JavaScript: Change Json data array into new format

Question

I am trying to work with a json data which needs to be changed in many ways.

My current json data is following:

{
  "file1": {
    "function1": {
      "calls": {
        "105:4": {
          "file": "file2",
          "function": "function5"
        },
        "106:4": {
          "file": "file2",
          "function": "function6"
        }
      },
      "lines1": {
        "123": "102:0",
        "456": "105:8"
      },
      "lines2": {
        "102:0": [
          "102:0"
        ],
        "105:4": [
          "106:4",
          "107:1"
        ],
        "106:4": [
          "107:1"
        ]
      }
    }
  }
}

But I want the data as following:

{
  "name": "program",
  "children": [
    {
      "name": "file1",
      "children": [
        {
          "name": "function1",
          "calls": [
            {
              "line": 105,
              "file": "file2",
              "function": "function5"
            },
            {
              "line": 106,
              "file": "file2",
              "function": "function6"
            }
          ],
          "lines1": [
            102,
            105
          ],
          "lines2": [
            [
              102,
              102
            ],
            [
              105,
              106,
              107
            ],
            [
              106,
              107
            ]
          ],
          "group": 1
        }
      ],
      "group": 1
    }
  ],
  "group": 0
}

Here, number of files and functions are more. The value of first name is user defined. The group information is depend on the parent-child. Each file will have a group ascending group number and all the functions inside the file will also have the same group number. For the values for lines the first part before : are taken (104:4 becomes 104).

I have tried with following code so far, which is incomplete and not handling group information correctly.

function build(data) {
    return Object.entries(data).reduce((r, [key, value], idx) => {
      const obj = {
        name: 'program',
        children: [],
        group: 0,
        lines: []
      }

      if (key !== 'lines2) {
        obj.name = key;
        obj.children = build(value)
          if(!(key.includes(":")))
          obj.group = idx + 1;
      } else {
        if (!obj.lines) obj.lines = [];
        Object.entries(value).forEach(([k, v]) => {
          obj.lines.push([k, ...v].map(e => e.split(':').shift()))
        })
      }

      r.push(obj)
      return r;
    }, [])
  }

  const result = build(data);
  console.log(result);

I would really appreciate if you can help me out. Thanks in advance for your time.

Answer 1

Assuming the structure of your input is consistenly defined as shown in your question (ie, that no "saftey checks" are needed, etc), then you could approach this using a combination of Object.entries() , Array.map() and spread syntax as shown below.

See inline documentation in this code snippet for details on how to achieve that:

 function transformData(data, programName) { /* Define local parse helper to extract number from NUMBER:STRING format */ const parseHelper = (str) => Number.parseInt(str.split(':')[0]); /* Define local parse helper to extract group number from STRINGNUMBER format */ const parseGroup = (str) => Number.parseInt(str.replace(/^[az]+/,"")) /* Create a root object with specified program name */ return { name : programName, /* Iterate each file name and object entry of input */ children : Object.entries(input).map(([fileName, fileObject]) => { /* Iterate function name and object of current file object */ const fileChildren = Object.entries(fileObject) .map(([functionName, functionObject]) => { /* Iterate function name and object of current file object */ const lines = Object.entries(functionObject) .reduce((target, [functionKey, functionValue]) => { if(functionKey === "calls") { /* If function key is calls, interpret this value as data to be transformed to desired calls object shape */ const calls = Object.entries(functionValue) .map(([callKey, callObject]) => { return { line : parseHelper(callKey), file : callObject['file'], function : callObject['function'] } }); /* Inject calls object into lines result */ return { ...target, calls }; } else { /* Otherwise, interpret this value as data to be transformed to desired lines object shape */ const lineValues = Object.entries(functionValue) .map(([key, value]) => { /* If value is an array, map key/value pair to a nested array in resulting linesValues array */ return Array.isArray(value) ? [key, ...value] .map(parseHelper) : parseHelper(value) }) /* Inject line values into function key of result */ return { ...target, [functionKey] : lineValues } } }, {}); /* Inject lines into function result */ return { name : functionName, ...lines, group : parseGroup(functionName) } }); /* Map file object to name/children pairing */ return { name : fileName, children : fileChildren, group : parseGroup(fileName) } }), group : 0 } } const input = { "file1": { "function1": { "calls": { "105:4": { "file": "file2", "function": "function5" }, "106:4": { "file": "file2", "function": "function6" } }, "lines1": { "123": "102:0", "456": "105:8" }, "lines2": { "102:0": [ "102:0" ], "105:4": [ "106:4", "107:1" ], "106:4": [ "107:1" ] } } } }; console.log(transformData(input, "program"))

Hope that helps!