CODEWITHSUNDEEP
javascriptjsonnode.jsfs
Alexander Mills
Alexander Mills

Reputation: 100010

Parsing JSON output by splitting by some special character or character sequence

Some logging libraries write JSON strings to files and then parse them. I am writing a library for integration tests and want to know what the best way is to split the JSON strings so that I can create an array of the strings and then parse them one at a time.

This would be done like so:

var path = require('path');
var filePath = path.resolve(appRootPath + '/' + 'test/output/test1.txt');
var rstream = fs.createReadStream(filePath);

var data = '';

rstream
    .on('data', function (chunk) {
        data += chunk;
    })
    .on('end', function () {  // done
        var array = String(dataLength).split(';'); //spit the big string into an array of strings by some token

        doTheThing(array.filter(function (item) {   //filter and parse the array element by element
            return item && item.length > 0;
        }).map(function (item) {
            return JSON.parse(String(item));
        }));

    });

Below, I just put in semi-colons as a delineating character, however that won't be good enough for the obvious reasons.

So I am looking to parse something like this big string below (forgive the nonsense words like 'dogs' and 'cats'):

{"testId":21,"desc":"cats 1"};{"testId":18,"desc":"dogs 1"};{"testId":1,"desc":"makes stuff 1","error":{}};{"testId":22,"desc":"cats 2"};{"testId":19,"desc":"dogs 2"};{"testId":2,"desc":"makes stuff 2","error":{}};{"testId":20,"tests":[{"testId":21,"type":"it-standard","desc":"cats 1","complete":false,"error":null},{"testId":22,"type":"it-standard","desc":"cats 2","complete":false,"error":null}],"testsParallel":[],"loopTests":[],"children":[],"error":null};{"testId":17,"tests":[{"testId":18,"type":"it-standard","desc":"dogs 1","complete":false,"error":null},{"testId":19,"type":"it-standard","desc":"dogs 2","complete":false,"error":null}],"testsParallel":[],"loopTests":[],"children":[{"testId":20}],"error":null};{"testId":3,"desc":"makes stuff 2","error":null};{"testId":4,"desc":"makes stuff 2","error":{}};{"testId":10,"desc":"makes stuff 1","error":{}};{"testId":11,"desc":"makes stuff 2","error":null};{"testId":12,"desc":"makes stuff 3","error":{}};{"testId":14,"desc":"makes stuff 44","error":{}};{"testId":15,"desc":"makes stuff 888","error":{}};{"testId":16,"desc":"makes stuff 999","error":{}};{"testId":6,"desc":"makes stuff chard","error":{}};{"testId":7,"desc":"makes stuff heeee","error":{}};{"testId":8,"desc":"makes stuff raaa","error":{}};{"testId":0,"tests":[{"testId":1,"type":"it-standard","desc":"makes stuff 1","complete":false,"error":null},{"testId":2,"type":"it-standard","desc":"makes stuff 2","complete":false,"error":null},{"testId":3,"type":"it-standard","desc":"makes stuff 2","complete":false,"error":null},{"testId":4,"type":"it-standard","desc":"makes stuff 2","complete":false,"error":null}],"testsParallel":[{"testId":9,"tests":[{"testId":10,"type":"it-parallel","desc":"makes stuff 1","complete":false,"error":null},{"testId":11,"type":"it-parallel","desc":"makes stuff 2","complete":false,"error":null},{"testId":12,"type":"it-parallel","desc":"makes stuff 3","complete":false,"error":null}],"type":"ParallelTestSet"},{"testId":13,"tests":[{"testId":14,"type":"it-parallel","desc":"makes stuff 44","complete":false,"error":null},{"testId":15,"type":"it-parallel","desc":"makes stuff 888","complete":false,"error":null},{"testId":16,"type":"it-parallel","desc":"makes stuff 999","complete":false,"error":null}],"type":"ParallelTestSet"}],"loopTests":[{"testId":5,"tests":[{"testId":6,"type":"it-loop","desc":"makes stuff chard","complete":false,"error":null},{"testId":7,"type":"it-loop","desc":"makes stuff heeee","complete":false,"error":null},{"testId":8,"type":"it-loop","desc":"makes stuff raaa","complete":false,"error":null}],"type":"LoopTestSet"}],"children":[{"testId":17}],"error":null};

I need a clever way to delineate the would-be JS objects with some special character that can never appear in the output (I can control what ends up in the output, but that might require that I filter the end user's data that ends up on disk).

How is this done? Is there some super special character or character sequence I can use? Or is there a 'cleverer' way to do it that I am not thinking of?

Upvotes: 0

Views: 2187

Answers (1)

Mineotopia
Mineotopia

Reputation: 26

With JSON.parse() its possible to create an object out of a string. Maybe try it this way:

  • read the JSON file as a string

  • split the string into an array: string.split(';');

  • and now parse all the array entries in a loop with JSON.parse

Or just make an array in the JSON File and parse this complete thing

Upvotes: 1

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