CIR-1451: Don't give unnecessary details of json parse failures when …

…json payload is malformed.

app/controllers/CIRJsonErrorHandler.scala

@@ -0,0 +1,96 @@
+/*
+ * Copyright 2024 HM Revenue & Customs
+ *
+ */
+
+package controllers
+
+import play.api.http.Status.{BAD_REQUEST, NOT_FOUND}
+import play.api.libs.json.Json._
+import play.api.mvc.Results.{BadRequest, NotFound, Status}
+import play.api.mvc.{RequestHeader, Result}
+import play.api.{Configuration, Logger}
+import uk.gov.hmrc.http.HeaderCarrier
+import uk.gov.hmrc.play.audit.http.connector.AuditConnector
+import uk.gov.hmrc.play.bootstrap.backend.http.{ErrorResponse, JsonErrorHandler}
+import uk.gov.hmrc.play.bootstrap.config.HttpAuditEvent
+
+import javax.inject.Inject
+import scala.concurrent.{ExecutionContext, Future}
+
+class CIRJsonErrorHandler @Inject()(
+                                  auditConnector: AuditConnector,
+                                  httpAuditEvent: HttpAuditEvent,
+                                  configuration : Configuration
+                                )(implicit ec: ExecutionContext
+                                ) extends JsonErrorHandler(auditConnector, httpAuditEvent, configuration)(ec) {
+
+  import httpAuditEvent.dataEvent
+
+  private val logger = Logger(getClass)
+
+  override def onClientError(request: RequestHeader, statusCode: Int, message: String): Future[Result] = {
+    implicit val headerCarrier: HeaderCarrier = hc(request)
+    val result = statusCode match {
+      case NOT_FOUND =>
+        auditConnector.sendEvent(
+          dataEvent(
+            eventType       = "ResourceNotFound",
+            transactionName = "Resource Endpoint Not Found",
+            request         = request,
+            detail          = Map.empty
+          )
+        )
+        NotFound(toJson(ErrorResponse(NOT_FOUND, "URI not found", requested = Some(request.path))))
+
+      case BAD_REQUEST =>
+        auditConnector.sendEvent(
+          dataEvent(
+            eventType       = "ServerValidationError",
+            transactionName = "Request bad format exception",
+            request         = request,
+            detail          = Map.empty
+          )
+        )
+        def constructErrorMessage(input: String): String = {
+          val unrecognisedTokenJsonError = "^Invalid Json: Unrecognized token '(.*)':.*".r
+          val invalidJson                = "^(?s)Invalid Json:.*".r
+          val jsonValidationError        = "^Json validation error.*".r
+          val booleanParsingError        = "^Cannot parse parameter .* as Boolean: should be true, false, 0 or 1$".r
+          val missingParameterError      = "^Missing parameter:.*".r
+          val characterParseError        = "^Cannot parse parameter .* with value '(.*)' as Char: .* must be exactly one digit in length.$".r
+          val parameterParseError        = "^Cannot parse parameter .* as .*: For input string: \"(.*)\"$".r
+          input match {
+            case unrecognisedTokenJsonError(_)
+                 | invalidJson()
+                 | jsonValidationError()
+                 | booleanParsingError()
+                 | missingParameterError()                  => "invalid json"
+            case characterParseError(toBeRedacted)        => input.replace(toBeRedacted, "REDACTED")
+            case parameterParseError(toBeRedacted)        => input.replace(toBeRedacted, "REDACTED")
+            case _                                        => "bad request, cause: REDACTED"
+          }
+        }
+        val msg = constructErrorMessage(message)
+
+        BadRequest(toJson(ErrorResponse(BAD_REQUEST, msg)))
+
+      case _ =>
+        auditConnector.sendEvent(
+          dataEvent(
+            eventType       = "ClientError",
+            transactionName = s"A client error occurred, status: $statusCode",
+            request         = request,
+            detail          = Map.empty
+          )
+        )
+
+        val msg =
+          if (suppress4xxErrorMessages) "Other error"
+          else message
+
+        Status(statusCode)(toJson(ErrorResponse(statusCode, msg)))
+    }
+    Future.successful(result)
+  }
+}

conf/application.conf

@@ -17,7 +17,7 @@ include "backend.conf"
 appName = "address-lookup"
 
 play.http.router = prod.Routes
-play.http.errorHandler = "uk.gov.hmrc.play.bootstrap.backend.http.JsonErrorHandler"
+play.http.errorHandler = "controllers.CIRJsonErrorHandler"
 
 play.ws.timeout.request = 70000ms    # 70 secs