[feature] Add mypy support to nix builds of pytket (#1138)

* Nix: added pyi interface files to pytket output, and added mypy checks on pytket and the tests into the checkPhase of the pytket nix derivation. Added result directory to .gitignore incase anyone runs nix build in the source directory.

* Removed unnecessary print statement from setup.py in nix builds

* Added space between loops in setup.py to keep the linter happy

* Additional lint fix

---------

Co-authored-by: Alec Edgington <54802828+cqc-alec@users.noreply.github.com>

.gitignore

@@ -31,3 +31,6 @@ pytket/tests/qasm_test_files/testout6.qasm
 # IDEs
 .idea
 .vscode
+
+#nix
+result

nix-support/pytket.nix

@@ -55,6 +55,7 @@ in {
       cp -r ${../pytket/pytket} pytket;
       cp ${../pytket/package.md} package.md;
       cp -r ${../schemas} schemas;
+      cp -r ${../pytket/mypy.ini} mypy.ini;
 
       # The usual build depends on setuptools-scm to extract the version.
       # We have already extracted the version within nix, so we can simply
@@ -80,6 +81,7 @@ in {
       } $out/lib/python${super.python3.pythonVersion}/site-packages/pytket/circuit/display/static;
     '';
     checkInputs = with super.python3.pkgs; [
+      mypy
       pytest
       pytest-cov
       pytest-benchmark
@@ -90,6 +92,11 @@ in {
     ] ++ [jsonschema-4180];
     checkPhase = ''
       export HOME=$TMPDIR;
+
+      # run mypy
+      python -m mypy --config-file=mypy.ini --no-incremental -p pytket -p test_root.tests;
+
+      # run tests
       chmod 700 $TMPDIR/test_root/tests/qasm_test_files;
       cd test_root/tests;
       python -m pytest -s .

pytket/setup.py

@@ -143,6 +143,10 @@ def run(self):
                 if not os.path.isdir(libpath):
                     shutil.copy(libpath, extdir)
 
+        for interface_file in os.listdir("pytket/_tket"):
+            if interface_file.endswith(".pyi") or interface_file.endswith(".py"):
+                shutil.copy(os.path.join("pytket/_tket", interface_file), extdir)
+
 
 plat_name = os.getenv("WHEEL_PLAT_NAME")