Get baseline 100% clean coverage

.github/workflows/shared.yml

@@ -55,8 +55,11 @@ jobs:
       - name: Install the project
         run: uv sync ${{ matrix.dep-resolution.install-flags }} --all-extras --python ${{ matrix.python-version }}
 
-      - name: Run pytest
-        run: uv run ${{ matrix.dep-resolution.install-flags }} --no-sync pytest
+      - name: Run pytest with coverage
+        run: |
+          uv run ${{ matrix.dep-resolution.install-flags }} --no-sync coverage run -m pytest
+          uv run ${{ matrix.dep-resolution.install-flags }} --no-sync coverage combine
+          uv run ${{ matrix.dep-resolution.install-flags }} --no-sync coverage report
         env:
           UV_RESOLUTION: ${{ matrix.dep-resolution.name == 'lowest-direct' && 'lowest-direct' || 'highest' }}
 

pyproject.toml

@@ -60,6 +60,7 @@ dev = [
     "pytest-pretty>=1.2.0",
     "inline-snapshot>=0.23.0",
     "dirty-equals>=0.9.0",
+    "coverage[toml]==7.10.7",
 ]
 docs = [
     "mkdocs>=1.6.1",
@@ -168,3 +169,40 @@ MD033 = false    # no-inline-html Inline HTML
 MD041 = false    # first-line-heading/first-line-h1
 MD046 = false    # indented-code-blocks
 MD059 = false    # descriptive-link-text
+
+# https://coverage.readthedocs.io/en/latest/config.html#run
+[tool.coverage.run]
+branch = true
+patch = ["subprocess"]
+concurrency = ["multiprocessing", "thread"]
+source = ["src", "tests"]
+relative_files = true
+omit = [
+    "src/mcp/client/__main__.py",
+    "src/mcp/server/__main__.py",
+    "src/mcp/os/posix/utilities.py",
+    "src/mcp/os/win32/utilities.py",
+]
+
+# https://coverage.readthedocs.io/en/latest/config.html#report
+[tool.coverage.report]
+fail_under = 100
+skip_covered = true
+show_missing = true
+ignore_errors = true
+precision = 2
+exclude_lines = [
+    "pragma: no cover",
+    "if TYPE_CHECKING:",
+    "@overload",
+    "raise NotImplementedError",
+    "^\\s*\\.\\.\\.\\s*$",
+]
+
+# https://coverage.readthedocs.io/en/latest/config.html#paths
+[tool.coverage.paths]
+source = [
+    "src/",
+    "/home/runner/work/python-sdk/python-sdk/src/",
+    'D:\a\python-sdk\python-sdk\src',
+]

scripts/test

@@ -0,0 +1,7 @@
+#!/bin/sh
+
+set -ex
+
+uv run --frozen coverage run -m pytest -n auto $@
+uv run --frozen coverage combine
+uv run --frozen coverage report

src/mcp/cli/__init__.py

@@ -2,5 +2,5 @@
 
 from .cli import app
 
-if __name__ == "__main__":
+if __name__ == "__main__":  # pragma: no cover
     app()

src/mcp/cli/claude.py

@@ -14,7 +14,7 @@
 MCP_PACKAGE = "mcp[cli]"
 
 
-def get_claude_config_path() -> Path | None:
+def get_claude_config_path() -> Path | None:  # pragma: no cover
     """Get the Claude config directory based on platform."""
     if sys.platform == "win32":
         path = Path(Path.home(), "AppData", "Roaming", "Claude")
@@ -33,7 +33,7 @@ def get_claude_config_path() -> Path | None:
 def get_uv_path() -> str:
     """Get the full path to the uv executable."""
     uv_path = shutil.which("uv")
-    if not uv_path:
+    if not uv_path:  # pragma: no cover
         logger.error(
             "uv executable not found in PATH, falling back to 'uv'. Please ensure uv is installed and in your PATH"
         )
@@ -65,14 +65,14 @@ def update_claude_config(
     """
     config_dir = get_claude_config_path()
     uv_path = get_uv_path()
-    if not config_dir:
+    if not config_dir:  # pragma: no cover
         raise RuntimeError(
             "Claude Desktop config directory not found. Please ensure Claude Desktop"
             " is installed and has been run at least once to initialize its config."
         )
 
     config_file = config_dir / "claude_desktop_config.json"
-    if not config_file.exists():
+    if not config_file.exists():  # pragma: no cover
         try:
             config_file.write_text("{}")
         except Exception:
@@ -90,7 +90,7 @@ def update_claude_config(
             config["mcpServers"] = {}
 
