It appears that the repository has undergone several changes and renamings:

backend/node_modules/postcss-js/parser.js

@@ -1,104 +0,0 @@
-let postcss = require('postcss')
-
-let IMPORTANT = /\s*!important\s*$/i
-
-let UNITLESS = {
-  'box-flex': true,
-  'box-flex-group': true,
-  'column-count': true,
-  'flex': true,
-  'flex-grow': true,
-  'flex-positive': true,
-  'flex-shrink': true,
-  'flex-negative': true,
-  'font-weight': true,
-  'line-clamp': true,
-  'line-height': true,
-  'opacity': true,
-  'order': true,
-  'orphans': true,
-  'tab-size': true,
-  'widows': true,
-  'z-index': true,
-  'zoom': true,
-  'fill-opacity': true,
-  'stroke-dashoffset': true,
-  'stroke-opacity': true,
-  'stroke-width': true
-}
-
-function dashify(str) {
-  return str
-    .replace(/([A-Z])/g, '-$1')
-    .replace(/^ms-/, '-ms-')
-    .toLowerCase()
-}
-
-function decl(parent, name, value) {
-  if (value === false || value === null) return
-
-  if (!name.startsWith('--')) {
-    name = dashify(name)
-  }
-
-  if (typeof value === 'number') {
-    if (value === 0 || UNITLESS[name]) {
-      value = value.toString()
-    } else {
-      value += 'px'
-    }
-  }
-
-  if (name === 'css-float') name = 'float'
-
-  if (IMPORTANT.test(value)) {
-    value = value.replace(IMPORTANT, '')
-    parent.push(postcss.decl({ prop: name, value, important: true }))
-  } else {
-    parent.push(postcss.decl({ prop: name, value }))
-  }
-}
-
-function atRule(parent, parts, value) {
-  let node = postcss.atRule({ name: parts[1], params: parts[3] || '' })
-  if (typeof value === 'object') {
-    node.nodes = []
-    parse(value, node)
-  }
-  parent.push(node)
-}
-
-function parse(obj, parent) {
-  let name, value, node
-  for (name in obj) {
-    value = obj[name]
-    if (value === null || typeof value === 'undefined') {
-      continue
-    } else if (name[0] === '@') {
-      let parts = name.match(/@(\S+)(\s+([\W\w]*)\s*)?/)
-      if (Array.isArray(value)) {
-        for (let i of value) {
-          atRule(parent, parts, i)
-        }
-      } else {
-        atRule(parent, parts, value)
-      }
-    } else if (Array.isArray(value)) {
-      for (let i of value) {
-        decl(parent, name, i)
-      }
-    } else if (typeof value === 'object') {
-      node = postcss.rule({ selector: name })
-      parse(value, node)
-      parent.push(node)
-    } else {
-      decl(parent, name, value)
-    }
-  }
-}
-
-module.exports = function (obj) {
-  let root = postcss.root()
-  parse(obj, root)
-  return root
-}