From 78d6633d32f04edd4c0cc93baea988fa05d75555 Mon Sep 17 00:00:00 2001
From: Max Isbey <224885523+maxisbey@users.noreply.github.com>
Date: Fri, 16 Jan 2026 15:45:37 +0100
Subject: [PATCH] ci: add strict-no-cover to detect unnecessary coverage
 pragmas

Add strict-no-cover from pydantic to CI pipeline. This tool identifies
`# pragma: no cover` comments on lines that are actually covered by
tests, helping keep coverage pragmas accurate.

Changes:
- Add strict-no-cover as dev dependency (installed from git)
- Add `pragma: lax no cover` to coverage exclude_lines for partial coverage
- Add CI step to run strict-no-cover after coverage report
---
 .github/workflows/shared.yml |  3 +++
 pyproject.toml               |  3 +++
 uv.lock                      | 11 +++++++++++
 3 files changed, 17 insertions(+)

diff --git a/.github/workflows/shared.yml b/.github/workflows/shared.yml
index 3ace33a09c..c37311b2a3 100644
--- a/.github/workflows/shared.yml
+++ b/.github/workflows/shared.yml
@@ -62,6 +62,9 @@ jobs:
           uv run --frozen --no-sync coverage combine
           uv run --frozen --no-sync coverage report
 
+      - name: Check for unnecessary no cover pragmas
+        run: uv run --frozen --no-sync strict-no-cover
+
   readme-snippets:
     runs-on: ubuntu-latest
     steps:
diff --git a/pyproject.toml b/pyproject.toml
index e1b175c769..0895a29247 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -67,6 +67,7 @@ dev = [
     "dirty-equals>=0.9.0",
     "coverage[toml]>=7.13.1",
     "pillow>=12.0",
+    "strict-no-cover",
 ]
 docs = [
     "mkdocs>=1.6.1",
@@ -154,6 +155,7 @@ members = ["examples/clients/*", "examples/servers/*", "examples/snippets"]
 
 [tool.uv.sources]
 mcp = { workspace = true }
+strict-no-cover = { git = "https://github.com/pydantic/strict-no-cover" }
 
 [tool.pytest.ini_options]
 log_cli = true
@@ -207,6 +209,7 @@ ignore_errors = true
 precision = 2
 exclude_lines = [
     "pragma: no cover",
+    "pragma: lax no cover",
     "if TYPE_CHECKING:",
     "@overload",
     "raise NotImplementedError",
diff --git a/uv.lock b/uv.lock
index d2a5158630..70f2d0e4f7 100644
--- a/uv.lock
+++ b/uv.lock
@@ -764,6 +764,7 @@ dev = [
     { name = "pytest-pretty" },
     { name = "pytest-xdist" },
     { name = "ruff" },
+    { name = "strict-no-cover" },
     { name = "trio" },
 ]
 docs = [
@@ -811,6 +812,7 @@ dev = [
     { name = "pytest-pretty", specifier = ">=1.2.0" },
     { name = "pytest-xdist", specifier = ">=3.6.1" },
     { name = "ruff", specifier = ">=0.8.5" },
+    { name = "strict-no-cover", git = "https://github.com/pydantic/strict-no-cover" },
     { name = "trio", specifier = ">=0.26.2" },
 ]
 docs = [
@@ -2533,6 +2535,15 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/51/da/545b75d420bb23b5d494b0517757b351963e974e79933f01e05c929f20a6/starlette-0.49.1-py3-none-any.whl", hash = "sha256:d92ce9f07e4a3caa3ac13a79523bd18e3bc0042bb8ff2d759a8e7dd0e1859875", size = 74175, upload-time = "2025-10-28T17:34:09.13Z" },
 ]
 
+[[package]]
+name = "strict-no-cover"
+version = "0.1.1"
+source = { git = "https://github.com/pydantic/strict-no-cover#7fc59da2c4dff919db2095a0f0e47101b657131d" }
+dependencies = [
+    { name = "pydantic", version = "2.11.7", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version < '3.14'" },
+    { name = "pydantic", version = "2.12.5", source = { registry = "https://pypi.org/simple" }, marker = "python_full_version >= '3.14'" },
+]
+
 [[package]]
 name = "tomli"
 version = "2.2.1"