Json Parse Unexpected token with node - json

Question

I am getting a strange unexpected token error trying to parse a JSON file using node. I have tested the code with 2 files that look identical. I used a code compare tool to do a comparison and they do appear identical. However, when I try to parse them, one gets the error and the other does not. The file that does not work is being generated from a PowerShell script. The one that does work was manually created. I am baffled. One thing I noticed that is different about them when I write the json out to the console is, the one that does not work has a ? at the beginning.
The json from the file that does not work:
data = ?{ "stack_name": "perf-a", "parameters": { "StackSet": "b", "MonitoringEnableAutoscalingAlarm": "True", "MachineConfigEnvironment": "Perf", "AppEnvironmentType": "perf", "StackInRotation": "True", "MonitoringEnableNotificationOnlyAlarms": "False", "AMIImage": "ami-123456789" }, "tags": { "CostCenter": "12345", "Owner": "test#test.com" }, "cft_file":
"cft/cft.json"}
The json from the file that does work:
data = { "stack_name": "perf-a", "parameters": { "StackSet": "a", "MonitoringEnableAutoscalingAlarm": "True", "MachineConfigEnvironment": "Perf", "AppEnvironmentType": "perf", "StackInRotation": "True", "MonitoringEnableNotificationOnlyAlarms": "False", "AMIImage": "ami-123456789" }, "tags": { "CostCenter": "45229", "Owner": "test#test.com" }, "cft_file": "
cft/cft.json"}
The code I am using for testing is:
var envFile = "perf2.json";
var fs = require('fs');
console.log('envFile = ' + envFile);
fs.readFile(envFile, 'utf8', function (err, data) {
if (err) {
console.log('error reading variables file');
throw err;
}
try {
var JsonData = JSON.stringify(data);
console.log('JsonData = ' + JsonData);
data = data.replace(/\\n/g, "\\n")
.replace(/\\'/g, "\\'")
.replace(/\\"/g, '\\"')
.replace(/\\&/g, "\\&")
.replace(/\\r/g, "\\r")
.replace(/\\t/g, "\\t")
.replace(/\\b/g, "\\b")
.replace(/\\f/g, "\\f")
.replace(/\\0/g, "")
.replace(/\\v/g, "")
.replace(/\\e/g, "\\e");
data = data.replace(/[\u0000-\u001F]+/g, "");
console.log('data = ' + data);
var cftVariables = JSON.parse(data);
console.log('cftVariables = ' + cftVariables);
console.log('cftVariables stack name = ' + cftVariables.stack_name);
} catch (e) {
console.log('error parsing variables file');
throw e;
}
});
As you can see, I have also tried JSON.stringify but I lose the properties and cftVariables.stack_name becomes undefined.
This problem has been plaguing me for several days and I am now at a loss as to how to fix it.
For reference, here is the snippet of PowerShell that creates the file. The problem might be there.
$savePath = "envs/" +$filetouse + ".json"
$parameters = #{AppEnvironmentType =$AppEnvironmentType;
StackSet = $StackSet;
StackInRotation = $StackInRotation;
AMIImage = $amiid;
MonitoringEnableAutoscalingAlarm = $MonitoringEnableAutoscalingAlarm;
MonitoringEnableNotificationOnlyAlarms= $MonitoringEnableNotificationOnlyAlarms;
MachineConfigEnvironment = $MachineConfigEnvironment;
}
$tags = #{Owner = "test#test.com";
CostCenter = "45229";
}
$envcft = #{stack_name =$stack_name;
cft_file = "cft/cft.json";
parameters = $parameters;
tags = $tags;
} | ConvertTo-Json
Write-host("Saving the env file with the new amiId... ")
$envcft | Out-File $savePath -Encoding UTF8 -force

Answer 1

Assuming you are reading the data in from a file, once you have the string you can use the remove function to get rid of that "?".
Something like this:
s = s.replace('?','');
EDIT
since the replace did not work, try 1) either not specifying an encoding when you save the file, or 2) specify UTF16