Task 1.4: Wildcard Routes and Token Management

Summary

Implement wildcard routing for the confirm endpoint to support magic link authentication and email confirmation tokens.

Motivation

Following Let’s Go Chapter 2.4, we need to implement the core authentication mechanism for buylater.email: token-based magic links sent via email. This allows users to confirm their email submissions and eventually manage their subscriptions without passwords through secure, unique URLs.

Acceptance Criteria

Route pattern GET /confirm/{token} accepts token parameter
Token extraction using r.PathValue("token") works correctly
Basic token validation (length, format) implemented
Invalid tokens return 404 with helpful error message
Valid tokens show email confirmation success placeholder
Tokens must be at least 32 characters alphanumeric

Technical Requirements

Implementation Details

Use wildcard route pattern /confirm/{token} for magic link confirmation
Extract token with r.PathValue("token")
Validate token format: alphanumeric, minimum 32 characters
Return structured error responses for invalid tokens
Create placeholder email confirmation success interface for valid tokens
Replace existing /confirm route with wildcard version - all confirmations require tokens

Dependencies

Task 1.3 completed (multiple route implementation)

Testing Strategy

Unit Tests

Token validation function works correctly
Valid tokens return success response
Invalid tokens return appropriate errors

Integration Tests

Wildcard route correctly extracts token values

Manual Testing

Valid token URLs (32+ chars) show email confirmation success
Invalid token URLs return 404
Empty or malformed tokens handled gracefully
URL patterns like /confirm/abc123... work correctly

Definition of Done

All acceptance criteria met
All specified tests pass
Code follows project conventions (go fmt, go vet)
No new console errors or warnings
Relevant documentation updated
Human verification completed successfully
Git commit created with proper message format

Implementation Notes

Approach

Implement the magic link token system that will be core to buylater.email’s password-free email confirmation and authentication. Focus on validation and error handling.

Key Files to Modify

main.go - Add wildcard confirm route handler and token validation function

Potential Risks

Token validation too strict or too loose
Security issues with token format
Route conflicts with existing patterns

Success Metrics

Users can confirm their email submissions through secure magic link URLs, with clear error messages for invalid tokens.

Blocks: Task 1.5 (method-based routing for form processing)
Blocked by: Task 1.3 (needs basic routing structure)
Related: Future magic link email sending and token generation tasks

Implementation Log

2025-07-20 - Implementation Complete

Replaced /confirm route with wildcard /confirm/{token} route for magic links
Added confirmWithToken handler that extracts and validates tokens using r.PathValue("token")
Implemented isValidToken function with alphanumeric validation and 32+ character requirement
Invalid tokens return 404 automatically through http.NotFound()
Valid tokens show email confirmation success message
Added regexp import for token format validation
Verified code formatting with go fmt and go vet
Build successful with go build

Final Verification

Human Tester: [Name]
Date Completed: [YYYY-MM-DD]
Verification Result: [Pass/Fail]
Notes: [Any issues found or additional observations]

task_id: “1.4” title: “Wildcard Routes and Token Management” status: “pending” priority: “high” estimated_effort: “medium” created: “2025-07-20” assigned_to: “pair” related_rfds: “RFD 003”