[Testing] Zero test coverage for `SendTokensScreen` — payment signing and Lobstr delegation

[cybermax4200]

Why this matters now: SendTokensScreen.tsx handles the entire payment flow: input validation, destination address validation, amount validation, asset selection (XLM/ECO), Lobstr delegation vs in-app signing, and transaction submission. A bug here could send tokens to wrong addresses, submit invalid transactions, or silently fail.

Problem / What: src/screens/SendTokensScreen.tsx (291 lines) — no test file. The screen has complex branching: Lobstr wallet (line 65-85) vs in-app wallet (line 87-101), with different code paths for each.

Key Challenges:

• Mock useWalletStore, useStellarWallet, getInAppSecret.
• Mock signAndSubmitPayment, isValidAmount, isValidPublicKey.
• Mock openLobstrForPayment, LobstrNotInstalledError.
• Mock Alert.alert.
• Test: invalid destination address → error displayed.
• Test: invalid amount → error displayed.
• Test: Lobstr wallet → opens Lobstr, shows confirmation alert.
• Test: in-app wallet → signs and submits, shows success alert.
• Test: Lobstr not installed → error displayed.
• Test: network failure → error displayed.
• Test: input validation for destination and amount.

Acceptance Criteria:

• Test file src/__tests__/SendTokensScreen.test.tsx with 10+ test cases.
• Input validation for destination and amount.
• Lobstr vs in-app signing paths.
• Error handling for network failures and missing keys.
• Success confirmation display.
• All tests pass with npm test.

Relevant files/functions:

• src/screens/SendTokensScreen.tsx (entire file)
• src/__tests__/SendTokensScreen.test.tsx (new)

Out of scope: Real Stellar transaction submission.

Labels: testing, advanced, wallet, screens

[Codex723]

Payment flows are exactly where strong test coverage matters most, and this screen has several critical paths that need to be verified. I can take this on confidently, covering validation, Lobstr delegation, in-app signing, missing keys, network failures, and successful submissions with 10+ focused tests and a clean npm test result.

[grantfox-oss]

🦊 GrantFox — @Codex723 has been assigned to this issue as part of the Third Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #82)
2. Your PR will be reviewed by the ecotask-network maintainers

Good luck! Track your progress on GrantFox.

[Codex723]

Hello @cybermax4200 pls kindly review my pr