fix GlobalPooling with graph only input

src/layers/pool.jl

@@ -40,6 +40,8 @@ function (l::GlobalPool)(g::GNNGraph, x::AbstractArray)
     return reduce_nodes(l.aggr, g, x)
 end
 
+(l::GlobalPool)(g::GNNGraph) = GNNGraph(g, gdata=l(g, node_features(g)))
+
 """
     TopKPool(adj, k, in_channel)
 

src/utils.jl

@@ -52,7 +52,6 @@ function normalize_graphdata(data::NamedTuple; default_name, n, duplicate_if_nee
     end
 
     sz = map(x -> x isa AbstractArray ? size(x)[end] : 0, data)
-
     if duplicate_if_needed 
         # Used to copy edge features on reverse edges    
         @assert all(s -> s == 0 ||  s == n || s == n÷2, sz)

test/layers/pool.jl

@@ -2,9 +2,11 @@
     @testset "GlobalPool" begin
         n = 10
         X = rand(16, n)
-        g = GNNGraph(random_regular_graph(n, 4))
+        g = GNNGraph(random_regular_graph(n, 4), ndata=X)
         p = GlobalPool(+)
-        @test p(g, X) ≈ NNlib.scatter(+, X, ones(Int, n))
+        y = p(g, X)
+        @test y ≈ NNlib.scatter(+, X, ones(Int, n))
+        test_layer(p, g, rtol=1e-5, exclude_grad_fields = [:aggr], outtype=:graph)
     end
 
     @testset "TopKPool" begin

test/test_utils.jl

@@ -18,6 +18,7 @@ function test_layer(l, g::GNNGraph; atol = 1e-7, rtol = 1e-5,
                                  verbose = false,
                                  test_gpu = TEST_GPU,
                                  outsize = nothing,
+                                 outtype = :node,
                                 )
 
     # TODO these give errors, probably some bugs in ChainRulesTestUtils
@@ -57,8 +58,15 @@ function test_layer(l, g::GNNGraph; atol = 1e-7, rtol = 1e-5,
     @test ycoo ≈ y    
 
     g′ = f(l, g)
-    @test g′.ndata.x ≈ y
-
+    if outtype == :node
+        @test g′.ndata.x ≈ y
+    elseif outtype == :edge
+        @test g′.edata.e ≈ y    
+    elseif outtype == :graph
+        @test g′.gdata.u ≈ y
+    else
+        @error "wrong outtype $outtype"
+    end
     if test_gpu
         ygpu = f(lgpu, ggpu, xgpu)
         @test ygpu isa CuArray