feat: allow global retry_transient_errors setup

`retry_transient_errors` can now be set through the Gitlab instance and global configuration

Documentation for API usage has been updated and missing tests have been added.

3 files changed, 173 insertions, 7 deletions

diff --git a/tests/unit/conftest.py b/tests/unit/conftest.py
index 64df051..f58c77a 100644
--- a/tests/unit/conftest.py
+++ b/tests/unit/conftest.py
@@ -9,7 +9,18 @@ def gl():
         "http://localhost",
         private_token="private_token",
         ssl_verify=True,
-        api_version=4,
+        api_version="4",
+    )
+
+
+@pytest.fixture
+def gl_retry():
+    return gitlab.Gitlab(
+        "http://localhost",
+        private_token="private_token",
+        ssl_verify=True,
+        api_version="4",
+        retry_transient_errors=True,
     )
 
 
@@ -17,7 +28,7 @@ def gl():
 @pytest.fixture
 def gl_trailing():
     return gitlab.Gitlab(
-        "http://localhost/", private_token="private_token", api_version=4
+        "http://localhost/", private_token="private_token", api_version="4"
     )
 
 
diff --git a/tests/unit/test_config.py b/tests/unit/test_config.py
index cd61b8d..a62106b 100644
--- a/tests/unit/test_config.py
+++ b/tests/unit/test_config.py
@@ -86,6 +86,31 @@ per_page = 200
 """
 
 
+def global_retry_transient_errors(value: bool) -> str:
+    return u"""[global]
+default = one
+retry_transient_errors={}
+[one]
+url = http://one.url
+private_token = ABCDEF""".format(
+        value
+    )
+
+
+def global_and_gitlab_retry_transient_errors(
+    global_value: bool, gitlab_value: bool
+) -> str:
+    return u"""[global]
+    default = one
+    retry_transient_errors={global_value}
+    [one]
+    url = http://one.url
+    private_token = ABCDEF
+    retry_transient_errors={gitlab_value}""".format(
+        global_value=global_value, gitlab_value=gitlab_value
+    )
+
+
 @mock.patch.dict(os.environ, {"PYTHON_GITLAB_CFG": "/some/path"})
 def test_env_config_present():
     assert ["/some/path"] == config._env_config()
@@ -245,3 +270,48 @@ def test_config_user_agent(m_open, path_exists, config_string, expected_agent):
 
     cp = config.GitlabConfigParser()
     assert cp.user_agent == expected_agent
+
+
+@mock.patch("os.path.exists")
+@mock.patch("builtins.open")
+@pytest.mark.parametrize(
+    "config_string,expected",
+    [
+        pytest.param(valid_config, False, id="default_value"),
+        pytest.param(
+            global_retry_transient_errors(True), True, id="global_config_true"
+        ),
+        pytest.param(
+            global_retry_transient_errors(False), False, id="global_config_false"
+        ),
+        pytest.param(
+            global_and_gitlab_retry_transient_errors(False, True),
+            True,
+            id="gitlab_overrides_global_true",
+        ),
+        pytest.param(
+            global_and_gitlab_retry_transient_errors(True, False),
+            False,
+            id="gitlab_overrides_global_false",
+        ),
+        pytest.param(
+            global_and_gitlab_retry_transient_errors(True, True),
+            True,
+            id="gitlab_equals_global_true",
+        ),
+        pytest.param(
+            global_and_gitlab_retry_transient_errors(False, False),
+            False,
+            id="gitlab_equals_global_false",
+        ),
+    ],
+)
+def test_config_retry_transient_errors_when_global_config_is_set(
+    m_open, path_exists, config_string, expected
+):
+    fd = io.StringIO(config_string)
+    fd.close = mock.Mock(return_value=None)
+    m_open.return_value = fd
+
+    cp = config.GitlabConfigParser()
+    assert cp.retry_transient_errors == expected
diff --git a/tests/unit/test_gitlab_http_methods.py b/tests/unit/test_gitlab_http_methods.py
index f1bc9cd..5a3584e 100644
--- a/tests/unit/test_gitlab_http_methods.py
+++ b/tests/unit/test_gitlab_http_methods.py
@@ -30,7 +30,7 @@ def test_http_request(gl):
 def test_http_request_404(gl):
     @urlmatch(scheme="http", netloc="localhost", path="/api/v4/not_there", method="get")
     def resp_cont(url, request):
-        content = {"Here is wh it failed"}
+        content = {"Here is why it failed"}
         return response(404, content, {}, None, 5, request)
 
     with HTTMock(resp_cont):
@@ -38,6 +38,91 @@ def test_http_request_404(gl):
             gl.http_request("get", "/not_there")
 
