Create a new Unist tree by mapping (to an array) and flattening
Create a new Unist tree by mapping (to an array) with the provided function and
then flattening.
Helper for creating unist: Universal Syntax Tree.
``sh`
npm install unist-util-flatmap
flatMap function returns new AST object, but the argument function should return
an array of ASTs.
`js
const assert = require('assert')
const assign = require('object-assign')
const flatMap = require('unist-util-flatmap')
// Input
const tree = {
type: 'root',
children: [
{
type: 'node',
children: [{type: 'leaf', value: '1'}]
},
{type: 'leaf', value: '2'}
]
}
// Transform:
const actual = flatMap(tree, node => {
if (node.type === 'leaf') {
return [
assign({}, node, {value: 'FIRST'}),
assign({}, node, {value: 'SECOND'})
]
}
// No change
return [node]
})
// Expected output:
const expected = {
type: 'root',
children: [
{
type: 'node',
children: [
{type: 'leaf', value: 'FIRST'},
{type: 'leaf', value: 'SECOND'}
]
},
{type: 'leaf', value: 'FIRST'},
{type: 'leaf', value: 'SECOND'}
]
}
assert.deepEqual(actual, expected)
`
`sh``
npm test