         # Always preserve existing env vars and merge with new ones
-        if server_name in config["mcpServers"] and "env" in config["mcpServers"][server_name]:
+        if server_name in config["mcpServers"] and "env" in config["mcpServers"][server_name]:  # pragma: no cover
             existing_env = config["mcpServers"][server_name]["env"]
             if env_vars:
                 # New vars take precedence over existing ones
@@ -103,22 +103,22 @@ def update_claude_config(
 
         # Collect all packages in a set to deduplicate
         packages = {MCP_PACKAGE}
-        if with_packages:
+        if with_packages:  # pragma: no cover
             packages.update(pkg for pkg in with_packages if pkg)
 
         # Add all packages with --with
         for pkg in sorted(packages):
             args.extend(["--with", pkg])
 
-        if with_editable:
+        if with_editable:  # pragma: no cover
             args.extend(["--with-editable", str(with_editable)])
 
         # Convert file path to absolute before adding to command
         # Split off any :object suffix first
         if ":" in file_spec:
             file_path, server_object = file_spec.rsplit(":", 1)
             file_spec = f"{Path(file_path).resolve()}:{server_object}"
-        else:
+        else:  # pragma: no cover
             file_spec = str(Path(file_spec).resolve())
 
         # Add fastmcp run command
@@ -127,7 +127,7 @@ def update_claude_config(
         server_config: dict[str, Any] = {"command": uv_path, "args": args}
 
         # Add environment variables if specified
-        if env_vars:
+        if env_vars:  # pragma: no cover
             server_config["env"] = env_vars
 
         config["mcpServers"][server_name] = server_config
@@ -138,7 +138,7 @@ def update_claude_config(
             extra={"config_file": str(config_file)},
         )
         return True
-    except Exception:
+    except Exception:  # pragma: no cover
         logger.exception(
             "Failed to update Claude config",
             extra={

src/mcp/cli/cli.py

@@ -13,20 +13,20 @@
 
 try:
     import typer
-except ImportError:
+except ImportError:  # pragma: no cover
     print("Error: typer is required. Install with 'pip install mcp[cli]'")
     sys.exit(1)
 
 try:
     from mcp.cli import claude
     from mcp.server.fastmcp.utilities.logging import get_logger
-except ImportError:
+except ImportError:  # pragma: no cover
     print("Error: mcp.server.fastmcp is not installed or not in PYTHONPATH")
     sys.exit(1)
 
 try:
     import dotenv
-except ImportError:
+except ImportError:  # pragma: no cover
     dotenv = None
 
 logger = get_logger("cli")
@@ -53,7 +53,7 @@ def _get_npx_command():
     return "npx"  # On Unix-like systems, just use npx
 
 
-def _parse_env_var(env_var: str) -> tuple[str, str]:
+def _parse_env_var(env_var: str) -> tuple[str, str]:  # pragma: no cover
     """Parse environment variable string in format KEY=VALUE."""
     if "=" not in env_var:
         logger.error(f"Invalid environment variable format: {env_var}. Must be KEY=VALUE")
@@ -77,7 +77,7 @@ def _build_uv_command(
 
     if with_packages:
         for pkg in with_packages:
-            if pkg:
+            if pkg:  # pragma: no cover
                 cmd.extend(["--with", pkg])
 
     # Add mcp run command
@@ -116,7 +116,7 @@ def _parse_file_path(file_spec: str) -> tuple[Path, str | None]:
     return file_path, server_object
 
 
-def _import_server(file: Path, server_object: str | None = None):
+def _import_server(file: Path, server_object: str | None = None):  # pragma: no cover
     """Import an MCP server from a file.
 
     Args:
@@ -209,7 +209,7 @@ def _check_server_object(server_object: Any, object_name: str):
 
 
 @app.command()
-def version() -> None:
+def version() -> None:  # pragma: no cover
     """Show the MCP version."""
     try:
         version = importlib.metadata.version("mcp")
@@ -243,7 +243,7 @@ def dev(
             help="Additional packages to install",
         ),
     ] = [],
-) -> None:
+) -> None:  # pragma: no cover
     """Run an MCP server with the MCP Inspector."""
     file, server_object = _parse_file_path(file_spec)
 
@@ -316,7 +316,7 @@ def run(
             help="Transport protocol to use (stdio or sse)",
         ),
     ] = None,
-) -> None:
+) -> None:  # pragma: no cover
     """Run an MCP server.
 
