misc: add pytests.nix dev utility

pytests/iroha_cli_tests/README.md

@@ -194,3 +194,7 @@ allure serve allure-results
 ```
 
 The `allure-results` argument specifies the directory where the report is stored. After running this command, you will be able to view the report in your web browser by navigating to `http://localhost:port`, where `port` is the port number displayed in the terminal output.
+
+## Nix tool
+
+See [../../scripts/pytests.nix]

pytests/iroha_torii_tests/README.md

@@ -28,3 +28,7 @@ To run the automated tests, use the following command:
 ```bash
 poetry run pytest
 ```
+
+## Nix tool
+
+See [../../scripts/pytests.nix]

scripts/pytests.nix

@@ -0,0 +1,45 @@
+# This is for development convenience, to make setting up and running pytests straightforward.
+# This is not a final product, so feel free to edit manually to adjust tests running or do whatever is convenient
+#   for you right now.
+#
+# Build binaries: `cargo build --release --bins`
+# Run from the repo root: `nix-shell ./scripts/pytests.nix`
+# That's it
+with import <nixpkgs> {};
+  pkgs.mkShell {
+    buildInputs = [
+      poetry
+      python313Packages.tomli-w
+
+      cowsay
+    ];
+
+    BIN_IROHAD = "target/release/irohad";
+    BIN_IROHA = "target/release/iroha";
+    BIN_KAGAMI = "target/release/kagami";
+
+    TMP_DIR = "../../test";
+    IROHA_CLI_BINARY = "iroha";
+    IROHA_CLI_CONFIG = "client.toml";
+
+    shellHook = ''
+      ./scripts/test_env.py setup
+      echo "Set up test env"
+
+      cd pytests/iroha_cli_tests
+      poetry install --no-root
+      poetry run pytest
+
+      cd ../iroha_torii_tests
+      poetry install --no-root
+      poetry run pytest
+
+      cd ../../
+
+      ./scripts/test_env.py cleanup
+      echo "Cleaned up"
+
+      cowsay "Done!"
+      exit
+    '';
+  }