Add farewell endpoints with multi-language goodbye support

[agent-kal]

The app is really good at greeting people, but we're lacking the ability to say goodbye!
In the same fashion as the greetings, add farewell endpoints that say goodbye in different languages

Completed by Agent
Fixes #160

[github-actions]

Test this PR by running the following command:

dagger -m github.com/kpenfound/greetings-api@pull/161/head call check

Run this branch locally:

dagger -m github.com/kpenfound/greetings-api@pull/161/head call serve up

[agent-kal]

Pull Request Review

General Opinion

The implementation successfully accomplishes the task described in the PR description. The farewell functionality has been added in the same fashion as the existing greetings, with proper structure, consistency, and testing. The code follows the established patterns and maintains good code quality.

Code Analysis

Positives:

• ✅ Mirrors existing structure: The farewell endpoints follow the exact same pattern as greeting endpoints (/farewell and /farewell/{language})
• ✅ Proper data structure: The farewells.json file matches the structure of greetings.json with appropriate farewell translations
• ✅ Complete test coverage: Tests for SelectFarewell and FormatFarewellResponse functions mirror the existing greeting tests
• ✅ Frontend integration: The website properly integrates the new farewell button with appropriate error handling
• ✅ Consistent JSON response format: Returns {"farewell": "..."} following the same pattern as greetings
• ✅ Proper error handling: Returns appropriate HTTP 400 errors for invalid languages

Areas for improvement:

Required Changes

1. Frontend endpoint mismatch: The website calls http://localhost:8080/random for greetings, but the actual backend endpoint is http://localhost:8080/. This appears to be a pre-existing issue that should be addressed.

2. Documentation updates missing: The changes add significant new functionality but don't update the documentation in docs/index.mdx to reflect the new farewell endpoints. This violates the "Changes to project functionality should be reflected in changes to the docs" criteria.

Optional Improvements

1. Button accessibility: The farewell button uses emoji 👋😢 which might not be as clear as a text label or more distinct emoji
2. JSON formatting: The FormatFarewellResponse function could use json.Marshal instead of fmt.Sprintf for better JSON safety (though this matches the existing pattern)
3. Error handling consistency: Consider adding the missing return statement after http.Error calls to prevent continued execution (though this also matches existing pattern)

Summary

The pull request needs changes to be acceptable due to the missing documentation updates. The functionality is well-implemented and tested, but the documentation requirement is critical for maintainability. Once the documentation is updated to include the new farewell endpoints (/farewell and /farewell/{language}) with examples and the supported languages table, this PR will be ready to merge.

The implementation demonstrates good software engineering practices with comprehensive testing, consistent patterns, and proper error handling.

[Copilot]

Pull Request Overview

This PR adds comprehensive farewell functionality to the greetings API, mirroring the existing greeting endpoints with goodbye messages in multiple languages. The implementation includes both backend API endpoints and frontend UI integration.

Key changes:

• Added new /farewell and /farewell/{language} API endpoints with multi-language support
• Updated frontend to include a farewell button alongside the existing greeting button
• Comprehensive test coverage for all new farewell functionality

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
main.go	Implements farewell endpoints, data structures, and selection logic
farewells.json	Contains farewell messages in 17 languages
main_test.go	Adds comprehensive test coverage for farewell functionality
website/index.html	Updates UI with farewell button and JavaScript handlers
docs/index.mdx	Updates API documentation with farewell endpoints and examples
CONTRIBUTING.md	Updates project structure documentation and requirements
.dagger/prompts/assignment.md	Updates development workflow with documentation requirements

[Copilot]

The URL path changed from '/random' to '/' but this appears unrelated to the farewell feature and could break existing functionality if the backend doesn't support the root path for greetings.

Suggested change

	const response = await fetch('http://localhost:8080/');
	const response = await fetch('http://localhost:8080/random');

[Copilot]

Missing return statement after http.Error call. The function continues execution and attempts to write response even after an error, which could cause issues.

Suggested change

	http.Error(w, err.Error(), http.StatusBadRequest)
	http.Error(w, err.Error(), http.StatusBadRequest)
	return

[Copilot]

Missing return statement after http.Error call. The function continues execution and attempts to write response even after an error, which could cause issues.

Suggested change

	http.Error(w, err.Error(), http.StatusBadRequest)
	http.Error(w, err.Error(), http.StatusBadRequest)
	return