From 9ee421ec6db5a49b63a84a20a08889cc8846fe37 Mon Sep 17 00:00:00 2001
From: Michael Boulton <michaelboulton@gmail.com>
Date: Sat, 17 Aug 2019 15:41:02 +0100
Subject: [PATCH] Add hook which is called before every test

---
 tavern/testutils/pytesthook/__init__.py |  4 ++--
 tavern/testutils/pytesthook/hooks.py    |  7 +++++++
 tavern/testutils/pytesthook/item.py     | 13 +++++++++++--
 tavern/testutils/pytesthook/newhooks.py | 19 +++++++++++++++++++
 tests/unit/conftest.py                  |  2 ++
 5 files changed, 41 insertions(+), 4 deletions(-)
 create mode 100644 tavern/testutils/pytesthook/newhooks.py

diff --git a/tavern/testutils/pytesthook/__init__.py b/tavern/testutils/pytesthook/__init__.py
index 5028b0b5e..cb66a34d5 100644
--- a/tavern/testutils/pytesthook/__init__.py
+++ b/tavern/testutils/pytesthook/__init__.py
@@ -1,4 +1,4 @@
-from .hooks import pytest_collect_file, pytest_addoption
+from .hooks import pytest_collect_file, pytest_addoption, pytest_addhooks
 from .util import add_parser_options
 
-__all__ = ["pytest_addoption", "pytest_collect_file", "add_parser_options"]
+__all__ = ["pytest_addoption", "pytest_collect_file", "pytest_addhooks", "add_parser_options"]
diff --git a/tavern/testutils/pytesthook/hooks.py b/tavern/testutils/pytesthook/hooks.py
index 4d991dd1f..d45f477c1 100644
--- a/tavern/testutils/pytesthook/hooks.py
+++ b/tavern/testutils/pytesthook/hooks.py
@@ -54,3 +54,10 @@ def pytest_collect_file(parent, path):
         return YamlFile(path, parent)
 
     return None
+
+
+def pytest_addhooks(pluginmanager):
+    """Add our custom tavern hooks"""
+    from . import newhooks
+
+    pluginmanager.add_hookspecs(newhooks)
diff --git a/tavern/testutils/pytesthook/item.py b/tavern/testutils/pytesthook/item.py
index 0c055f4d2..89e593993 100644
--- a/tavern/testutils/pytesthook/item.py
+++ b/tavern/testutils/pytesthook/item.py
@@ -137,6 +137,8 @@ def runtest(self):
 
         load_plugins(self.global_cfg)
 
+        self.global_cfg["tavern_internal"] = {"pytest_hook_caller": self.config.hook}
+
         # INTERNAL
         # NOTE - now that we can 'mark' tests, we could use pytest.mark.xfail
         # instead. This doesn't differentiate between an error in verification
@@ -144,11 +146,18 @@ def runtest(self):
         xfail = self.spec.get("_xfail", False)
 
         try:
-            verify_tests(self.spec)
-
             fixture_values = self._load_fixture_values()
             self.global_cfg["variables"].update(fixture_values)
 
+            self.global_cfg["tavern_internal"][
+                "pytest_hook_caller"
+            ].pytest_tavern_before_every_test_run(
+                test_dict=self.spec,
+                variables=self.global_cfg["variables"]
+            )
+
+            verify_tests(self.spec)
+
             run_test(self.path, self.spec, self.global_cfg)
         except exceptions.BadSchemaError:
             if xfail == "verify":
diff --git a/tavern/testutils/pytesthook/newhooks.py b/tavern/testutils/pytesthook/newhooks.py
new file mode 100644
index 000000000..762724bb6
--- /dev/null
+++ b/tavern/testutils/pytesthook/newhooks.py
@@ -0,0 +1,19 @@
+# pylint: disable=unused-argument
+
+
+def pytest_tavern_before_every_test_run(test_dict, variables):
+    """Called:
+
+    - directly after fixtures are loaded for a test
+    - directly before verifying the schema of the file
+    - Before formatting is done on values
+    - After fixtures have been resolved
+    - After global configuration has been loaded
+    - After plugins have been loaded
+
+    Modify the test in-place if you want to do something to it.
+
+    Args:
+        test_dict (dict): Test to run
+        variables (dict): Available variables
+    """
diff --git a/tests/unit/conftest.py b/tests/unit/conftest.py
index 3a6a1a50e..6c0d7bd84 100644
--- a/tests/unit/conftest.py
+++ b/tests/unit/conftest.py
@@ -1,3 +1,4 @@
+from mock import Mock
 import pytest
 
 
@@ -13,6 +14,7 @@ def fix_example_includes():
         },
         "backends": {"mqtt": "paho-mqtt", "http": "requests"},
         "strict": True,
+        "tavern_internal": {"pytest_hook_caller": Mock()},
     }
 
     return includes.copy()