I'm using a simple Node.js to pull information from a valid jsonfile (checked with JSLint), but the code i'm using doesn't return the expected value:
squadJSON = JSON.parse(fs.readFileSync('./squads/squad' + whichSquad + '.json'));
and it returns:
{ type: 'Buffer', data:
[ 123,
10,
32,
32,
34,
97,
99,
... 548 more items ] }
Any reason as to why this happens?
fs.readFileSync() returns a Buffer if you don't specify an encoding.
https://nodejs.org/api/fs.html#fs_fs_readfilesync_path_options
So, tell fs.readFileSync() what encoding to use:
squadJSON = JSON.parse(fs.readFileSync('./squads/squad' + whichSquad + '.json', 'utf8'));
fs.readFileSync('/path/to/file.json', 'utf8'). Thank you so much.The "why" has been answered by Sidney, but a better "what to do" would be to use require(), which supports parsing valid JSON files synchronously and returning the result as an object:
squadJSON = require('./squads/squad' + whichSquad + '.json');
or even nicer, using an ES6 template literal:
squadJSON = require(`./squads/squad${whichSquad}.json`);
One notable difference using require() is that it resolves relative paths from __dirname, which is the directory path of the current module, whereas fs methods resolve relative paths using process.cwd(), or "current working directory". It is the directory within a shell session from which the main module of the program is executed by node.
Hopefully the examples below demonstrate how their relative path resolution differs:
To make require(...) behave like JSON.parse(fs.readFileSync(..., 'utf8')):
const { resolve } = require('path');
function readFileSyncJson (path) {
return require(resolve(process.cwd(), path));
}
And to make JSON.parse(fs.readFileSync(..., 'utf8')) behave like require(...):
const { resolve } = require('path');
function requireJson (path) {
return JSON.parse(fs.readFileSync(resolve(__dirname, path), 'utf8'));
}
require is much more convenient for reading JSON files. Also, require always resolves relative to the file it's called in, whereas I believe fs.readFileSync resolves based the current working directory (unless you specifically resolve using __dirname).
require() is called from is in the same directory as (or is) the file you invoked using node.
JSON.parsedoes never return a buffer.