Cannot access value from case class - json

Question

I am trying to use the sttp core library along with the sttp json4s library in order to receive a json response and convert it to a case class.
The source code on Github is here and the documentation for this example that I am trying to replicate is here
The response to the GET request to the URL http://httpbin.org/get?foo=bar looks like:
{
"args": {
"foo": "bar"
},
"headers": {
"Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8",
"Accept-Encoding": "gzip,deflate",
"Accept-Language": "en-GB,en-US;q=0.9,en;q=0.8",
"Connection": "close",
"Cookie": "_gauges_unique_day=1; _gauges_unique_month=1; _gauges_unique_year=1; _gauges_unique=1; stale_after=never",
"Forwarded": "for=49.255.235.138",
"Host": "httpbin.org",
"Save-Data": "on",
"Scheme": "http",
"Upgrade-Insecure-Requests": "1",
"User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.94 Safari/537.36"
},
"origin": "49.255.235.138, 66.249.82.79",
"url": "http://httpbin.org/get?foo=bar"
}
The case class which attempts to read the json response above looks like:
case class HttpBinResponse(
args: Map[String, String],
origin: String,
headers: Map[String,String]
)
The case class has been defined at the top of the test file and is accessible to the test.
This test passes:
it should "send a GET request parse response as JSON" in {
implicit val backend = HttpURLConnectionBackend()
val queryParams = Map("foo" -> "bar", "bugs" -> "life")
val endpoint:Uri = uri"http://httpbin.org/get?foo=bar"
val request = sttp
.get(endpoint)
.response(asJson[HttpBinResponse])
val response = request.send()
// response.body is an Either
response.code should be(200)
val res = response.body.fold(_ => { "Error" }, a => { a })
res shouldBe a[HttpBinResponse]
}
The code that produces the error looks like this:
it should "send a GET request parse response as JSON" in {
implicit val backend = HttpURLConnectionBackend()
val queryParams = Map("foo" -> "bar", "bugs" -> "life")
val endpoint:Uri = uri"http://httpbin.org/get?foo=bar"
val request = sttp
.get(endpoint)
.response(asJson[HttpBinResponse])
val response = request.send()
// response.body is an Either
response.code should be(200)
val res = response.body.fold(_ => { "Error" }, a => { a })
res shouldBe a[HttpBinResponse]
println(res.origin)
}
However, when I try and access a value from the res.origin, I see the error that is value origin is not a member of java.io.Serializable
28. Waiting for source changes... (press enter to interrupt)
[info] Compiling 1 Scala source to /Users/localuser/Do/scalaexercises/target/scala-2.12/test-classes...
[error] /Users/localuser/Do/scalaexercises/src/test/scala/example/SttpSpec.scala:58: value origin is not a member of java.io.Serializable
[error] println(res.origin)
[error] ^
[error] one error found
[error] (test:compileIncremental) Compilation failed

Answer 1

The question was answered by Rob Norris on the gitter scala channel as:
When you fold the Either the result is Serializable. Try pattern matching on it, or fold to sys.error instead of String.
Pattern Matching on the result:
val res = response.body.fold(_ => { "Error" }, a => { a })
res match {
case HttpBinResponse(_, origin) => {
println("-----------------------------")
print("The origin for the request is ")
print(origin)
println("-----------------------------")
}
case _ => "Error"
}
fold the Left to sys.error instead of String, no pattern matching needed in this case:
val res = response.body.fold(
_ => { error("Error") },
a => { a }
)
println(res.origin)
res.args should contain("foo" -> "bar")
res.args should contain key("bugs")
res.args should contain value("life")
res.origin.length should be >10
Either of these two approaches would solve the issue.