     The server can be specified in two ways:\n
@@ -411,7 +411,7 @@ def install(
             resolve_path=True,
         ),
     ] = None,
-) -> None:
+) -> None:  # pragma: no cover
     """Install an MCP server in the Claude desktop app.
 
     Environment variables are preserved once added and only updated if new values

src/mcp/client/auth/extensions/client_credentials.py

@@ -34,15 +34,15 @@ def to_assertion(self, with_audience_fallback: str | None = None) -> str:
             assertion = self.assertion
         else:
             if not self.jwt_signing_key:
-                raise OAuthFlowError("Missing signing key for JWT bearer grant")
+                raise OAuthFlowError("Missing signing key for JWT bearer grant")  # pragma: no cover
             if not self.issuer:
-                raise OAuthFlowError("Missing issuer for JWT bearer grant")
+                raise OAuthFlowError("Missing issuer for JWT bearer grant")  # pragma: no cover
             if not self.subject:
-                raise OAuthFlowError("Missing subject for JWT bearer grant")
+                raise OAuthFlowError("Missing subject for JWT bearer grant")  # pragma: no cover
 
             audience = self.audience if self.audience else with_audience_fallback
             if not audience:
-                raise OAuthFlowError("Missing audience for JWT bearer grant")
+                raise OAuthFlowError("Missing audience for JWT bearer grant")  # pragma: no cover
 
             now = int(time.time())
             claims: dict[str, Any] = {
@@ -83,22 +83,22 @@ def __init__(
 
     async def _exchange_token_authorization_code(
         self, auth_code: str, code_verifier: str, *, token_data: dict[str, Any] | None = None
-    ) -> httpx.Request:
+    ) -> httpx.Request:  # pragma: no cover
         """Build token exchange request for authorization_code flow."""
         token_data = token_data or {}
         if self.context.client_metadata.token_endpoint_auth_method == "private_key_jwt":
             self._add_client_authentication_jwt(token_data=token_data)
         return await super()._exchange_token_authorization_code(auth_code, code_verifier, token_data=token_data)
 
-    async def _perform_authorization(self) -> httpx.Request:
+    async def _perform_authorization(self) -> httpx.Request:  # pragma: no cover
         """Perform the authorization flow."""
         if "urn:ietf:params:oauth:grant-type:jwt-bearer" in self.context.client_metadata.grant_types:
             token_request = await self._exchange_token_jwt_bearer()
             return token_request
         else:
             return await super()._perform_authorization()
 
-    def _add_client_authentication_jwt(self, *, token_data: dict[str, Any]):
+    def _add_client_authentication_jwt(self, *, token_data: dict[str, Any]):  # pragma: no cover
         """Add JWT assertion for client authentication to token endpoint parameters."""
         if not self.jwt_parameters:
             raise OAuthTokenError("Missing JWT parameters for private_key_jwt flow")
@@ -120,11 +120,11 @@ def _add_client_authentication_jwt(self, *, token_data: dict[str, Any]):
     async def _exchange_token_jwt_bearer(self) -> httpx.Request:
         """Build token exchange request for JWT bearer grant."""
         if not self.context.client_info:
-            raise OAuthFlowError("Missing client info")
+            raise OAuthFlowError("Missing client info")  # pragma: no cover
         if not self.jwt_parameters:
-            raise OAuthFlowError("Missing JWT parameters")
+            raise OAuthFlowError("Missing JWT parameters")  # pragma: no cover
         if not self.context.oauth_metadata:
-            raise OAuthTokenError("Missing OAuth metadata")
+            raise OAuthTokenError("Missing OAuth metadata")  # pragma: no cover
 
         # We need to set the audience to the issuer identifier of the authorization server
         # https://datatracker.ietf.org/doc/html/draft-ietf-oauth-rfc7523bis-01#name-updates-to-rfc-7523
@@ -136,10 +136,10 @@ async def _exchange_token_jwt_bearer(self) -> httpx.Request:
             "assertion": assertion,
         }
 
-        if self.context.should_include_resource_param(self.context.protocol_version):
+        if self.context.should_include_resource_param(self.context.protocol_version):  # pragma: no branch
             token_data["resource"] = self.context.get_resource_url()
 
-        if self.context.client_metadata.scope:
+        if self.context.client_metadata.scope:  # pragma: no branch
             token_data["scope"] = self.context.client_metadata.scope
 
         token_url = self._get_token_endpoint()