fix(diagnostics): never send diagnostics from test environments

src/mcpcat/modules/diagnostics.py

@@ -9,7 +9,9 @@
 ``~/mcpcat.log`` is unaffected.
 
 On by default; opt out via ``MCPCatOptions(disable_diagnostics=True)`` or the
-``DISABLE_DIAGNOSTICS`` env var. Nothing here ever throws into the host, and the
+``DISABLE_DIAGNOSTICS`` env var. Auto-disabled in test environments
+(``PYTEST_CURRENT_TEST`` / ``PYTEST_VERSION`` set) unless explicitly force-enabled
+with ``DISABLE_DIAGNOSTICS=false``. Nothing here ever throws into the host, and the
 fire-and-forget HTTP export runs on a daemon thread so it never blocks process exit.
 
 Override the collector with ``DIAGNOSTICS_ENDPOINT`` / ``DIAGNOSTICS_TOKEN``.
@@ -75,19 +77,40 @@ def _resolve_token() -> str:
         return DEFAULT_DIAGNOSTICS_TOKEN
 
 
-def _env_disabled() -> bool:
+def _is_test_environment() -> bool:
+    """True when running under pytest (``PYTEST_CURRENT_TEST`` / ``PYTEST_VERSION``).
+
+    Diagnostics auto-disable here so no test suite — ours or a consumer's — ever
+    ships OTLP metadata to the live collector. Never throws.
+    """
+    try:
+        return bool(
+            os.environ.get("PYTEST_CURRENT_TEST") or os.environ.get("PYTEST_VERSION")
+        )
+    except Exception:
+        return False
+
+
+def _env_diagnostics_flag() -> str:
     """Interpret ``DISABLE_DIAGNOSTICS`` by value, not mere presence.
 
-    ``false`` / ``0`` / ``no`` / ``off`` / empty (and whitespace) stay enabled;
-    anything else disables. Mirrors the ``MCPCAT_DEBUG_MODE`` idiom in logging.py.
+    Returns one of:
+    - ``"unset"``: env var unset, empty, or whitespace-only (default behavior).
+    - ``"force-enabled"``: ``false`` / ``0`` / ``no`` / ``off`` — a deliberate
+      opt-in that overrides the test-environment auto-disable.
+    - ``"disabled"``: anything else disables diagnostics.
+
+    Mirrors the ``MCPCAT_DEBUG_MODE`` idiom in logging.py.
     """
     try:
         raw = os.environ.get("DISABLE_DIAGNOSTICS")
-        if not raw:
-            return False
-        return raw.strip().lower() not in ("false", "0", "no", "off", "")
+        if not raw or not raw.strip():
+            return "unset"
+        if raw.strip().lower() in ("false", "0", "no", "off"):
+            return "force-enabled"
+        return "disabled"
     except Exception:
-        return False
+        return "unset"
 
 
 # --- Record construction ------------------------------------------------------
@@ -256,7 +279,15 @@ def init_diagnostics(project_id: str | None, disabled: bool = False) -> None:
         if _initialized:
             return
         _initialized = True
-        _enabled = (not disabled) and not _env_disabled()
+        # Off when opted out (option or env), and off in test environments unless
+        # explicitly force-enabled (DISABLE_DIAGNOSTICS=false) — so no test run,
+        # ours or a consumer's, ever ships diagnostics to the live collector.
+        flag = _env_diagnostics_flag()
+        _enabled = (
+            (not disabled)
+            and flag != "disabled"
+            and (flag == "force-enabled" or not _is_test_environment())
+        )
         if not _enabled:
             return
         _static_attributes = _build_static_attributes(project_id)

src/mcpcat/types.py

@@ -179,8 +179,10 @@ class MCPCatOptions:
     stateless: bool | None = None
     # Disables MCPCat's internal SDK diagnostics — anonymous, metadata-only
     # setup/error reporting used to detect failed installs. On by default; also
-    # disable-able via the DISABLE_DIAGNOSTICS env var. Never sends event
-    # payloads or user data; the local ~/mcpcat.log is unaffected.
+    # disable-able via the DISABLE_DIAGNOSTICS env var. Automatically disabled in
+    # test environments (PYTEST_CURRENT_TEST / PYTEST_VERSION set) so test suites
+    # never send anything; set DISABLE_DIAGNOSTICS=false to re-enable there. Never
+    # sends event payloads or user data; the local ~/mcpcat.log is unaffected.
     disable_diagnostics: bool = False
     # Callback invoked on every auto-captured event (initialize, tools/list,
     # tools/call) to attach string key-value tags. Tags are intended for

