Fix pytest when source coverage is not used

The source coverage option may not be defined when running the tests
manually. The option existence should be checked before trying to get
it.

The `coverage` package dependency was also missing from the
`pyproject.toml`.

pyproject.toml

@@ -21,6 +21,7 @@ classifiers = [
 ]
 
 dependencies = [
+  "coverage",
   "colorama",
   "pyyaml",
   "python-dateutil",

src/e3/pytest.py

@@ -73,7 +73,7 @@ def env_protect(request: pytest.FixtureRequest) -> None:
 
     The fixture is enabled for all tests and does the following:
 
-    * store/restore env between each tests
+    * store/restore env between tests
     * create a temporary directory and do a cd to it before each
       test. The directory is automatically removed when test ends
     """
@@ -98,9 +98,14 @@ def restore_env() -> None:
 
 
 def pytest_configure(config: pytest.Config) -> None:
-    if config.getoption("e3") and config.getoption("cov_source"):
+    if (
+        hasattr(config.option, "e3")
+        and config.getoption("e3")
+        and hasattr(config.option, "cov_source")
+        and config.getoption("cov_source")
+    ):
         # When e3 plugin is activated, the report generated by pytest-cov
-        # should be deactivated to avoid duplicating the output. Also
+        # should be deactivated to avoid duplicating the output. Also,
         # some options set by e3 change the coverage, pytest-cov report is not
         # accurate in that case.
         cov = config.pluginmanager.getplugin("_cov")
@@ -122,7 +127,9 @@ def pytest_sessionfinish(session: pytest.Session, exitstatus: int) -> None:
         # test code.
         session.exitstatus = 3
 
-    if session.config.getoption("cov_source"):
+    if hasattr(session.config.option, "cov_source") and session.config.getoption(
+        "cov_source"
+    ):
         cov_file = str(session.config.rootpath / ".coverage")
         if session.config.getoption("e3_cov_rewrite"):
             origin_dir, new_dir = session.config.getoption("e3_cov_rewrite")
@@ -181,7 +188,7 @@ def fix_coverage_paths(origin_dir: str, new_dir: str, cov_db: str) -> None:
         .tox/py311-cov-xdist/lib/python3.11/site-packages/e3
     :param new_dir: path to the dir that should be visible instead of origin_dir
         e.g. src/
-    :param cov_db: path to the .coverage data base
+    :param cov_db: path to the .coverage database
     """
     paths = PathAliases()
     paths.add(origin_dir, new_dir)