Convert XML files to JS objects.

xml2obj.js

// It converts simple XML structures to JS objects. The default value of a node is an
// empty string, as it should be (contrary to several libraries I tested).

const { DOMParser } = require('@xmldom/xmldom')

const loadChildNodesRecursive = node => {
  const nodes = {}
  Array.from(node.childNodes)
       .filter(element => element.nodeType === element.ELEMENT_NODE)
       .forEach(element => {
         let value
         // `<element></element>` or `<element/>`
         if (element.childNodes.length === 0) {
           value = ''
         // `<element>foo</element>`
         } else if (element.childNodes.length === 1 &&
                    element.childNodes[0].nodeValue !== null) {
           value = element.childNodes[0].nodeValue
         // ```
         //  <element>
         //    <foo></foo>
         //    <bar></bar>
         //    <etc></etc>
         //  </element>
         // ```
         //
         // or
         //
         // `<element><foo></foo><bar></bar><etc></etc></element>`
         //
         // or
         //
         // `<element><foo></foo></element>`
         } else if (element.childNodes.length > 1 ||
                    element.childNodes[0].nodeValue === null) {
           value = loadChildNodesRecursive(element)
         }
         // Property is not defined, let's just assign the value.
         if (nodes[element.tagName] === undefined) {
          nodes[element.tagName] = value
          return
         }
         // Property is already defined, we need to convert it to an array if necessary.
         if (!Array.isArray(nodes[element.tagName])) {
          nodes[element.tagName] = [nodes[element.tagName]]
         }
         // Property already exists, let's add the new value to the stack.
         nodes[element.tagName].push(value)
       })
  return nodes
}

module.exports = contents => {
  const handler = message => {
    throw new Error(message)
  }
  const domParser = new DOMParser(
    { errorHandler: { warning: handler, error: handler, fatalError: handler} }
  )
  return loadChildNodesRecursive(
    domParser.parseFromString(contents)
  )
}