Enable clang-tidy cognitive complexity checks

[Copilot]

readability-function-cognitive-complexity was disabled, leaving highly complex functions invisible to clang-tidy. This enables the check with a higher initial threshold and macro expansion ignored.

• clang-tidy configuration
  • Enables readability-function-cognitive-complexity.
  • Sets IgnoreMacros=true to avoid logging/registration macro noise.
  • Sets Threshold=50 as the initial enforcement level.

CheckOptions:
  - key: readability-function-cognitive-complexity.IgnoreMacros
    value: 'true'
  - key: readability-function-cognitive-complexity.Threshold
    value: '50'

• Baseline suppressions
  • Adds targeted NOLINTNEXTLINE(readability-function-cognitive-complexity) annotations for existing non-vendored functions currently above the threshold.
  • This establishes a clean baseline so new over-threshold functions are reported without requiring broad refactors in this PR.

[Copilot]

Pull request overview

Enables clang-tidy’s readability-function-cognitive-complexity check (previously disabled) with an initial higher threshold and macro-ignoring configuration, and establishes a baseline by adding targeted NOLINTNEXTLINE suppressions for existing over-threshold functions.

Changes:

• Enable readability-function-cognitive-complexity and configure it with IgnoreMacros=true and Threshold=50 in .clang-tidy.
• Add targeted NOLINTNEXTLINE(readability-function-cognitive-complexity) annotations to known complex functions/tests to keep the new check actionable immediately.

Custom instructions used:

• .github/copilot-instructions.md
• .github/instructions/reviewing.instructions.md

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
.clang-tidy	Enables and configures cognitive complexity checking with initial threshold + macro ignoring.
src/node/test/historical_queries.cpp	Suppresses existing over-threshold complexity in a TEST_CASE.
src/node/rpc/node_frontend.h	Suppresses existing over-threshold complexity in init_handlers().
src/node/rpc/frontend.h	Suppresses existing over-threshold complexity in process_command_inner().
src/node/rpc/file_serving_handlers.h	Suppresses existing over-threshold complexity in file-serving helper/initializer functions.
src/node/node_state.h	Suppresses existing over-threshold complexity in initiate_join_unsafe().
src/node/gov/handlers/service_state.h	Suppresses existing over-threshold complexity in handler registration.
src/node/gov/handlers/proposals.h	Suppresses existing over-threshold complexity in handler registration.
src/node/gov/handlers/acks.h	Suppresses existing over-threshold complexity in handler registration.
src/js/registry.cpp	Suppresses existing over-threshold complexity in JS request execution path.
src/indexing/test/indexing.cpp	Suppresses existing over-threshold complexity in a multi-threaded indexing test.
samples/apps/programmability/programmability.cpp	Suppresses existing over-threshold complexity in constructor/handler setup.
samples/apps/logging/logging.cpp	Suppresses existing over-threshold complexity in init_handlers().

[achamayou]

@copilot check you did not miss any functions?

[Copilot]

@copilot check you did not miss any functions?

I ran clang-tidy with readability-function-cognitive-complexity (Threshold=50, IgnoreMacros=true) across all 182 CCF source files in the compile database. With the current NOLINTNEXTLINE annotations in place, zero additional warnings were produced. I also confirmed the tool is actually detecting violations — removing the annotation from src/js/registry.cpp immediately surfaced a complexity-of-69 warning for do_execute_request.

So no functions appear to have been missed for the files that could be fully analyzed in this environment. Any files that depend on system headers not present locally (e.g. nghttp2) will be validated by the CI run where all dependencies are available.

[achamayou]

@copilot what's failing in the latest CI then?

[Copilot]

@copilot what's failing in the latest CI then?

CI was failing because setup_basic_hooks in src/node/node_state.h (line 2679) had a cognitive complexity of 66 and was missing a suppression annotation. This function includes the nghttp2 header transitively, which wasn't available in my local sandbox, so it wasn't caught in my earlier analysis. Fixed in the latest commit by adding the missing NOLINTNEXTLINE(readability-function-cognitive-complexity) annotation.