Add Pytest unit tests for serialization library

Tests run with `pytest` command in repository's root directory.

Signed-off-by: Kaushik Varadharajan <kaushik.varadharajan@arm.com>
Change-Id: I9d8a13b233ffafc9119ef503d46f7808461a194f

1 files changed, 45 insertions, 6 deletions

diff --git a/python/pytests/conftest.py b/python/pytests/conftest.py
index b595a01..1cb0857 100644
--- a/python/pytests/conftest.py
+++ b/python/pytests/conftest.py
@@ -16,6 +16,8 @@
 
 import pathlib
 import shutil
+import subprocess
+import pytest
 
 
 def pytest_sessionstart():
@@ -24,13 +26,50 @@ def pytest_sessionstart():
     base_dir = (pathlib.Path(__file__).parent / "../..").resolve()
     tmp_dir = base_dir / "python/pytests/tmp"
 
-    tmp_dir.mkdir(exist_ok=True)
+    if tmp_dir.exists():
+        shutil.rmtree(tmp_dir)
+    tmp_dir.mkdir()
 
+    # Using flatc and flatbuffers' reflection feature to convert tosa.fbs to
+    # json for easier reading
+    flatbuffers_dir = base_dir / "third_party/flatbuffers"
+    flatc = flatbuffers_dir / "flatc"
+    reflection_fbs = flatbuffers_dir / "reflection/reflection.fbs"
+    tosa_fbs = base_dir / "schema/tosa.fbs"
 
-def pytest_sessionfinish():
-    """Cleaning up temporary files."""
+    # Using flatbuffers reflection to serialize the TOSA flatbuffers schema
+    # into binary
+    _ = subprocess.run(
+        [flatc, "--binary", "--schema", "-o", tmp_dir, tosa_fbs], check=True
+    )
 
-    base_dir = (pathlib.Path(__file__).parent / "../..").resolve()
-    tmp_dir = base_dir / "python/pytests/tmp"
+    # This file is generated by the previous command
+    tosa_bfbs = tmp_dir / "tosa.bfbs"
+
+    # Deserializing the binary into JSON using the reflection schema
+    _ = subprocess.run(
+        [
+            flatc,
+            "--json",
+            "--strict-json",
+            "-o",
+            tmp_dir,
+            reflection_fbs,
+            "--",
+            tosa_bfbs,
+        ],
+        check=True,
+    )
+
+
+def pytest_addoption(parser: pytest.Parser):
+    parser.addoption("--leave-tmp", dest="leave_tmp", action="store_true")
+
+
+def pytest_sessionfinish(session: pytest.Session):
+    """Cleaning up temporary files, unless the --leave-tmp flag is set"""
 
-    shutil.rmtree(tmp_dir)
+    if not session.config.option.leave_tmp:
+        base_dir = (pathlib.Path(__file__).parent / "../..").resolve()
+        tmp_dir = base_dir / "python/pytests/tmp"
+        shutil.rmtree(tmp_dir)