Add `get_version` SDK method

[Levi-Ojukwu]

Description:

The invoice_liquidity contract exposes a get_version() view function (at lib.rs:205-207) that returns the contract version string (currently "1.0.0" from constants.rs). However, the SDK does not expose this method, making it impossible for frontend applications to display or check the deployed contract version.

The contract implementation is straightforward:

pub fn get_version(env: Env) -> soroban_sdk::String {
    soroban_sdk::String::from_str(&env, crate::constants::CONTRACT_VERSION)
}

The SDK method should:

1. Call the contract's get_version view function
2. Return the version string
3. Handle the case where the contract is not deployed (return null or throw)

Why it matters: Version checking is essential for frontend compatibility. When the contract is upgraded, frontends need to verify they're interacting with the expected version.

Acceptance Criteria:

• Create sdk/src/methods/version.ts with a getVersion(client: ILNClient) function
• Return type should be Promise<string>
• Add unit tests in sdk/src/methods/version.test.ts using mock client
• Export from sdk/src/index.ts
• Add JSDoc documentation

Relevant Files: contracts/invoice_liquidity/src/lib.rs:205-207, contracts/invoice_liquidity/src/constants.rs:5, sdk/src/index.ts

---

[Okorie2000-code]

Hi Maintainer,

I'd like to work on this issue. I have experience with SDK development and can submit a clean PR within 48 hours.

[Akanimoh12]

Hi, I'd love to work on this issue. I'm a full-stack blockchain developer specializing in web apps and Smart Contracts, with experience in Next.js, TypeScript, Tailwind, and blockchain integration's and writing tests. I can handle this confidently, here's my portfolio and key projects:

• https://frontend-nine-mocha.vercel.app/
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Active OSS contributor.

[emwulrd]

I'd like to work on this issue.

I'll implement a new getVersion(client: ILNClient) method in the SDK that invokes the contract's get_version() view function and returns the deployed contract version as a Promise. I'll ensure the implementation gracefully handles cases where the contract is unavailable or the call fails, following the project's existing SDK error-handling patterns.

In addition, I'll add comprehensive unit tests using a mocked client, export the new method from sdk/src/index.ts, and include clear JSDoc documentation so frontend developers can easily use it for compatibility checks. I'll keep the implementation focused on the requested scope and align it with the project's existing architecture, coding standards, and contribution guidelines.

[grantfox-oss]

🦊 GrantFox — @emwulrd has been assigned to this issue as part of the Official Campaign | FWC26 campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #410)
2. Your PR will be reviewed by the Invoice-Liquidity-Network maintainers

Good luck! Track your progress on GrantFox.

[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox as part of the Official Campaign | FWC26 campaign!

@emwulrd's PR #446 was approved and merged by @Levi-Ojukwu.

🏆 @emwulrd: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (204 total points). Track your full progress on GrantFox.

👏 Great work, @emwulrd! Keep contributing to Invoice-Liquidity-Network.