The last percentage division without a guard

[denislauri1999]

GenerateStatInfo divides by MaxHp and MaxMp with nothing checking them, while every other place that computes the same two percentages checks first — including one five hundred lines up in the same file:

// PlayerBundleExtensions.cs:238
Hp = player.MaxHp > 0 ? (int)(player.Hp / (float)player.MaxHp * 100) : 100,

// PlayerBundleExtensions.cs:773
HpPercentage = (int)(player.Hp / (float)player.MaxHp * 100),

It never threw and never would. The division is on floats, so a maximum of zero gives NaN rather than an exception, and the cast then puts a meaningless number in the two fields the client draws as the health and mana bars. No log, no symptom to search for.

I swept the rest rather than fixing only what I tripped over

Every other float division of this shape in src/ is guarded:

AliveEntityExtension 102-106	MaxHp > 0 ? … : 100
MonsterBundleExtensions 33	MaxHp > 0 ? … : 100
NpcBundleExtensions 33	MaxHp > 0 ? … : 100
VisualEntityExtension 36	?? 1
PlayerBundleExtensions 238-239	MaxHp > 0 ? … : 100
DamageCalculator.RollBaseDamage	returns early on max <= min
RewardService 98	caller returns on totalDamage <= 0

GenerateStatInfo was the only one left.

The fallback of 100 is the one the guarded computation in the same file already uses, rather than inventing a second convention for the same question.

Removing the guard fails one of the three tests.

Summary by CodeRabbit

• Bug Fixes

  • Prevented health and mana displays from showing invalid values when their maximum is zero.
  • Zero-maximum stats now display as 100% instead of causing an invalid calculation.
  • Preserved the existing percentage calculations for stats with valid maximum values.

• Tests

  • Added coverage for normal percentages, zero-maximum handling, and consistency with guarded calculations.

[coderabbitai]

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📥 Commits

Reviewing files that changed from the base of the PR and between 55dc38c and 4a67e5f.

📒 Files selected for processing (2)

• src/NosCore.GameObject/Ecs/Extensions/PlayerBundleExtensions.cs
• test/NosCore.GameObject.Tests/Ecs/Extensions/StatInfoPercentageTests.cs

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Walkthrough

GenerateStatInfo now avoids invalid percentage calculations when maximum health or mana is zero. New tests cover normal percentages, zero-maximum behavior, and consistency with the guarded health formula.

Changes

Stat percentage handling

Layer / File(s)	Summary
Guard stat percentages and validate calculations src/NosCore.GameObject/Ecs/Extensions/PlayerBundleExtensions.cs, test/NosCore.GameObject.Tests/Ecs/Extensions/StatInfoPercentageTests.cs	GenerateStatInfo returns 100 when maximum health or mana is zero. Tests cover ordinary percentages, zero-maximum values, and the guarded health calculation.

Estimated code review effort: 2 (Simple) | ~10 minutes

Merge Risk: ⚪ Minimal · up to 4a67e

The change guards health and mana percentage calculations against zero maximum values and uses the existing 100% fallback convention, with focused tests covering the behavior. No actionable merge-blocking risk remains beyond normal checks and review.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly identifies the main change: adding a guard to the final unguarded percentage division.
Docstring Coverage	✅ Passed	Docstring check was indeterminate for this PR — some files could not be analyzed in time. Not blocking.
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.

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🧪 Generate unit tests (beta)

• Create PR with unit tests

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