A few comments:
1) Not sure what version of node you are using but fs.exists is deprecated
with fs.stat being one of the recommended replacements.
2) Using either fs.exists or fs.stat both are asynchronous function so will
not immediately execute the callback function which means the following
require happens immediately.
3) If you did use the synchronous version of fs.stat, depending on how
paranoid you want to be, there is a potential race condition between the
stats check and require call.
An alternative approach would be to use the fact that require is a
synchronous function and will throw an error with a specific code if the
module can't be found:
var fs = require('fs');
// initialize with defaults
var config = {
port: 8282
};
try {
// attempt to override the defaults
config = require('./config.json');
} catch (error) {
// only handle a missing module error
if (error.code !== 'MODULE_NOT_FOUND') {
throw error;
}
// asynchronously write out the default config
fs.writeFile('./config.json', JSON.stringify(config), function(error) {
if (error) {
throw error;
}
});
}
// at this point config will be the default if config.json didn't exist
// or the contents of config.json if it did exist
console.log(config);
-- Daniel R. <[email protected]> [http://danielr.neophi.com/]
On Thu, Mar 17, 2016 at 12:35 PM, Noel Hibbard <[email protected]>
wrote:
> I am brand new to Node and so far things have gone smooth but I am trying
> to put some settings in a config.json and use require to load them. My
> problem is the first time the tool runs the file does not exist so I wrote
> some code to check to see if it exists and if not I create a default config
> file and then once it's created I load it with require. My problem is it
> seems to be executing require before my code that creates the default
> config and then throws an error.
>
> Here is some sample code, I must be missing something basic:
> var fs = require('fs');
>
> fs.exists('./config.json', (exists) => {
> if(!exists)
> {
> fs.writeFile('./config.json', '{ "port" : "8282"}', function (err)
> {
> if (err) return console.log(err);
> });
> }
> });
>
> var config = require('./config.json');
>
> console.log(config.port);
>
> Thanks!
>
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