Add pytest-mock to the dev dependencies

poetry.lock

@@ -1425,6 +1425,20 @@ python-versions = "*"
 [package.dependencies]
 pytest = ">=2.6.0"
 
+[[package]]
+name = "pytest-mock"
+version = "3.5.1"
+description = "Thin-wrapper around the mock package for easier use with pytest"
+category = "dev"
+optional = false
+python-versions = ">=3.5"
+
+[package.dependencies]
+pytest = ">=5.0"
+
+[package.extras]
+dev = ["pre-commit", "tox", "pytest-asyncio"]
+
 [[package]]
 name = "pytest-randomly"
 version = "3.5.0"
@@ -1954,7 +1968,7 @@ research = ["jupyterlab", "nb_black", "numpy", "pytz"]
 [metadata]
 lock-version = "1.1"
 python-versions = "^3.8"
-content-hash = "5493dc22f056cf2845ac6bd480c55092b1ceca8038312a551cad9fb76761b77a"
+content-hash = "1a67cb850c9d8b35104d7429caf8f54c3fa0a2888ab4d8f54dbc3901afb14717"
 
 [metadata.files]
 alabaster = [
@@ -2707,6 +2721,10 @@ pytest-cov = [
 pytest-env = [
     {file = "pytest-env-0.6.2.tar.gz", hash = "sha256:7e94956aef7f2764f3c147d216ce066bf6c42948bb9e293169b1b1c880a580c2"},
 ]
+pytest-mock = [
+    {file = "pytest-mock-3.5.1.tar.gz", hash = "sha256:a1e2aba6af9560d313c642dae7e00a2a12b022b80301d9d7fc8ec6858e1dd9fc"},
+    {file = "pytest_mock-3.5.1-py3-none-any.whl", hash = "sha256:379b391cfad22422ea2e252bdfc008edd08509029bcde3c25b2c0bd741e0424e"},
+]
 pytest-randomly = [
     {file = "pytest-randomly-3.5.0.tar.gz", hash = "sha256:440cec143fd9b0adeb072006c71e0294402a2bc2ccd08079c2341087ba4cf2d1"},
     {file = "pytest_randomly-3.5.0-py3-none-any.whl", hash = "sha256:9db10d160237f3f8ee60cef72e4cb9ea88d2893c9dd5c8aa334b060cdeb67c3a"},

pyproject.toml

@@ -81,6 +81,7 @@ packaging = "^20.4"  # used to test the packaged version
 pytest = "^6.0.1"
 pytest-cov = "^2.10.0"
 pytest-env = "^0.6.2"
+pytest-mock = "^3.5.1"
 pytest-randomly = "^3.5.0"
 xdoctest = { version="^0.13.0", extras=["optional"] }