Update README.md

Author: bact

tests/README.md

@@ -1,39 +1,61 @@
-# Test cases
+# Test suites and execution
 
-The default test suite, triggered by the `unittest tests` command, encompasses
-all test cases within the `tests.core` and `tests.compact` packages.
-This suite is defined within the `__init__.py` file in this directory.
+The default test suite is executed using the `unittest tests` command.
+It includes all test cases within the `tests.core` and `tests.compact`
+packages, as defined in the `tests/__init__.py` file.
 
-Tests are categorized into three groups: core, compact, and extra.
+To optimize CI/CD resource utilization and manage dependency overhead,
+tests are categorized into four tiers based on their resource
+requirements and complexity: "core", "compact", "extra", and "noauto".
 
+The following table outlines the automated test coverage across
+supported Python versions and operating systems:
+
+| Python         | Ubuntu  | Windows | macOS |
+| -------------- | ------- | ------- | ----- |
+| 3.14 (Latest)  | O+C     | O       | O     |
+| 3.13           | O+C+X   | O+C     | O+C   |
+| 3.12           | O       |         |       |
+| 3.11           | O       |         |       |
+| 3.10           | O       |         |       |
+| 3.9 (Earliest) | O+C     | O+C     | O+C   |
+        
 ## Core tests (test_*.py)
 
 - Run `unittest tests.core`
 - Focus on core functionalities.
 - Do not rely on external dependencies beyond the standard library.
-- Test with all officially supported Python versions
-  (currently 3.9, 3.10, 3.11, 3.12, 3.13, and 3.14).
+- Tested on all supported operating systems and all active Python versions.
+- Test case class suffix: `TestCase`
 
 ## Compact tests (testc_*.py)
 
 - Run `unittest tests.compact`
-- Test a limited set of functionalities that rely on a stable and small subset
-  of optional dependencies specified in `pyproject.toml`.
+  - Need dependencies from `pip install "pythainlp[compact]"`
+- Test a limited set of functionalities that rely on a stable
+  and small set of dependencies.
 - These dependencies are `PyYAML`, `nlpo3`, `numpy`, `pyicu`,
   `python-crfsuite`, and `requests`.
-- Test with the latest two stable Python versions.
+- Tested on:
+  - All OSes: earliest and second-latest supported Python versions
+  - Ubuntu: additionally tested on the latest version
+- Test case class suffix: `TestCaseC`
 
 ## Extra tests (testx_*.py)
 
 - Run `unittest tests.extra`
-- Explore functionalities that rely on optional dependencies specified in the
-  `project.optional-dependencies` section of `pyproject.toml`.
+  - Need dependencies from `pip install "pythainlp[compact,extra]"`
+- Test more functionalities that rely on larger set of dependencies
+  or one that require more time or computation.
+- Only tested on Ubuntu using the second-latest Python version.
+- Test case class suffix: `TestCaseX`
 
 ## Noauto tests (testn_*.py)
 
 - These dependencies might include huge libraries like `tensorflow`.
 - Due to dependency complexities, these functionalities may not be tested
   in the CI/CD pipeline.
+- Test case class suffix: `TestCaseN`
 
 ## Robustness tests (test_robustness.py)