Add Vitest unit tests for JS parsing, formatting, and utility logic

[Copilot]

The TypeScript modules (utils.ts, pr-comment-formatter.ts, and the file-parsing logic in main.ts) had no automated unit tests.

Changes

• Extract parsing logic — Moved the results-file parser out of main.ts into src/parse-results.ts (parseResultsFile(content: string): Map<string, CheckResult[]>) so it can be tested in isolation. main.ts now delegates to this function.

• Test suite (27 tests across 3 files):

  • src/utils.test.ts — decodeHtmlEntities: named, decimal, hex, unknown entities
  • src/parse-results.test.ts — parseResultsFile: empty input, no FILE: lines, errors, warnings, empty result arrays
  • src/pr-comment-formatter.test.ts — PRCommentFormatter: summary counts, success/error/warning comment output, HTML entity decoding in rendered output

• Test fixtures — tests/fixtures/results-with-errors.txt, results-with-warnings.txt, results-empty.txt representing real plugin-check output format.

• Vitest setup — Added vitest dev dependency, vitest.config.ts, and "test": "vitest run" script. Excluded the config from tsc compilation and ESLint.

• CI — New unit-tests job in test.yml runs npm test on every PR/push ahead of the integration test job.

[github-actions]

🔍 WordPress Plugin Check Report

❌ Status: Failed

📊 Report

🎯 Total Issues	❌ Errors	⚠️ Warnings
9	8	1

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❌ Errors (8)

📁 hello.php (7 errors)

📍 Line	🔖 Check	💬 Message
0	plugin_header_no_license	Missing "License" in Plugin Header. Please update your Plugin Header with a valid GPLv2 (or later) compatible license.
0	missing_direct_file_access_protection	PHP file should prevent direct access. Add a check like: if ( ! defined( 'ABSPATH' ) ) exit;
49	WordPress.WP.AlternativeFunctions.rand_mt_rand	mt_rand() is discouraged. Use the far less predictable wp_rand() instead.
62	WordPress.Security.EscapeOutput.OutputNotEscaped	All output should be run through an escaping function (see the Security sections in the WordPress Developer Handbooks), found '__'.
62	WordPress.WP.I18n.TextDomainMismatch	Mismatched text domain. Expected 'hello-dolly-copy' but got 'hello-dolly'.
63	WordPress.Security.EscapeOutput.OutputNotEscaped	All output should be run through an escaping function (see the Security sections in the WordPress Developer Handbooks), found '$lang'.
64	WordPress.Security.EscapeOutput.OutputNotEscaped	All output should be run through an escaping function (see the Security sections in the WordPress Developer Handbooks), found '$chosen'.

📁 readme.txt (1 error)

📍 Line	🔖 Check	💬 Message
0	no_plugin_readme	The plugin readme.txt does not exist.

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⚠️ Warnings (1)

📁 hello.php (1 warning)

📍 Line	🔖 Check	💬 Message
72	WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedFunctionFound	Functions declared in the global namespace by a theme/plugin should start with the theme/plugin prefix. Found: "dolly_css".

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🤖 Generated by WordPress Plugin Check Action • Learn more about Plugin Check

[Copilot]

Pull request overview

Adds a Vitest unit test suite around the action’s TypeScript utility/formatting/parsing logic by extracting the results parsing into a standalone module and wiring unit tests + CI to run them.

Changes:

• Extracts plugin-check results parsing from main.ts into src/parse-results.ts.
• Introduces Vitest configuration and 3 new unit test files plus fixtures for results parsing.
• Adds a new GitHub Actions workflow job to run npm test in CI.

Reviewed changes

Copilot reviewed 12 out of 14 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
vitest.config.ts	Adds Vitest config to run src/**/*.test.ts tests.
tsconfig.json	Excludes test files and Vitest config from TypeScript compilation.
package.json	Adds vitest and npm test script.
eslint.config.mjs	Ignores vitest.config.ts in ESLint.
.github/workflows/test.yml	Adds unit-tests job to execute unit tests in CI.
src/parse-results.ts	New standalone results-file parser used by main.ts.
src/main.ts	Delegates results parsing to parseResultsFile.
src/utils.test.ts	Adds unit tests for HTML entity decoding.
src/parse-results.test.ts	Adds unit tests for parsing the results file using fixtures.
src/pr-comment-formatter.test.ts	Adds unit tests for PR comment formatting output.
tests/fixtures/results-with-errors.txt	Fixture representing plugin-check output with errors/warnings.
tests/fixtures/results-with-warnings.txt	Fixture representing plugin-check output with warnings.
tests/fixtures/results-empty.txt	Fixture representing plugin-check output with no issues.

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