 
+@pytest.mark.parametrize("status_code", [500, 502, 503, 504])
+def test_http_request_with_only_failures(gl, status_code):
+    call_count = 0
+
+    @urlmatch(scheme="http", netloc="localhost", path="/api/v4/projects", method="get")
+    def resp_cont(url, request):
+        nonlocal call_count
+        call_count += 1
+        return response(status_code, {"Here is why it failed"}, {}, None, 5, request)
+
+    with HTTMock(resp_cont):
+        with pytest.raises(GitlabHttpError):
+            gl.http_request("get", "/projects")
+
+    assert call_count == 1
+
+
+def test_http_request_with_retry_on_method_for_transient_failures(gl):
+    call_count = 0
+    calls_before_success = 3
+
+    @urlmatch(scheme="http", netloc="localhost", path="/api/v4/projects", method="get")
+    def resp_cont(url, request):
+        nonlocal call_count
+        call_count += 1
+        status_code = 200 if call_count == calls_before_success else 500
+        return response(
+            status_code,
+            {"Failure is the stepping stone to success"},
+            {},
+            None,
+            5,
+            request,
+        )
+
+    with HTTMock(resp_cont):
+        http_r = gl.http_request("get", "/projects", retry_transient_errors=True)
+
+        assert http_r.status_code == 200
+        assert call_count == calls_before_success
+
+
+def test_http_request_with_retry_on_class_for_transient_failures(gl_retry):
+    call_count = 0
+    calls_before_success = 3
+
+    @urlmatch(scheme="http", netloc="localhost", path="/api/v4/projects", method="get")
+    def resp_cont(url, request):
+        nonlocal call_count
+        call_count += 1
+        status_code = 200 if call_count == calls_before_success else 500
+        return response(
+            status_code,
+            {"Failure is the stepping stone to success"},
+            {},
+            None,
+            5,
+            request,
+        )
+
+    with HTTMock(resp_cont):
+        http_r = gl_retry.http_request("get", "/projects")
+
+        assert http_r.status_code == 200
+        assert call_count == calls_before_success
+
+
+def test_http_request_with_retry_on_class_and_method_for_transient_failures(gl_retry):
+    call_count = 0
+    calls_before_success = 3
+
+    @urlmatch(scheme="http", netloc="localhost", path="/api/v4/projects", method="get")
+    def resp_cont(url, request):
+        nonlocal call_count
+        call_count += 1
+        status_code = 200 if call_count == calls_before_success else 500
+        return response(status_code, {"Here is why it failed"}, {}, None, 5, request)
+
+    with HTTMock(resp_cont):
+        with pytest.raises(GitlabHttpError):
+            gl_retry.http_request("get", "/projects", retry_transient_errors=False)
+
+        assert call_count == 1
+
+
 def test_get_request(gl):
     @urlmatch(scheme="http", netloc="localhost", path="/api/v4/projects", method="get")
     def resp_cont(url, request):
@@ -66,7 +151,7 @@ def test_get_request_raw(gl):
 def test_get_request_404(gl):
     @urlmatch(scheme="http", netloc="localhost", path="/api/v4/not_there", method="get")
     def resp_cont(url, request):
-        content = {"Here is wh it failed"}
+        content = {"Here is why it failed"}
         return response(404, content, {}, None, 5, request)
 
     with HTTMock(resp_cont):
@@ -150,7 +235,7 @@ def test_post_request_404(gl):
         scheme="http", netloc="localhost", path="/api/v4/not_there", method="post"
     )
     def resp_cont(url, request):
-        content = {"Here is wh it failed"}
+        content = {"Here is why it failed"}
         return response(404, content, {}, None, 5, request)
 
     with HTTMock(resp_cont):
@@ -186,7 +271,7 @@ def test_put_request(gl):
 def test_put_request_404(gl):
     @urlmatch(scheme="http", netloc="localhost", path="/api/v4/not_there", method="put")
     def resp_cont(url, request):
-        content = {"Here is wh it failed"}
+        content = {"Here is why it failed"}
         return response(404, content, {}, None, 5, request)
 
     with HTTMock(resp_cont):
@@ -226,7 +311,7 @@ def test_delete_request_404(gl):
         scheme="http", netloc="localhost", path="/api/v4/not_there", method="delete"
     )
     def resp_cont(url, request):
-        content = {"Here is wh it failed"}
+        content = {"Here is why it failed"}
         return response(404, content, {}, None, 5, request)
 
     with HTTMock(resp_cont):