fix: correct region index mapping in template deploy when unavailable regions are filtered

[canyugs]

Before:

After:

When free tier users deploy using CLI template deploy command and select a region,
they were encountering "REQUIRE_PAID_PLAN" errors even when selecting available regions.

This was caused by an index mismatch bug in pkg/selector/selector.go where:

• regionOptions array contained only available regions (filtered)
• User selected an index from this filtered list
• Code used that index on the original unfiltered regions array

This resulted in selecting the wrong region (potentially an unavailable one).

The fix creates a separate availableRegions array and uses it for indexing,
matching the pattern already applied to internal/cmd/project/create/create.go
in commit 8e5d1ab.

Summary by CodeRabbit

• Bug Fixes
  • Fixed region selection during project creation to ensure only available regions are properly considered, preventing errors from selecting unavailable options.

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[coderabbitai]

Walkthrough

Modifies region selection logic in the selector package to filter regions by availability before using them for project creation, ensuring the selected region index corresponds to an available region.

Changes

Cohort / File(s)	Summary
Region Availability Filtering pkg/selector/selector.go	Introduces availableRegions slice filtered by IsAvailable status; changes project region lookup to use filtered list instead of full regions list to ensure selected index aligns with available regions only

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~8 minutes

Possibly related PRs

• fix: correct region index mapping when unavailable regions are filtered #157: Makes the identical code-level change by filtering regions with IsAvailable and switching the region lookup from regions[index] to availableRegions[index] for project region derivation.

Suggested reviewers

• pan93412

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately describes the main change: fixing a region index mapping bug when unavailable regions are filtered in template deploy.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.

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✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch claude/fix-free-tier-deployment-vGHH5

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[canyugs]

https://linear.app/zeabur/issue/SUP-6852/用cli部署模板，選擇免費區域卻報錯

[Copilot]

Pull request overview

This PR fixes a critical bug where free tier users selecting a region during CLI template deployment would encounter "REQUIRE_PAID_PLAN" errors even when choosing available regions. The issue was caused by an index mismatch between filtered and unfiltered region arrays.

Changes:

• Added availableRegions slice to track only available regions alongside the existing regionOptions string array
• Updated region selection logic to use availableRegions array instead of the original unfiltered regions array when mapping user's selected index

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[coderabbitai]

Actionable comments posted: 0

Caution

Some comments are outside the diff and can’t be posted inline due to platform limitations.

⚠️ Outside diff range comments (1)

pkg/selector/selector.go (1)

105-119: Guard against zero available regions before prompting/indexing.

If all regions are unavailable, availableRegions is empty and the subsequent indexing can panic. Handle the empty case explicitly and return a user-facing error.

🐛 Proposed fix

  availableRegions := make([]model.GenericRegion, 0, len(regions))
  regionOptions := make([]string, 0, len(regions))
  for _, region := range regions {
    if region.IsAvailable() {
      availableRegions = append(availableRegions, region)
      regionOptions = append(regionOptions, region.String())
    }
  }
+ if len(availableRegions) == 0 {
+   return nil, nil, errors.New("no available regions for your plan")
+ }

  projectRegionIndex, err := s.prompter.Select("Select project region", "", regionOptions)
  if err != nil {
    return nil, nil, fmt.Errorf("select project region failed: %w", err)
  }

  projectRegion := availableRegions[projectRegionIndex].GetID()