttribute(argument)
See also t.isJSXSpreadAttribute(node, opts) and t.assertJSXSpreadAttribute(node, opts).
Aliases: JSX
argument: Expression (required)t.jSXSpreadChild(expression)
See also t.isJSXSpreadChild(node, opts) and t.assertJSXSpreadChild(node, opts).
Aliases: JSX, Immutable
expression: Expression (required)t.jSXText(value)
See also t.isJSXText(node, opts) and t.assertJSXText(node, opts).
Aliases: JSX, Immutable
value: string (required)t.labeledStatement(label, body)
See also t.isLabeledStatement(node, opts) and t.assertLabeledStatement(node, opts).
Aliases: Statement
label: Identifier (required)body: Statement (required)t.logicalExpression(operator, left, right)
See also t.isLogicalExpression(node, opts) and t.assertLogicalExpression(node, opts).
Aliases: Binary, Expression
operator: '||' | '&&' (required)left: Expression (required)right: Expression (required)t.memberExpression(object, property, computed)
See also t.isMemberExpression(node, opts) and t.assertMemberExpression(node, opts).
Aliases: Expression, LVal
object: Expression (required)propertyif computed then Expression else Identifier (required)computed: boolean (default: false)t.metaProperty(meta, property)
See also t.isMetaProperty(node, opts) and t.assertMetaProperty(node, opts).
Aliases: Expression
meta: string (required)property: string (required)t.mixedTypeAnnotation()
See also t.isMixedTypeAnnotation(node, opts) and t.assertMixedTypeAnnotation(node, opts).
Aliases: Flow, FlowBaseAnnotation
t.newExpression(callee, arguments)
See also t.isNewExpression(node, opts) and t.assertNewExpression(node, opts).
Aliases: Expression
callee: Expression (required)arguments: Array<Expression | SpreadElement> (required)t.noop()
See also t.isNoop(node, opts) and t.assertNoop(node, opts).
t.nullLiteral()
See also t.isNullLiteral(node, opts) and t.assertNullLiteral(node, opts).
Aliases: Expression, Pureish, Literal, Immutable
t.nullLiteralTypeAnnotation()
See also t.isNullLiteralTypeAnnotation(node, opts) and t.assertNullLiteralTypeAnnotation(node, opts).
Aliases: Flow, FlowBaseAnnotation
t.nullableTypeAnnotation(typeAnnotation)
See also t.isNullableTypeAnnotation(node, opts) and t.assertNullableTypeAnnotation(node, opts).
Aliases: Flow
typeAnnotation (required)t.numberTypeAnnotation()
See also t.isNumberTypeAnnotation(node, opts) and t.assertNumberTypeAnnotation(node, opts).
Aliases: Flow, FlowBaseAnnotation
t.numericLiteral(value)
See also t.isNumericLiteral(node, opts) and t.assertNumericLiteral(node, opts).
Aliases: Expression, Pureish, Literal, Immutable
value: number (required)t.numericLiteralTypeAnnotation()
See also t.isNumericLiteralTypeAnnotation(node, opts) and t.assertNumericLiteralTypeAnnotation(node, opts).
Aliases: Flow
t.objectExpression(properties)
See also t.isObjectExpression(node, opts) and t.assertObjectExpression(node, opts).
Aliases: Expression
properties: Array<ObjectMethod | ObjectProperty | SpreadProperty> (required)t.objectMethod(kind, key, params, body, computed)
See also t.isObjectMethod(node, opts) and t.assertObjectMethod(node, opts).
Aliases: UserWhitespacable, Function, Scopable, BlockParent, FunctionParent, Method, ObjectMember
kind: "method" | "get" | "set" (default: 'method')keyif computed then Expression else Identifier | Literal (required)params (required)body: BlockStatement (required)computed: boolean (default: false)async: boolean (default: false)decorators: Array<Decorator> (default: null)generator: boolean (default: false)returnType (default: null)typeParameters (default: null)t.objectPattern(properties, typeAnnotation)
See also t.isObjectPattern(node, opts) and t.assertObjectPattern(node, opts).
Aliases: Pattern, LVal
properties: Array<RestProperty | Property> (required)typeAnnotation (required)decorators: Array<Decorator> (default: null)t.objectProperty(key, value, computed, shorthand, decorators)
See also t.isObjectProperty(node, opts) and t.assertObjectProperty(node, opts).
Aliases: UserWhitespacable, Property, ObjectMember
keyif computed then Expression else Identifier | Literal (required)value: Expression | Pattern | RestElement (required)computed: boolean (default: false)shorthand: boolean (default: false)decorators: Array<Decorator> (default: null)t.objectTypeAnnotation(properties, indexers, callProperties)
See also t.isObjectTypeAnnotation(node, opts) and t.assertObjectTypeAnnotation(node, opts).
