feat : add test functions & split PR

- add test function for plot
- split ratioplot to the other PR
- change hint highlight to red rectangle

Author: Ming-Yan

.pre-commit-config.yaml

@@ -3,7 +3,7 @@ ci:
 
 repos:
 - repo: https://github.com/pre-commit/pre-commit-hooks
-  rev: v4.3.0
+  rev: v4.0.1
   hooks:
   - id: check-added-large-files
   - id: check-case-conflict
@@ -23,7 +23,7 @@ repos:
     args: ["--include-version-classifiers", "--max-py-version=3.11"]
 
 - repo: https://github.com/PyCQA/isort
-  rev: 5.10.1
+  rev: 5.12.0
   hooks:
   - id: isort
     args: ["-a", "from __future__ import annotations"]