tests/conftest.py

@@ -0,0 +1,7 @@
+import os
+
+# Belt-and-suspenders: force diagnostics off before any test imports/runs, so no
+# test ordering or future change to the auto-disable detection can ever ship OTLP
+# diagnostics to the live collector from our own suite. Diagnostics-specific tests
+# opt back in explicitly with DISABLE_DIAGNOSTICS=false plus mocked HTTP.
+os.environ["DISABLE_DIAGNOSTICS"] = "true"

tests/test_diagnostics_attributes.py

@@ -8,7 +8,8 @@
 @pytest.fixture(autouse=True)
 def reset(monkeypatch):
     diagnostics._reset_diagnostics_for_test()
-    monkeypatch.delenv("DISABLE_DIAGNOSTICS", raising=False)
+    # Force-enable past the test-environment auto-disable; HTTP is mocked.
+    monkeypatch.setenv("DISABLE_DIAGNOSTICS", "false")
     yield
     diagnostics._reset_diagnostics_for_test()
 

tests/test_diagnostics_auth.py

@@ -11,7 +11,8 @@
 @pytest.fixture(autouse=True)
 def reset(monkeypatch):
     diagnostics._reset_diagnostics_for_test()
-    monkeypatch.delenv("DISABLE_DIAGNOSTICS", raising=False)
+    # Force-enable past the test-environment auto-disable; HTTP is mocked.
+    monkeypatch.setenv("DISABLE_DIAGNOSTICS", "false")
     monkeypatch.delenv("DIAGNOSTICS_TOKEN", raising=False)
     yield
     diagnostics._reset_diagnostics_for_test()

tests/test_diagnostics_export.py

@@ -11,7 +11,8 @@
 @pytest.fixture(autouse=True)
 def reset(monkeypatch):
     diagnostics._reset_diagnostics_for_test()
-    monkeypatch.delenv("DISABLE_DIAGNOSTICS", raising=False)
+    # Force-enable past the test-environment auto-disable; HTTP is mocked.
+    monkeypatch.setenv("DISABLE_DIAGNOSTICS", "false")
     monkeypatch.delenv("DIAGNOSTICS_ENDPOINT", raising=False)
     yield
     diagnostics._reset_diagnostics_for_test()

tests/test_diagnostics_integration.py

@@ -11,7 +11,8 @@
 @pytest.fixture(autouse=True)
 def reset(monkeypatch):
     diagnostics._reset_diagnostics_for_test()
-    monkeypatch.delenv("DISABLE_DIAGNOSTICS", raising=False)
+    # Force-enable past the test-environment auto-disable; HTTP is mocked.
+    monkeypatch.setenv("DISABLE_DIAGNOSTICS", "false")
     yield
     diagnostics._reset_diagnostics_for_test()
 

tests/test_diagnostics_optout.py

@@ -1,4 +1,10 @@
-"""Tests for diagnostics opt-out (option + DISABLE_DIAGNOSTICS env var)."""
+"""Tests for diagnostics opt-out (option + DISABLE_DIAGNOSTICS env var).
+
+Diagnostics auto-disable in test environments (PYTEST_CURRENT_TEST /
+PYTEST_VERSION set). To exercise the "enabled by default" behavior we simulate a
+non-test environment by deleting those markers; to exercise the auto-disable we
+set just the relevant marker.
+"""
 
 import pytest
 
@@ -8,12 +14,21 @@
 @pytest.fixture(autouse=True)
 def reset(monkeypatch):
     diagnostics._reset_diagnostics_for_test()
-    monkeypatch.delenv("DISABLE_DIAGNOSTICS", raising=False)
+    # Force-enable past the test-environment auto-disable; HTTP stays unused here.
+    monkeypatch.setenv("DISABLE_DIAGNOSTICS", "false")
     yield
     diagnostics._reset_diagnostics_for_test()
 
 
-def test_enabled_by_default():
+def _simulate_non_test_env(monkeypatch):
+    """Make _is_test_environment() report False for default-enabled behavior."""
+    monkeypatch.delenv("PYTEST_CURRENT_TEST", raising=False)
+    monkeypatch.delenv("PYTEST_VERSION", raising=False)
+    monkeypatch.delenv("DISABLE_DIAGNOSTICS", raising=False)
+
+
+def test_enabled_by_default(monkeypatch):
+    _simulate_non_test_env(monkeypatch)
     diagnostics.init_diagnostics("proj_1")
     assert diagnostics.is_diagnostics_enabled() is True
 