Aliases: Flow
properties (required)indexers (required)callProperties (required)t.objectTypeCallProperty(value)
See also t.isObjectTypeCallProperty(node, opts) and t.assertObjectTypeCallProperty(node, opts).
Aliases: Flow, UserWhitespacable
value (required)t.objectTypeIndexer(id, key, value)
See also t.isObjectTypeIndexer(node, opts) and t.assertObjectTypeIndexer(node, opts).
Aliases: Flow, UserWhitespacable
id (required)key (required)value (required)t.objectTypeProperty(key, value)
See also t.isObjectTypeProperty(node, opts) and t.assertObjectTypeProperty(node, opts).
Aliases: Flow, UserWhitespacable
key (required)value (required)t.objectTypeSpreadProperty(argument)
See also t.isObjectTypeSpreadProperty(node, opts) and t.assertObjectTypeSpreadProperty(node, opts).
Aliases: Flow, UserWhitespacable
argument (required)t.opaqueType(id, typeParameters, impltype, supertype)
See also t.isOpaqueType(node, opts) and t.assertOpaqueType(node, opts).
Aliases: Flow, FlowDeclaration, Statement, Declaration
id (required)typeParameters (required)impltype (required)supertype (required)t.parenthesizedExpression(expression)
See also t.isParenthesizedExpression(node, opts) and t.assertParenthesizedExpression(node, opts).
Aliases: Expression, ExpressionWrapper
expression: Expression (required)t.program(body, directives)
See also t.isProgram(node, opts) and t.assertProgram(node, opts).
Aliases: Scopable, BlockParent, Block, FunctionParent
body: Array<Statement> (required)directives: Array<Directive> (default: [])t.qualifiedTypeIdentifier(id, qualification)
See also t.isQualifiedTypeIdentifier(node, opts) and t.assertQualifiedTypeIdentifier(node, opts).
Aliases: Flow
id (required)qualification (required)t.regExpLiteral(pattern, flags)
See also t.isRegExpLiteral(node, opts) and t.assertRegExpLiteral(node, opts).
Aliases: Expression, Literal
pattern: string (required)flags: string (default: '')t.restElement(argument, typeAnnotation)
See also t.isRestElement(node, opts) and t.assertRestElement(node, opts).
Aliases: LVal
argument: LVal (required)typeAnnotation (required)decorators: Array<Decorator> (default: null)t.restProperty(argument)
See also t.isRestProperty(node, opts) and t.assertRestProperty(node, opts).
Aliases: UnaryLike
argument: LVal (required)t.returnStatement(argument)
See also t.isReturnStatement(node, opts) and t.assertReturnStatement(node, opts).
Aliases: Statement, Terminatorless, CompletionStatement
argument: Expression (default: null)t.sequenceExpression(expressions)
See also t.isSequenceExpression(node, opts) and t.assertSequenceExpression(node, opts).
Aliases: Expression
expressions: Array<Expression> (required)t.spreadElement(argument)
See also t.isSpreadElement(node, opts) and t.assertSpreadElement(node, opts).
Aliases: UnaryLike
argument: Expression (required)t.spreadProperty(argument)
See also t.isSpreadProperty(node, opts) and t.assertSpreadProperty(node, opts).
Aliases: UnaryLike
argument: Expression (required)t.stringLiteral(value)
See also t.isStringLiteral(node, opts) and t.assertStringLiteral(node, opts).
Aliases: Expression, Pureish, Literal, Immutable
value: string (required)t.stringLiteralTypeAnnotation()
See also t.isStringLiteralTypeAnnotation(node, opts) and t.assertStringLiteralTypeAnnotation(node, opts).
Aliases: Flow
t.stringTypeAnnotation()
See also t.isStringTypeAnnotation(node, opts) and t.assertStringTypeAnnotation(node, opts).
Aliases: Flow, FlowBaseAnnotation
t.super()
See also t.isSuper(node, opts) and t.assertSuper(node, opts).
Aliases: Expression
t.switchCase(test, consequent)
See also t.isSwitchCase(node, opts) and t.assertSwitchCase(node, opts).
test: Expression (default: null)consequent: Array<Statement> (required)t.switchStatement(discriminant, cases)
See also t.isSwitchStatement(node, opts) and t.assertSwitchStatement(node, opts).
Aliases: Statement, BlockParent, Scopable
discriminant: Expression (required)cases: Array<SwitchCase> (required)t.taggedTemplateExpression(tag, quasi)
See also t.isTaggedTemplateExpression(node, opts) and t.assertTaggedTemplateExpression(node, opts).
Aliases: Expression
tag: Expression (required)quasi: TemplateLiteral (required)t.templateElement(value, tail)
See also t.isTemplateElement(node, opts) and t.assertTemplateElement(node, opts).
value (required)tail: boolean (default: false)t.templateLiteral(quasis, expressions)
See also t.isTemplateLiteral(node, opts) and t.assertTemplateLiteral(node, opts).
