added skip for summaries with nothing in deserializtaion iterator

src/Deserialization/deserialization.jl

@@ -187,6 +187,12 @@ function Base.iterate(iter::SummaryDeserializingIterator, state=1)
 
     (tag, summary), i_state = res
 
+    # This can happen in certain cases, e.g. if hyperparameters have been recorded.
+    if summary.value === nothing
+        # Hence, we just skip it.
+        return Base.iterate(iter, state + 1)
+    end
+
     typ = summary_type(summary)
     if typ === :histo
         val = deserialize_histogram_summary(summary)

test/test_hparams.jl

@@ -88,4 +88,19 @@ end
         decoded_v = hv.kind.value
         @test expected_hparams_config[k] == decoded_v
     end
+end
+
+@testset "Reading with hparams present (#137)" begin
+    # https://github.com/JuliaLogging/TensorBoardLogger.jl/issues/137
+    lg = TBLogger(joinpath(mktempdir(), "logs"))
+    TensorBoardLogger.write_hparams!(
+        lg,
+        Dict("hi" => 1.0),
+        ["x/val"]
+    )
+    with_logger(lg) do
+        @info "x" val=3.0
+    end
+    hist = convert(MVHistory, lg)
+    @test haskey(hist, "x/val")
 end