Wflow ZMQ server: allow JSON reading and writing of NaN and Inf (#…

…513)

* Wflow server: allow JSON reading and writing of `NaN` and `Inf`
By setting `allow_inf` arg to `true`.

* Add small server test
To test if `NaN` values are allowed.

* Update changelog

docs/changelog.qmd

@@ -21,6 +21,9 @@ project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
   `SimpleReservoir` and `Lake` struct, and not to the corresponding river index. This
   resulted in incorrect surface water abstractions from reservoir and lake volumes, and
   surface water abstractions were set at zero at the wrong river locations.
+- Wflow ZMQ server: allow JSON reading and writing of `NaN` and `Inf` values to avoid a JSON
+  spec error. For example, during initialization of a wflow model, some (diagnostic) model
+  variables are initialized with `NaN` values.
 
 ### Changed
 - Removed vertical concepts `HBV` and `FLEXTopo`.

server/src/server.jl

@@ -89,7 +89,7 @@ function wflow_bmi(s::ZMQ.Socket, handler::ModelHandler, f)
             response(s)
         else
             @info "Send response including output from Wflow function `$(f.fn)`"
-            ZMQ.send(s, JSON3.write(ret))
+            ZMQ.send(s, JSON3.write(ret; allow_inf = true))
         end
     catch e
         @error "Wflow function `$(f.fn)` failed" exception = (e, catch_backtrace())
@@ -151,7 +151,7 @@ function start(port::Int)
         while true
             # Wait for next request from client
             req = ZMQ.recv(socket)
-            json = JSON3.read(req)
+            json = JSON3.read(req; allow_inf = true)
             @info "Received request to run function `$(json.fn)`..."
 
             if haskey(map_structs, json.fn)

server/test/client.jl

@@ -10,7 +10,7 @@ ZMQ.connect(socket, "tcp://localhost:5555")
 
 function request(message)
     ZMQ.send(socket, JSON3.write(message))
-    ret_value = JSON3.read(ZMQ.recv(socket), Dict)
+    ret_value = JSON3.read(ZMQ.recv(socket), Dict; allow_inf = true)
     return ret_value
 end
 
@@ -24,6 +24,12 @@ end
     @test request((fn = "get_time_units",)) == Dict("time_units" => "s")
 end
 
+@testset "Reading and writing NaN values allowed" begin
+    msg =
+        (fn = "get_value", name = "vertical.soil.variables.vwc[1]", dest = fill(0.0, 50063))
+    @test isnan(mean(request(msg)["value"]))
+end
+
 @testset "update functions" begin
     @test request((fn = "update_until", time = 86400.0)) == Dict("status" => "OK")
     @test request((fn = "get_current_time",)) == Dict("current_time" => 86400)