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

backend/node_modules/postcss/lib/fromJSON.js

@@ -1,54 +0,0 @@
-'use strict'
-
-let AtRule = require('./at-rule')
-let Comment = require('./comment')
-let Declaration = require('./declaration')
-let Input = require('./input')
-let PreviousMap = require('./previous-map')
-let Root = require('./root')
-let Rule = require('./rule')
-
-function fromJSON(json, inputs) {
-  if (Array.isArray(json)) return json.map(n => fromJSON(n))
-
-  let { inputs: ownInputs, ...defaults } = json
-  if (ownInputs) {
-    inputs = []
-    for (let input of ownInputs) {
-      let inputHydrated = { ...input, __proto__: Input.prototype }
-      if (inputHydrated.map) {
-        inputHydrated.map = {
-          ...inputHydrated.map,
-          __proto__: PreviousMap.prototype
-        }
-      }
-      inputs.push(inputHydrated)
-    }
-  }
-  if (defaults.nodes) {
-    defaults.nodes = json.nodes.map(n => fromJSON(n, inputs))
-  }
-  if (defaults.source) {
-    let { inputId, ...source } = defaults.source
-    defaults.source = source
-    if (inputId != null) {
-      defaults.source.input = inputs[inputId]
-    }
-  }
-  if (defaults.type === 'root') {
-    return new Root(defaults)
-  } else if (defaults.type === 'decl') {
-    return new Declaration(defaults)
-  } else if (defaults.type === 'rule') {
-    return new Rule(defaults)
-  } else if (defaults.type === 'comment') {
-    return new Comment(defaults)
-  } else if (defaults.type === 'atrule') {
-    return new AtRule(defaults)
-  } else {
-    throw new Error('Unknown node type: ' + json.type)
-  }
-}
-
-module.exports = fromJSON
-fromJSON.default = fromJSON