feat(config): support forwardPorts range syntax expansion

[skevetter]

Summary

Adds support for port range notation (e.g. 3000-3005) in the devcontainer forwardPorts field, expanding ranges into individual ports during config merging. This enables users to specify ["8080", "3000-3005"] and have all 7 ports forwarded. Invalid ranges (start > end, negative, non-numeric) are rejected gracefully. Includes 14 unit tests covering single ports, ranges, mixed inputs, deduplication across ranges, and error cases, plus an E2E test validating range expansion through read-configuration --include-merged-configuration.

Summary by CodeRabbit

• New Features

  • Forward ports configuration now supports range syntax notation (e.g., 3000-3005), which automatically expands into individual ports during configuration processing.

• Tests

  • Added comprehensive end-to-end and unit tests validating port range expansion, deduplication behavior, and configuration merging with mixed port formats.

[netlify]

✅ Deploy Preview for devsydev canceled.

Name	Link
🔨 Latest commit	a064e12
🔍 Latest deploy log	https://app.netlify.com/projects/devsydev/deploys/69f6d32530e2fe00086e812e

[coderabbitai]

Caution

Review failed

Pull request was closed or merged during review

📝 Walkthrough

Walkthrough

This PR adds port range expansion support to devcontainer configuration merging. Port ranges in forwardPorts (e.g., 3000-3005) are now parsed and expanded into individual port entries during configuration merge, with comprehensive unit and e2e test coverage.

Changes

Port Range Expansion for Forward Ports

Layer / File(s)	Summary
Port Range Parsing & Expansion pkg/devcontainer/config/merge.go	New parsePortRange validates start-end syntax with error checking for non-negative integers and start <= end. expandPortRange expands ranges into individual port strings; entries containing : are passed through unchanged.
Merge Integration pkg/devcontainer/config/merge.go	mergeForwardPorts updated to call expandPortRange on each entry, skip invalid ranges, and continue using localhost-prefixed deduplication before appending expanded ports to the result.
Unit Tests pkg/devcontainer/config/merge_test.go	Tests cover range expansion (3000-3002 → ["3000", "3001", "3002"]), single ports and host:port passthrough, mixed inputs, deduplication across overlapping ranges, and skipping of invalid ranges while preserving valid ports.
E2E Test Data e2e/tests/readconfiguration/testdata-port-range/.devcontainer/devcontainer.json	Devcontainer configuration with forwardPorts set to [8080, "3000-3005"].
E2E Test & Suite Registration e2e/tests/readconfiguration/readconfiguration.go, e2e/e2e_suite_test.go	E2E test runs read-configuration --include-merged-configuration against the port-range test data and validates that mergedConfiguration.forwardPorts contains the expanded individual ports (8080, 3000, 3001, ..., 3005) with exactly 7 entries. Test suite registers the readconfiguration package via blank import.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~22 minutes

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and specifically describes the main change: adding support for port range syntax expansion in forwardPorts configuration.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Review rate limit: 0/1 reviews remaining, refill in 60 minutes.}

_{Comment @coderabbitai help to get the list of available commands and usage tips.}