fix(token-2022/metadata/anchor): revive program excluded from CI due to stale spl-token-metadata-interface version

[NikkiAung]

Summary

tokens/token-2022/metadata/anchor has been excluded from CI with the comment "build failed - program outdated" since anchor-spl was upgraded to 1.x. This PR fixes the root cause and re-enables the program in CI.

Root cause

The program directly pinned two SPL interface crates at 2023-era versions:

spl-token-metadata-interface = "0.3.3"   # stale
spl-type-length-value        = "0.4.3"   # stale

while anchor-spl = "1.0.2" (resolves to 1.1.2) already transitively pulls spl-token-metadata-interface 0.8.0 and spl-type-length-value 0.9.1. Cargo ended up with two incompatible versions of both crates in the dependency tree. The older chain brought in a stale solana-program that conflicted with the solana-zk-token-sdk compile unit, causing the build to fail with unresolved symbol errors.

Fix

Align the direct pins to the versions anchor-spl already resolves:

- spl-token-metadata-interface = "0.3.3"
+ spl-token-metadata-interface = "0.8.0"
- spl-type-length-value = "0.4.3"
+ spl-type-length-value = "0.9.1"

Three minor call-site API fixes to match the newer crate versions:

• initialize.rs: replace removed DEFAULT_LAMPORTS_PER_BYTE_YEAR / DEFAULT_EXEMPTION_THRESHOLD rent constants with Rent::get()?.minimum_balance() (already the pattern used by update_field.rs in the same program)
• update_field.rs, update_authority.rs: rename struct field token_program_id → program_id in TokenMetadataUpdateField / TokenMetadataUpdateAuthority (field was renamed in anchor-spl 1.1.x)

No account structures, instruction logic, or TypeScript test code required changes.

Verification

• cargo tree -i spl-token-metadata-interface now shows a single v0.8.0 (no more v0.3.4)
• anchor build succeeds locally
• All 7 existing tests pass locally

Test plan

• CI anchor.yml matrix picks up tokens/token-2022/metadata/anchor (no longer in .ghaignore) and goes green
• anchor build succeeds
• All 7 tests in tests/metadata.ts pass (initialize mint w/ metadata, update field, update with custom field, remove custom field, change update authority, emit metadata × 2)

🤖 Generated with Claude Code

[greptile-apps]

Greptile Summary

The PR restores the Token-2022 metadata Anchor example to CI by aligning SPL interface dependencies, adapting renamed CPI account fields, and correcting incremental metadata rent funding.

Confidence Score: 5/5

The PR appears safe to merge.

No blocking failures remain in the reviewed fix.

Important Files Changed

Filename	Overview
.github/.ghaignore	Re-enables CI discovery for the repaired Anchor example.
tokens/token-2022/metadata/anchor/programs/metadata/Cargo.toml	Aligns direct SPL interface dependencies with the versions used by anchor-spl.
tokens/token-2022/metadata/anchor/programs/metadata/src/instructions/initialize.rs	Funds only the incremental rent required for the metadata TLV bytes using the runtime rent sysvar, completing the prior rent-overhead fix.
tokens/token-2022/metadata/anchor/programs/metadata/src/instructions/update_authority.rs	Adapts the update-authority CPI accounts to the renamed program_id field.
tokens/token-2022/metadata/anchor/programs/metadata/src/instructions/update_field.rs	Adapts the update-field CPI accounts to the renamed program_id field.
tokens/token-2022/metadata/anchor/package.json	Adds explicit Node typings and updates TypeScript tooling for the re-enabled project.
tokens/token-2022/metadata/anchor/pnpm-lock.yaml	Locks the updated TypeScript and Node type dependencies used by CI.
tokens/token-2022/metadata/anchor/tsconfig.json	Updates the TypeScript target, libraries, and type environment for current tooling.

_{Reviews (4): Last reviewed commit: "fix(#642): pin @types/node to ^22.x and ..." | Re-trigger Greptile}

[greptile-apps]

Double-charged rent overhead

When initialization runs, Anchor has already rent-funded the mint, but minimum_balance(data_len) includes the fixed account-storage overhead again even though data_len contains only the added metadata TLV bytes, causing every payer to lock excess lamports in the mint.

Knowledge Base Used: Tokens Directory Overview

[NikkiAung]

Good catch by @greptile-apps — addressed in 2b81753.

minimum_balance(data_len) prices (128 + data_len) bytes, but the mint's base 128-byte account overhead is already funded by Anchor's init constraint. That caused the payer to lock ~890,880 extra lamports (≈0.0009 SOL) per mint.

Fixed by computing only the incremental rent for the extension bytes:

let rent = Rent::get()?;
let lamports = rent.minimum_balance(data_len).saturating_sub(rent.minimum_balance(0));

All 7 tests still pass locally.

[greptile-apps]

The fix is correct. minimum_balance(data_len) - minimum_balance(0) is the standard pattern for computing incremental rent on Token-2022 extensions — it isolates the cost of the variable-length metadata bytes without re-pricing the 128-byte base account that Anchor's init already covers.

One small thing worth verifying: saturating_sub silently clamps to zero if minimum_balance(data_len) < minimum_balance(0), which can't happen in practice since minimum_balance is monotonically increasing, but it's the right defensive choice here. The pattern is correct.

LGTM on the fix.