Question 110880 in Json Question posted in
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Replace a value in a json file with value from another file using fs

I want to read the values of key, access, path, bucket and bucketPath and use them in the JSON file test.json.

I have a function that reads the content of configuration.js and attempts to write to test.json. Currently, I am able to write the values of bucket.I get the changed/new values and lines of null for the rest of the json.

I want to always return the new values and the other objects in the file. Also, in cases where bucket already has a value, I want it replaced by whatever is read from configuration.json

How can I fix this, and how can i change the values for the rest access, key, path and bucketpath?

index.js

const fs = require("fs").promises;

async function readJSON(filePath, values) {
  const data = await fs.readFile(filePath);
  try {
    return JSON.parse(data);
  } catch (err) {
    console.log(err);
  }
}

(async() => {
  const credentials = await readJSON("./configuration.json");
  const path = credentials.path;
  const bucket = credentials.bucket;
  const access = credentials.access;
  const key = credentials.key;
  const bucketPath = credentials.bucketPath;

  const data = await jsonReader("./test.json");

  const finalJSON = data.data ? .map((x) => {
    if (x.type == "s3 credentials") return { ...x, bucket };
  });
  await fs.writeFile(
    "./test.json",
    JSON.stringify({
      data: finalJSON
    })
  );
})();

test.json

{
    "label": "storage record",
    "data": [{
            "id": "8902uw",
            "type": "config",
            "values": {
                "access": "$access",
                "key": "$key"
            }
        },
        {
            "id": "893wh002jei",
            "type": "s3 credentials",
            "bucket": ""
        },
        {
            "id": "90yueps",
            "type": "upload",
            "input": "localhost: `$path`"
        },
        {
            "id": "9028901",
            "type": "change",
            "name": "Adjust data",
            "measure": [{
                    "t": "setter"
                },
                {

                    "p": "filename",
                    "to": "$join(["$bucketPath", data])"
                }
            ],
            "fixed": ""
        }

    ]
}

configuration.json

{
    "key": "880082",
    "access": "793082",
    "path": "/store",
    "bucket": "testBucket",
    "bucketPath": "/record"
}

Currently, when I run this, I get:

{
    null,
    "data": [{
            null,
            null,
            null,
            null
        {
            "id": "893wh002jei",
            "type": "s3 credentials",
            "bucket": ""
        },
        {
        null,
        null,
        null
    ]
}
Tags:

2

Answers


  1. 0

    [Updated answer]

    From what you comment:

    it’s the same question. So when I run what I have, I get null for the other objects. I want test.json to remain the same just with updated values.

    const testObj = await jsonReader("./test.json");

const finalJSON = {
    ...testObj,
    data: testObj.data?.map((x) => {
        if (x.type === 's3 credentials') {
            return { ...x, bucket };
        } else {
            return x;
        }
    })
}

// which the code I gave above,
// the `finalJSON` now is the clone of the original from `test.json`
// plus updated values
await fs.writeFile(
    "./test.json",
    JSON.stringify(finalJSON)
);

    [Original answer]

    There is a problem with the function you pass to the map function.

    The condition if without else.

    I think you need else { return x; } to return original data if x.type is not what you expected.

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  2. 0

    might this be a solution !

    const fs = require('fs');
const fileName = './file.json';
const file = require(fileName);
    
file.key = "new value";
    
fs.writeFile(fileName, JSON.stringify(file), function writeJSON(err) {
  if (err) return console.log(err);
  console.log(JSON.stringify(file));
  console.log('writing to ' + fileName);
});
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