fix(rewards): ChangeSchedule checks net amount instead of total

[g0spel]

Description

Fixes #338 - Broken ChangeSchedule function.

The ChangeSchedule function in the x/rewards module was checking funds availability against the full TotalAmount, ignoring already-released tokens. This prevented governance from updating a schedule after partial release, even when the pool held sufficient funds to cover the remaining balance.

The Bug

// Before (buggy):
if err := k.fundsAvailable(sdkCtx, schedule.TotalAmount); err != nil {

If TotalAmount=1000 and ReleasedAmount=900, the function required 1000 in the pool even though only 100 remained to be paid.

The Fix

// After (fixed):
netAmount := schedule.TotalAmount.Sub(schedule.ReleasedAmount)
if err := k.fundsAvailable(sdkCtx, netAmount); err != nil {

Now only the unreleased portion is checked against the community pool.

Validation

• ReleasedAmount ≤ TotalAmount is already enforced by validateSchedule() on line 91-94
• Denom consistency between TotalAmount and ReleasedAmount is validated on line 83-86
• The Sub() operation is safe because of these pre-conditions

Related

• Issue: [BUG] Broken ChangeSchedule function #338
• E2E test demonstrating the bug: TestRewardsChangeScheduleOverStrictFundsCheckE2E

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 8692b3e9-f0ab-4b77-ac1d-b41337e7dee5

📥 Commits

Reviewing files that changed from the base of the PR and between 3192468 and f3bf3bf.

📒 Files selected for processing (1)

• x/rewards/keeper/msg_server.go

---

Walkthrough

The ChangeSchedule function in the rewards keeper's message server was updated to validate community pool funds against the remaining unreleased amount of a schedule (TotalAmount minus ReleasedAmount) instead of the full TotalAmount. This netAmount is passed to the funds-availability check, and the insufficient-funds error now reflects the remaining amount owed. All other validation logic and event emission remain unchanged.

Estimated code review effort: 1 (Trivial) | ~3 minutes

Sequence Diagram(s)

sequenceDiagram
  participant MsgServer
  participant Schedule
  participant FundsAvailable

  MsgServer->>Schedule: Read TotalAmount, ReleasedAmount
  MsgServer->>MsgServer: Compute netAmount = TotalAmount - ReleasedAmount
  MsgServer->>FundsAvailable: Check funds against netAmount
  FundsAvailable-->>MsgServer: sufficient or insufficient funds result

Loading

Related issues: #338 — Fixes the "Broken ChangeSchedule function" bug by checking fund availability against the remaining unreleased amount instead of the total amount.

Related PRs: None identified.

Suggested labels: bug, rewards

Suggested reviewers: None specified.

🐰 A schedule once demanded its whole,
Ignoring what's already been paid toll,
Now netAmount takes the stage,
Remaining funds, not the full page,
Governance proposals reach their goal!

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly summarizes the main fix: ChangeSchedule now checks the net amount instead of the total.
Description check	✅ Passed	The description matches the change and explains the bug, fix, and validation clearly.
Linked Issues check	✅ Passed	The code change satisfies #338 by checking available funds against the unreleased remainder while preserving existing validations.
Out of Scope Changes check	✅ Passed	The PR appears scoped to the single funds-check fix in msg_server.go with no unrelated changes.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

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

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

[codecov]

Codecov Report

❌ Patch coverage is 0% with 2 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
x/rewards/keeper/msg_server.go	0.00%	2 Missing ⚠️

📢 Thoughts on this report? Let us know!