libtorch-bin: cleanup passthru test

- Make passthru.tests an attrset.
- Remove CMake VERBOSE option.
- Remove spurious `cat CMakeLists.txt`.
- Run the test as well.
- Actually test some functionality.

3 files changed, 18 insertions, 9 deletions

diff --git a/pkgs/development/libraries/science/math/libtorch/bin.nix b/pkgs/development/libraries/science/math/libtorch/bin.nix
index 33229bbefc82..6180c14c4d72 100644
--- a/pkgs/development/libraries/science/math/libtorch/bin.nix
+++ b/pkgs/development/libraries/science/math/libtorch/bin.nix
@@ -100,7 +100,7 @@ in stdenv.mkDerivation {
 
   outputs = [ "out" "dev" ];
 
-  passthru.tests = callPackage ./test { };
+  passthru.tests.cmake = callPackage ./test { };
 
   meta = with stdenv.lib; {
     description = "C++ API of the PyTorch machine learning framework";
diff --git a/pkgs/development/libraries/science/math/libtorch/test/default.nix b/pkgs/development/libraries/science/math/libtorch/test/default.nix
index d661ec28db98..e69807871f46 100644
--- a/pkgs/development/libraries/science/math/libtorch/test/default.nix
+++ b/pkgs/development/libraries/science/math/libtorch/test/default.nix
@@ -6,16 +6,12 @@ stdenv.mkDerivation {
 
   src = ./.;
 
-  postPatch = ''
-    cat CMakeLists.txt
-  '';
-
-  makeFlags = [ "VERBOSE=1" ];
-
   nativeBuildInputs = [ cmake ];
 
   buildInputs = [ libtorch-bin ];
 
+  doCheck = true;
+
   installPhase = ''
     touch $out
   '';
diff --git a/pkgs/development/libraries/science/math/libtorch/test/test.cpp b/pkgs/development/libraries/science/math/libtorch/test/test.cpp
index 5537724ce5f6..ca238fba521d 100644
--- a/pkgs/development/libraries/science/math/libtorch/test/test.cpp
+++ b/pkgs/development/libraries/science/math/libtorch/test/test.cpp
@@ -1,7 +1,20 @@
-#include <torch/torch.h>
+#undef NDEBUG
+#include <cassert>
+
 #include <iostream>
 
+#include <torch/torch.h>
+
 int main() {
   torch::Tensor tensor = torch::eye(3);
-  std::cout << tensor << std::endl;
+
+  float checkData[] = {
+    1, 0, 0,
+    0, 1, 0,
+    0, 0, 1
+  };
+
+  torch::Tensor check = torch::from_blob(checkData, {3, 3});
+
+  assert(tensor.allclose(check));
 }