fix: format custom token balances with token decimals

[Emilvooo]

Summary

formatTokenBalance used formatEther (hardcoded 18 decimals) to scale raw on-chain balances. Custom tokens with non-18 decimals displayed incorrect amounts in the asset list (e.g. a 9-decimal token with 979 tokens showed as 0).

Changes

• Replace formatEther(balance) with formatUnits(balance, decimals) in formatTokenBalance, defaulting to 18
• Pass Number(token.decimals) from useGetCustomTokenBalances when formatting custom token balances

Backward compatibility

• decimals parameter defaults to 18, so all existing callers (B3TR, VOT3, veDelegate, SASS) are unaffected
• Only custom tokens with non-18 decimals see a behavioral change (from broken to correct)

Summary by CodeRabbit

• Bug Fixes
  • Token balances now display correctly using each token's actual decimal precision, fixing incorrect balance rounding.
• New Features
  • Improved handling for tokens with custom decimal settings so values are scaled and presented more accurately.
• Chores
  • Added stricter address validation to reduce failed or unnecessary balance lookups.

[github-actions]

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ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: af675242-eb97-43f7-b60b-f5781d107549

📥 Commits

Reviewing files that changed from the base of the PR and between 591cb9d and b8a7ff8.

📒 Files selected for processing (1)

• packages/vechain-kit/src/hooks/api/wallet/useGetCustomTokenBalances.ts

📝 Walkthrough

Walkthrough

Updated token balance formatting to support arbitrary token decimals: formatTokenBalance now accepts an optional decimals parameter and uses formatUnits; the custom token balance hook passes token decimals and adds address validation checks.

Changes

Cohort / File(s)	Summary
Token Balance Formatting packages/vechain-kit/src/utils/formattingUtils.tsx	Replaced formatEther with formatUnits; formatTokenBalance(balance: bigint, decimals: number = 18) added decimals param; return now includes scaled and formatted in addition to original.
Custom Token Balance Hook packages/vechain-kit/src/hooks/api/wallet/useGetCustomTokenBalances.ts	Query key/signature extended to include decimals; hook passes Number(token.decimals) to formatTokenBalance; added isValidAddress checks to enabled condition; minor import reformatting.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Suggested labels

safe-to-build

Suggested reviewers

• Agilulfo1820

Poem

🐰 I nibbled decimals, small and neat,
I swapped formatEther for units sweet,
Now balances scale and show their face,
Precision hops into the place. ✨

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately summarizes the main change: fixing custom token balance formatting to correctly handle token decimals instead of hardcoding 18 decimals.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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• Post copyable unit tests in a comment

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[coderabbitai]

Actionable comments posted: 3

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@packages/vechain-kit/src/hooks/api/wallet/useGetCustomTokenBalances.ts`:
- Around line 40-43: The query cache key for useGetCustomTokenBalances must
include token.decimals because formatTokenBalance(tokenBalanceOriginal[0],
Number(token.decimals)) depends on it; update the key that currently uses
token.address and address to also include token.decimals so React Query will
refetch/segregate cached results when decimals change (locate the
useQuery/useGetCustomTokenBalances call and adjust its key tuple to include
token.decimals alongside token.address and address).
- Around line 26-35: In useGetCustomTokenBalances, validate addresses with
isValidAddress() before calling getErc20Balance and stop queries from running on
invalid inputs by adding an enabled flag to each query entry (pattern used in
useIpfsMetadatas); update the queryKey returned by getCustomTokenBalanceQueryKey
to include token.decimals because formatTokenBalance/scaled depends on it;
specifically ensure each mapped query uses enabled: !!address &&
isValidAddress(address) && !!token.address && isValidAddress(token.address) &&
!!network.nodeUrl and that the queryFn still calls
getErc20Balance(token.address, address, { networkUrl: network.nodeUrl }) and
then formats with formatTokenBalance(balance, token.decimals).

In `@packages/vechain-kit/src/utils/formattingUtils.tsx`:
- Around line 95-96: formatTokenBalance currently forwards a potentially
NaN/invalid decimals value to formatUnits causing runtime errors; inside
formatTokenBalance normalize and validate the decimals parameter (e.g., coerce
to a finite number via Number(...) or Number.isFinite check, default to 18 when
invalid, and Math.trunc/clamp to a non-negative integer) before calling
formatUnits so only a safe integer decimals is passed to formatUnits.

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 4a39adea-d665-4bf6-abac-14c316a47d1a

📥 Commits

Reviewing files that changed from the base of the PR and between 40d9973 and e980f3f.

📒 Files selected for processing (2)

• packages/vechain-kit/src/hooks/api/wallet/useGetCustomTokenBalances.ts
• packages/vechain-kit/src/utils/formattingUtils.tsx

[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@packages/vechain-kit/src/hooks/api/wallet/useGetCustomTokenBalances.ts`:
- Around line 13-17: getCustomTokenBalanceQueryKey currently uses decimals as-is
which can become NaN when token.decimals is undefined, causing unstable cache
keys; update the function (and the similar key helper around lines 25-29) to
normalize decimals to a stable value (e.g., use a fallback like 0 or null and/or
coerce with Number(decimals ?? 0)) so the returned array always contains a
consistent primitive and avoids NaN-based inequality (refer to
getCustomTokenBalanceQueryKey to locate and change the key composition).

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: ec78bd6a-f0f9-4d46-9aaa-e286943ea63a

📥 Commits

Reviewing files that changed from the base of the PR and between e980f3f and 591cb9d.

📒 Files selected for processing (2)

• packages/vechain-kit/src/hooks/api/wallet/useGetCustomTokenBalances.ts
• packages/vechain-kit/src/utils/formattingUtils.tsx

🚧 Files skipped from review as they are similar to previous changes (1)

• packages/vechain-kit/src/utils/formattingUtils.tsx