Package Exports
- estree-util-value-to-estree
Readme
estree-util-value-to-estree
Convert a JavaScript value to an ESTree expression.
Table of Contents
Installation
npm install estree-util-value-to-estreeUsage
This package converts a JavaScript value to an ESTree expression for values that can be constructed without the need for a context.
Currently the following types are supported:
bigintbooleannullnumber(Including Infinity and NaN)string- Shared
symbol object- null-prototype
Object undefinedArrayBigInt64ArrayBigUint64ArrayBooleanBufferDateFloat32ArrayFloat64ArrayInt16ArrayInt32ArrayInt8ArrayMapNumberRegExpSetStringUint16ArrayUint32ArrayUint8ArrayUint8ClampedArrayURLURLSearchParams
If options.instanceAsObject is set to true, other objects are turned into plain object.
import assert from 'node:assert/strict'
import { valueToEstree } from 'estree-util-value-to-estree'
const result = valueToEstree({
null: null,
undefined,
string: 'Hello world!',
number: 42,
negativeNumber: -1337,
infinity: Number.POSITIVE_INFINITY,
notANumber: Number.NaN,
regex: /\w+/i,
date: new Date('1970-01-01'),
array: ['I’m an array item!'],
object: { nested: 'value' }
})
assert.deepEqual(result, {
type: 'ObjectExpression',
properties: [
{
type: 'Property',
method: false,
shorthand: false,
computed: false,
kind: 'init',
key: { type: 'Literal', value: 'null' },
value: { type: 'Literal', value: null }
},
{
type: 'Property',
method: false,
shorthand: false,
computed: false,
kind: 'init',
key: { type: 'Literal', value: 'undefined' },
value: { type: 'Identifier', name: 'undefined' }
},
{
type: 'Property',
method: false,
shorthand: false,
computed: false,
kind: 'init',
key: { type: 'Literal', value: 'string' },
value: { type: 'Literal', value: 'Hello world!' }
},
{
type: 'Property',
method: false,
shorthand: false,
computed: false,
kind: 'init',
key: { type: 'Literal', value: 'number' },
value: { type: 'Literal', value: 42 }
},
{
type: 'Property',
method: false,
shorthand: false,
computed: false,
kind: 'init',
key: { type: 'Literal', value: 'negativeNumber' },
value: {
type: 'UnaryExpression',
operator: '-',
prefix: true,
argument: { type: 'Literal', value: 1337 }
}
},
{
type: 'Property',
method: false,
shorthand: false,
computed: false,
kind: 'init',
key: { type: 'Literal', value: 'infinity' },
value: { type: 'Identifier', name: 'Infinity' }
},
{
type: 'Property',
method: false,
shorthand: false,
computed: false,
kind: 'init',
key: { type: 'Literal', value: 'notANumber' },
value: { type: 'Identifier', name: 'NaN' }
},
{
type: 'Property',
method: false,
shorthand: false,
computed: false,
kind: 'init',
key: { type: 'Literal', value: 'regex' },
value: {
type: 'Literal',
value: /\w+/i,
regex: { pattern: '\\w+', flags: 'i' }
}
},
{
type: 'Property',
method: false,
shorthand: false,
computed: false,
kind: 'init',
key: { type: 'Literal', value: 'date' },
value: {
type: 'NewExpression',
callee: { type: 'Identifier', name: 'Date' },
arguments: [{ type: 'Literal', value: 0 }]
}
},
{
type: 'Property',
method: false,
shorthand: false,
computed: false,
kind: 'init',
key: { type: 'Literal', value: 'array' },
value: {
type: 'ArrayExpression',
elements: [{ type: 'Literal', value: 'I’m an array item!' }]
}
},
{
type: 'Property',
method: false,
shorthand: false,
computed: false,
kind: 'init',
key: { type: 'Literal', value: 'object' },
value: {
type: 'ObjectExpression',
properties: [
{
type: 'Property',
method: false,
shorthand: false,
computed: false,
kind: 'init',
key: { type: 'Literal', value: 'nested' },
value: { type: 'Literal', value: 'value' }
}
]
}
}
]
})
class Point {
line: number
column: number
constructor(line: number, column: number) {
this.line = line
this.column = column
}
}
// Normally complex objects throw.
assert.throws(() => valueToEstree(new Point(2, 3)))
// `instanceAsObject: true` treats them as plain objects.
assert.deepEqual(valueToEstree(new Point(2, 3), { instanceAsObject: true }), {
type: 'ObjectExpression',
properties: [
{
type: 'Property',
method: false,
shorthand: false,
computed: false,
kind: 'init',
key: { type: 'Literal', value: 'line' },
value: { type: 'Literal', value: 2 }
},
{
type: 'Property',
method: false,
shorthand: false,
computed: false,
kind: 'init',
key: { type: 'Literal', value: 'column' },
value: { type: 'Literal', value: 3 }
}
]
})API
This API exports the function valueToEstree.
valueToEstree(value, options?)
Convert a value to an ESTree node.
options
instanceAsObject(boolean, default:false) — If true, treat objects that have a prototype as plain objects.preserveReferences(boolean, default:false) — If true, preserve references to the same object found within the input. This also allows to serialize recursive structures. If needed, the resulting expression will be an iife.
Compatibility
This project is compatible with Node.js 16 or greater.