Aliases: Expression, Literal
quasis: Array<TemplateElement> (required)expressions: Array<Expression> (required)t.thisExpression()
See also t.isThisExpression(node, opts) and t.assertThisExpression(node, opts).
Aliases: Expression
t.thisTypeAnnotation()
See also t.isThisTypeAnnotation(node, opts) and t.assertThisTypeAnnotation(node, opts).
Aliases: Flow, FlowBaseAnnotation
t.throwStatement(argument)
See also t.isThrowStatement(node, opts) and t.assertThrowStatement(node, opts).
Aliases: Statement, Terminatorless, CompletionStatement
argument: Expression (required)t.tryStatement(block, handler, finalizer)
See also t.isTryStatement(node, opts) and t.assertTryStatement(node, opts).
Aliases: Statement
block (required)handler (default: null)finalizer: BlockStatement (default: null)body: BlockStatement (default: null)t.tupleTypeAnnotation(types)
See also t.isTupleTypeAnnotation(node, opts) and t.assertTupleTypeAnnotation(node, opts).
Aliases: Flow
types (required)t.typeAlias(id, typeParameters, right)
See also t.isTypeAlias(node, opts) and t.assertTypeAlias(node, opts).
Aliases: Flow, FlowDeclaration, Statement, Declaration
id (required)typeParameters (required)right (required)t.typeAnnotation(typeAnnotation)
See also t.isTypeAnnotation(node, opts) and t.assertTypeAnnotation(node, opts).
Aliases: Flow
typeAnnotation (required)t.typeCastExpression(expression, typeAnnotation)
See also t.isTypeCastExpression(node, opts) and t.assertTypeCastExpression(node, opts).
Aliases: Flow, ExpressionWrapper, Expression
expression (required)typeAnnotation (required)t.typeParameter(bound)
See also t.isTypeParameter(node, opts) and t.assertTypeParameter(node, opts).
Aliases: Flow
bound (required)t.typeParameterDeclaration(params)
See also t.isTypeParameterDeclaration(node, opts) and t.assertTypeParameterDeclaration(node, opts).
Aliases: Flow
params (required)t.typeParameterInstantiation(params)
See also t.isTypeParameterInstantiation(node, opts) and t.assertTypeParameterInstantiation(node, opts).
Aliases: Flow
params (required)t.typeofTypeAnnotation(argument)
See also t.isTypeofTypeAnnotation(node, opts) and t.assertTypeofTypeAnnotation(node, opts).
Aliases: Flow
argument (required)t.unaryExpression(operator, argument, prefix)
See also t.isUnaryExpression(node, opts) and t.assertUnaryExpression(node, opts).
Aliases: UnaryLike, Expression
operator: 'void' | 'delete' | '!' | '+' | '-' | '++' | '--' | '~' | 'typeof' (required)argument: Expression (required)prefix: boolean (default: true)t.unionTypeAnnotation(types)
See also t.isUnionTypeAnnotation(node, opts) and t.assertUnionTypeAnnotation(node, opts).
Aliases: Flow
types (required)t.updateExpression(operator, argument, prefix)
See also t.isUpdateExpression(node, opts) and t.assertUpdateExpression(node, opts).
Aliases: Expression
operator: '++' | '--' (required)argument: Expression (required)prefix: boolean (default: false)t.variableDeclaration(kind, declarations)
See also t.isVariableDeclaration(node, opts) and t.assertVariableDeclaration(node, opts).
Aliases: Statement, Declaration
kind: "var" | "let" | "const" (required)declarations: Array<VariableDeclarator> (required)t.variableDeclarator(id, init)
See also t.isVariableDeclarator(node, opts) and t.assertVariableDeclarator(node, opts).
id: LVal (required)init: Expression (default: null)t.voidTypeAnnotation()
See also t.isVoidTypeAnnotation(node, opts) and t.assertVoidTypeAnnotation(node, opts).
Aliases: Flow, FlowBaseAnnotation
t.whileStatement(test, body)
See also t.isWhileStatement(node, opts) and t.assertWhileStatement(node, opts).
Aliases: Statement, BlockParent, Loop, While, Scopable
test: Expression (required)body: BlockStatement | Statement (required)t.withStatement(object, body)
See also t.isWithStatement(node, opts) and t.assertWithStatement(node, opts).
Aliases: Statement
object (required)body: BlockStatement | Statement (required)t.yieldExpression(argument, delegate)
See also t.isYieldExpression(node, opts) and t.assertYieldExpression(node, opts).
Aliases: Expression, Terminatorless
argument: Expression (default: null)delegate: boolean (default: false)FAQs
Babel Types is a Lodash-esque utility library for AST nodes
We found that babel-types demonstrated a not healthy version release cadence and project activity because the last version was released a year ago. It has 5 open source maintainers collaborating on the project.
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