clang-tidy: resolve bugprone-unchecked-optional-access (#495)

`clang-tidy` does not recognize Catch2's `REQUIRE` macro as protecting
the target `std::optional` against non-existent-value access; use `//
NOLINT` to silence the warning.

`clang-tidy` correctly noted that there was a (theoretical) path to
unprotected access to an `std::optional`. We now throw an
`std::logic_error` and protect it from coverage validation as a `should
never happen` untestable case.

* Widen coverage exclusion to the full "can never happen" block

Author: greenc-FNAL

docs/dev/clang-tidy-fixes-2026-04.md

@@ -16,7 +16,8 @@
   - [PR #499](https://github.com/Framework-R-D/phlex/pull/499)
 - [x] [bugprone-throwing-static-initialization](https://clang.llvm.org/extra/clang-tidy/checks/bugprone/throwing-static-initialization.html) (7)
   - [PR #472](https://github.com/Framework-R-D/phlex/pull/472)
-- [ ] [bugprone-unchecked-optional-access](https://clang.llvm.org/extra/clang-tidy/checks/bugprone/unchecked-optional-access.html) (15)
+- [x] [bugprone-unchecked-optional-access](https://clang.llvm.org/extra/clang-tidy/checks/bugprone/unchecked-optional-access.html) (15)
+  - [PR #495](https://github.com/Framework-R-D/phlex/pull/495)
 - [ ] [cert-dcl50-cpp](https://clang.llvm.org/extra/clang-tidy/checks/cert/dcl50-cpp.html) (2)
 - [ ] [cert-err33-c](https://clang.llvm.org/extra/clang-tidy/checks/cert/err33-c.html) (4)
 - [ ] [cert-msc30-c](https://clang.llvm.org/extra/clang-tidy/checks/cert/msc30-c.html) (6)

plugins/python/src/modulewrap.cpp

@@ -1182,11 +1182,13 @@ static PyObject* sc_provide(py_phlex_source* src, PyObject* args, PyObject* kwds
   // translate and validate the output query
   auto opq = validate_query(output);
   if (!opq.has_value()) {
-    // validate_query will have set a python exception
-    std::string msg;
-    if (msg_from_py_error(msg, false)) {
-      throw std::runtime_error("output specification error: " + msg);
-    }
+    // LCOV_EXCL_START
+    // validate_query _will_ have set a python exception with details about the
+    //  error, so just propagate it as a C++ exception
+    std::string msg{"(unknown)"};
+    msg_from_py_error(msg, false);
+    throw std::runtime_error("output specification error: " + msg);
+    // LCOV_EXCL_STOP
   }
 
   // insert provider node (TODO: as in transform and observe, we'll leak the

test/form/form_basics_test.cpp

@@ -207,7 +207,8 @@ TEST_CASE("form::experimental::config tests", "[form]")
     cfg.addItem("prod1", "file1.root", 1);
 
     auto item = cfg.findItem("prod1");
-    REQUIRE(item.has_value());
+    REQUIRE(item);
+    // NOLINTNEXTLINE(bugprone-unchecked-optional-access) -- `REQUIRE` protects against incorrect access
     CHECK(item->product_name == "prod1");
 
     CHECK_FALSE(cfg.findItem("nonexistent").has_value());

test/identifier.cpp

@@ -33,6 +33,7 @@ TEST_CASE("Identifier from JSON", "[identifier]")
   boost::json::object parsed_json = boost::json::parse(R"( {"identifier": "b" } )").as_object();
   auto b_from_json = phlex::detail::value_if_exists(parsed_json, "identifier");
   REQUIRE(b_from_json);
+  // NOLINTNEXTLINE(bugprone-unchecked-optional-access) -- `REQUIRE` protects against incorrect access
   CHECK(b == *b_from_json);
 }