feat: Support for disabling ANSI color escape codes via the `NO_COLOR…

…` environment variable or the `--no-color` CLI option

Ref: #1153

docs/changelog.rst

@@ -4,6 +4,10 @@ Changelog
 `Unreleased`_ - TBD
 -------------------
 
+**Added**
+
+- Support for disabling ANSI color escape codes via the `NO_COLOR <https://no-color.org/>` environment variable or the ``--no-color`` CLI option. `#1153`_
+
 **Changed**
 
 - Generate valid header values for Bearer auth by construction rather than by filtering.
@@ -1849,6 +1853,7 @@ Deprecated
 .. _0.3.0: https://github.com/schemathesis/schemathesis/compare/v0.2.0...v0.3.0
 .. _0.2.0: https://github.com/schemathesis/schemathesis/compare/v0.1.0...v0.2.0
 
+.. _#1153: https://github.com/schemathesis/schemathesis/issues/1153
 .. _#1134: https://github.com/schemathesis/schemathesis/issues/1134
 .. _#1121: https://github.com/schemathesis/schemathesis/issues/1121
 .. _#1100: https://github.com/schemathesis/schemathesis/issues/1100

docs/cli.rst

@@ -46,6 +46,8 @@ loaded API schema, processed operations, found errors, and used checks.
 
 By default, Schemathesis refuses to work with schemas that do not conform to the Open API spec, but you can disable this behavior with ``--validate-schema=false``.
 
+.. note:: Schemathesis supports colorless output via the `NO_COLOR <https://no-color.org/>` environment variable or the ``--no-color`` CLI option.
+
 Testing specific operations
 ---------------------------
 

src/schemathesis/cli/__init__.py

@@ -450,8 +450,11 @@ def __init__(self, *args: Any, group: ParameterGroup, **kwargs: Any):
     cls=GroupedOption,
     group=ParameterGroup.hypothesis,
 )
+@click.option("--no-color", help="Disable ANSI color escape codes.", type=bool, is_flag=True)
 @click.option("--verbosity", "-v", help="Reduce verbosity of error output.", count=True)
+@click.pass_context
 def run(
+    ctx: click.Context,
     schema: str,
     auth: Optional[Tuple[str, str]],
     auth_type: str,
@@ -491,12 +494,14 @@ def run(
     hypothesis_seed: Optional[int] = None,
     hypothesis_verbosity: Optional[hypothesis.Verbosity] = None,
     verbosity: int = 0,
+    no_color: bool = False,
 ) -> None:
     """Perform schemathesis test against an API specified by SCHEMA.
 
     SCHEMA must be a valid URL or file path pointing to an Open API / Swagger specification.
     """
     # pylint: disable=too-many-locals
+    maybe_disable_color(ctx, no_color)
     check_auth(auth, headers)
     selected_targets = tuple(target for target in targets_module.ALL_TARGETS if target.__name__ in targets)
 
@@ -822,18 +827,23 @@ def execute(
 @click.option("--status", help="Status of interactions to replay.", type=str)
 @click.option("--uri", help="A regexp that filters interactions by their request URI.", type=str)
 @click.option("--method", help="A regexp that filters interactions by their request method.", type=str)
+@click.option("--no-color", help="Disable ANSI color escape codes.", type=bool, is_flag=True)
+@click.pass_context
 def replay(
+    ctx: click.Context,
     cassette_path: str,
     id_: Optional[str],
     status: Optional[str] = None,
     uri: Optional[str] = None,
     method: Optional[str] = None,
+    no_color: bool = False,
 ) -> None:
     """Replay a cassette.
 
     Cassettes in VCR-compatible format can be replayed.
     For example, ones that are recorded with ``store-network-log`` option of `schemathesis run` command.
     """
+    maybe_disable_color(ctx, no_color)
     click.secho(f"{bold('Replaying cassette')}: {cassette_path}")
     with open(cassette_path) as fd:
         cassette = yaml.load(fd, Loader=SafeLoader)
@@ -849,6 +859,11 @@ def bold(message: str) -> str:
     return click.style(message, bold=True)
 
 
+def maybe_disable_color(ctx: click.Context, no_color: bool) -> None:
+    if no_color or "NO_COLOR" in os.environ:
+        ctx.color = False
+
+
 @HookDispatcher.register_spec([HookScope.GLOBAL])
 def after_init_cli_run_handlers(
     context: HookContext, handlers: List[EventHandler], execution_context: ExecutionContext

test/cli/test_commands.py

@@ -277,6 +277,7 @@ def test_commands_run_help(cli):
         "  --force-schema-version [20|30]  Force Schemathesis to parse the input schema",
         "                                  with the specified spec version.",
         "",
+        "  --no-color                      Disable ANSI color escape codes.",
         "  -v, --verbosity                 Reduce verbosity of error output.",
         "  -h, --help                      Show this message and exit.",
     ]
@@ -1910,3 +1911,17 @@ def test_response_payload_encoding(cli, cli_args):
     assert result.exit_code == ExitCode.TESTS_FAILED, result.stdout
     # Then it should be displayed according its actual encoding
     assert "Response payload: `Тест`" in result.stdout.splitlines()
+
+
+@pytest.mark.parametrize("kind", ("env_var", "arg"))
+@pytest.mark.parametrize("openapi_version", (OpenAPIVersion("3.0"),))
+@pytest.mark.operations("success")
+def test_no_color(monkeypatch, cli, schema_url, kind):
+    args = (schema_url,)
+    if kind == "env_var":
+        monkeypatch.setenv("NO_COLOR", "1")
+    if kind == "arg":
+        args += ("--no-color",)
+    result = cli.run(*args, color=True)
+    assert result.exit_code == ExitCode.OK, result.stdout
+    assert "[1m" not in result.stdout