feat(walletkit): multi-chain balances with zero-balance natives and redesigned rows

[ignaciosantise]

Description

Reworks the sample wallet Balances page. It now fetches balances across all supported namespaces (eip155, solana, sui, ton, tron) — returning every EVM chain in a single call when chainId is omitted — filters out spam/airdrop tokens, always shows mainnet native tokens even at a 0 balance (so their address is visible), and adds per-token filter chips. Each row is redesigned to the TokenBalanceCard spec: token icon with chain badge on the left, compact amount (no inline USD value), a 6...6 truncated per-chain address, and a tap-to-copy card with a new CopySimple.svg copy icon and a confirmation toast. The single "Wallet address" header was removed since multiple chains/addresses are now supported.

Resolves # (issue)

How Has This Been Tested?

flutter analyze passes clean on the changed files. Verified manually by opening the Balances tab in the WalletKit example app: rows render icon-left with chain badges, amounts/addresses format correctly, and tapping a card copies its address and shows the toast.

Due Dilligence

• Breaking change
• Requires a documentation update

[claude]

Claude finished @ignaciosantise's task in 2m 5s —— View job

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Code Review

• Gather context
• Read changed files
• Analyze code
• Post findings

Found 4 issue(s)

Issue 1: Type cast crash when API returns integer value

ID: blockchain-api-double-cast-f2c1
File: packages/reown_walletkit/example/lib/utils/blockchain_api_utils.dart:46
Severity: HIGH
Category: code_quality

Context:

• Pattern: b['value'] as double? and a['value'] as double? in the sort comparator
• Risk: In Dart, int cannot be cast to double — if the JSON response returns "value": 0 (integer literal), this throws TypeError: type 'int' is not a subtype of type 'double?' at runtime
• Impact: The entire balance fetch crashes for any account where a token has an integer value field; since 0 is a common API value, this will fire on any account with zero-value tokens
• Trigger: Any API response where value is a JSON integer rather than a float (very common for zero balances)

Recommendation: Use num? then .toDouble(), matching the pattern already used correctly in _processBalances:

final bValue = (b['value'] as num?)?.toDouble() ?? 0.0;
final aValue = (a['value'] as num?)?.toDouble() ?? 0.0;

Fix this →

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Issue 2: Unsafe null map access on balance['quantity'] in build

ID: balances-page-quantity-null-access-a3d7
File: packages/reown_walletkit/example/lib/pages/balances_page.dart:383
Severity: MEDIUM
Category: code_quality

Context:

• Pattern: double.tryParse(balance['quantity']['numeric']) — no null-safe access on balance['quantity']
• Risk: If the API ever returns a balance entry without a quantity key (or with null), the inner ['numeric'] access throws Null check operator used on a null value. _processBalances does inject placeholder entries with a quantity, but raw API entries are not guaranteed to have it.
• Impact: Throws Null exception during build, causing the widget tree to show a red error screen
• Trigger: Any token returned from the API where the quantity field is absent or null

Recommendation: Use null-safe access matching the style already used in _processBalances line 275:

final quantity = double.tryParse(
  balance['quantity']?['numeric']?.toString() ?? '',
) ?? 0.0;

Fix this →

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Issue 3: Empty state still gates on EVM-only check

ID: balances-page-evm-only-empty-state-b1e4
File: packages/reown_walletkit/example/lib/pages/balances_page.dart:317
Severity: LOW
Category: code_quality

Context:

• Pattern: final chainKeys = _keysService.getKeysForChain('eip155'); ... chainKeys.isEmpty ? Center(child: Text('No EVM accounts found')) in build
• Risk: A wallet with only Solana/Tron/TON keys (no EVM) will show "No EVM accounts found" and render nothing, even though multi-chain balances are now supported and those accounts have been fetched
• Impact: Misleading UX; non-EVM-only wallets see a dead page

Recommendation:

// Replace lines 317-327 in build():
final hasAnyAccount = _addresses.isNotEmpty;
// ...
body: !hasAnyAccount
    ? Center(child: Text('No accounts found', ...))
    : RefreshIndicator(...)

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Issue 4: _addresses getter calls _addressFor twice per namespace

ID: balances-page-double-keylookup-c9f2
File: packages/reown_walletkit/example/lib/pages/balances_page.dart:54
Severity: LOW
Category: performance

Context:

• Pattern: if (_addressFor(ns) != null) ns: _addressFor(ns)! — each namespace does two getKeysForChain calls
• Risk: Minor inefficiency; if getKeysForChain ever has side effects or cost (e.g., DB read), this doubles the work. Also fragile: a TOCTOU if the keystore changes between the two calls.

Recommendation:

Map<String, String> get _addresses => {
  for (final ns in _supportedNamespaces)
    if (_addressFor(ns) case final addr?) ns: addr,
};

Or store to a local variable: final addr = _addressFor(ns); if (addr != null) ns: addr.

[Copilot]

Pull request overview

This PR reworks the WalletKit example app’s Balances screen to support multi-namespace balance fetching and a redesigned, copy-to-clipboard row UI aligned with the TokenBalanceCard spec.

Changes:

• Updated balance fetching to support optional chainId (enabling a single-call “all EVM chains” query when omitted) and to aggregate results across supported namespaces.
• Added balance post-processing to filter spam/airdrop tokens and ensure mainnet native tokens are shown even at 0 balance.
• Redesigned balance rows (chain badge, compact amount formatting, truncated per-chain address, tap-to-copy with new CopySimple.svg icon and toast).

Reviewed changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 2 comments.

File	Description
packages/reown_walletkit/example/lib/utils/blockchain_api_utils.dart	Makes chainId optional and omits the query param when absent to support multi-chain EVM balance fetches.
packages/reown_walletkit/example/lib/pages/balances_page.dart	Implements multi-namespace fetching, spam filtering, native-token inclusion at 0 balance, and redesigned tappable balance rows with copy + toast.
packages/reown_walletkit/example/ios/Runner.xcodeproj/project.pbxproj	Changes Xcode project objectVersion (appears incidental).
packages/reown_walletkit/example/assets/CopySimple.svg	Adds a new SVG asset used for the copy icon in balance rows.

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[ignaciosantise]

All 4 findings addressed in 1af443f:

Issue	Action
1 — Type cast crash on integer value (blockchain_api_utils.dart)	Fixed. Sort comparator now uses (… as num?)?.toDouble() ?? 0.0, so an integer 0 from the API no longer throws a TypeError. Matches the safe pattern in _processBalances.
2 — Unsafe balance['quantity']['numeric'] access	Fixed. Now double.tryParse(balance['quantity']?['numeric']?.toString() ?? '') ?? 0.0 — null-safe and string-coerced.
3 — Empty state gates on EVM-only check	Fixed. Generalized to _addresses.isNotEmpty with the message "No accounts found", so non-EVM wallets are no longer shown a dead "No EVM accounts found" page.
4 — _addresses calls _addressFor twice per namespace	Fixed. Resolves each namespace once via if (_addressFor(ns) case final address?) ns: address, removing the double lookup and TOCTOU window.

flutter analyze is clean on both files.