@@ -30,9 +45,39 @@ def test_disabled_via_env(monkeypatch, value):
     assert diagnostics.is_diagnostics_enabled() is False
 
 
-@pytest.mark.parametrize("value", ["false", "0", "no", "off", "  "])
-def test_stays_enabled_for_falsy_values(monkeypatch, value):
-    """The Kashish case: a value-interpreted env var, not presence-based."""
+@pytest.mark.parametrize("value", ["false", "0", "no", "off"])
+def test_falsy_env_force_enables(monkeypatch, value):
+    """Explicit falsy values are a deliberate opt-in, even under pytest."""
     monkeypatch.setenv("DISABLE_DIAGNOSTICS", value)
     diagnostics.init_diagnostics("proj_1")
     assert diagnostics.is_diagnostics_enabled() is True
+
+
+def test_whitespace_is_treated_as_unset(monkeypatch):
+    """Whitespace-only is unset, so default behavior applies (enabled outside tests)."""
+    _simulate_non_test_env(monkeypatch)
+    monkeypatch.setenv("DISABLE_DIAGNOSTICS", "  ")
+    diagnostics.init_diagnostics("proj_1")
+    assert diagnostics.is_diagnostics_enabled() is True
+
+
+def test_disabled_by_default_when_pytest_current_test_set(monkeypatch):
+    _simulate_non_test_env(monkeypatch)
+    monkeypatch.setenv("PYTEST_CURRENT_TEST", "some_test (call)")
+    diagnostics.init_diagnostics("proj_1")
+    assert diagnostics.is_diagnostics_enabled() is False
+
+
+def test_disabled_by_default_when_pytest_version_set(monkeypatch):
+    _simulate_non_test_env(monkeypatch)
+    monkeypatch.setenv("PYTEST_VERSION", "9.0.2")
+    diagnostics.init_diagnostics("proj_1")
+    assert diagnostics.is_diagnostics_enabled() is False
+
+
+def test_disable_false_force_enables_in_test_environment(monkeypatch):
+    """DISABLE_DIAGNOSTICS=false overrides the test-environment auto-disable."""
+    monkeypatch.setenv("PYTEST_CURRENT_TEST", "some_test (call)")
+    monkeypatch.setenv("DISABLE_DIAGNOSTICS", "false")
+    diagnostics.init_diagnostics("proj_1")
+    assert diagnostics.is_diagnostics_enabled() is True

tests/test_diagnostics_test_env.py

@@ -0,0 +1,43 @@
+"""Regression: diagnostics must auto-disable inside test environments.
+
+Ports MCPCat/mcpcat-typescript-sdk#44 to Python. A pytest run must never ship
+OTLP diagnostics to the live collector, even when a test calls ``track()`` with
+default options and no ``DISABLE_DIAGNOSTICS`` override. Consumers of the SDK get
+this protection for free; explicit ``DISABLE_DIAGNOSTICS=false`` opts back in.
+"""
+
+from unittest.mock import patch
+
+import pytest
+
+import mcpcat
+from mcpcat.modules import diagnostics
+
+
+@pytest.fixture(autouse=True)
+def reset():
+    diagnostics._reset_diagnostics_for_test()
+    yield
+    diagnostics._reset_diagnostics_for_test()
+
+
+def test_track_does_not_enable_diagnostics_in_pytest(monkeypatch):
+    # Simulate a consumer's test suite: no explicit opt-out in the environment.
+    monkeypatch.delenv("DISABLE_DIAGNOSTICS", raising=False)
+
+    with patch("mcpcat.modules.diagnostics.requests.post") as mock_post:
+        # track() runs init_diagnostics before validating the server, so even
+        # the error path would latch diagnostics on without the guard.
+        with pytest.raises(TypeError):
+            mcpcat.track(object(), "proj_test_env")
+
+        assert diagnostics.is_diagnostics_enabled() is False
+        diagnostics.flush_diagnostics()
+        mock_post.assert_not_called()
+
+
+def test_disable_diagnostics_false_force_enables_under_pytest(monkeypatch):
+    # Explicit opt-in overrides the test-environment auto-disable.
+    monkeypatch.setenv("DISABLE_DIAGNOSTICS", "false")
+    diagnostics.init_diagnostics("proj_test_env")
+    assert diagnostics.is_diagnostics_enabled() is True