Flutter: Unexpected character (at character 1) - json

Question

In Flutter, no matter what json file i try to decode I get the same above titled error.
Originally I thought it was something with my project but after starting a new template Flutter project I still receive the same error. I have the json file in my root folder and have added them to the pubspec.yaml file:
assets:
- Sample-JSON-data.json
- Sample-employee-JSON-data.json
Main.dart code at the moment:
var jsonString = 'Sample-JSON-data.json';
var response = jsonDecode(jsonString);
print(response);
I have verified my json data on multiple test sites as well as tried various methods in the Flutter Documentation. Json data:
{
"type": "FeatureCollection",
"features": [
{
"type": "Feature",
"geometry": {
"type": "Point",
"coordinates": [
151.0763783444317,
-33.98045132346684
]
}
},
{
"type": "Feature",
"geometry": {
"type": "Point",
"coordinates": [
151.07774912725728,
-33.97470462237792
]
}
},
{
"type": "Feature",
"geometry": {
"type": "Point",
"coordinates": [
151.07774912725728,
-33.97470462237792
]
}
},
{
"type": "Feature",
"geometry": {
"type": "Point",
"coordinates": [
151.07774912725728,
-33.97470462237792
]
}
},
{
"type": "Feature",
"geometry": {
"type": "Point",
"coordinates": [
151.0763783444317,
-33.98045132346684
]
}
},
{
"type": "Feature",
"geometry": {
"type": "Point",
"coordinates": [
151.07774912725728,
-33.97470462237792
]
}
},
{
"type": "Feature",
"geometry": {
"type": "Point",
"coordinates": [
151.07774912725728,
-33.97470462237792
]
}
},
{
"type": "Feature",
"geometry": {
"type": "Point",
"coordinates": [
151.07774912725728,
-33.97470462237792
]
}
},
{
"type": "Feature",
"geometry": {
"type": "Point",
"coordinates": [
151.0763783444317,
-33.98045132346684
]
}
}
]
}

Answer 1

jsonDecode expects an input to be valid JSON serialized into String fe.
{ "message": "Hello World!" }. So this would work: jsonDecode('{"message": "Hello World!"}').
What you are passing to it is a file name, it won't automatically read the file for you. You can check how to do that here:
Flutter - Read text file from assets

Answer 2

Actually you are not loading the data from the json file.
Try:
var jsonString = await rootBundle.loadString('Sample-JSON-data.json')