Implement unit tests for credential-nft contract (tests/unit/credential_tests.rs)

[DeFiVC]

Description

The file tests/unit/credential_tests.rs contains 8 test function skeletons for the credential-nft contract. All assertions are commented out. The goal is to uncomment and complete these tests.

How to set up each test

1. Create Env::default()
2. Generate admin: let admin = Address::generate(&env);
3. Register: let contract_id = env.register(CredentialNft, ());
4. Create client: let client = CredentialNftClient::new(&env, &contract_id);
5. Initialize: client.initialize(&admin);
6. Call env.mock_all_auths();

Reference: inline tests at contracts/credential-nft/src/lib.rs:92-201.

Tests to uncomment and complete

test_mint_requires_passing_score

What it verifies: #[should_panic(expected = "score 40 below minimum threshold 50")] — score < 50 (MIN_CREDENTIAL_SCORE) panics.

let learner = Address::generate(&env);
env.mock_all_auths();
let course_id = Symbol::new(&env, "rust_101");
let uri = Symbol::new(&env, "ipfs://Qm123");
client.mint_credential(&learner, &course_id, &40, &uri);  // panics

test_mint_with_valid_score

What it verifies: Minting with score 85 succeeds. verify_credential returns correct info.

let cred_id = client.mint_credential(&learner, &course_id, &85, &metadata_uri);
assert_eq!(cred_id, 1);
let info = client.verify_credential(&cred_id);
assert_eq!(info.learner, learner);
assert_eq!(info.course_id, course_id);
assert_eq!(info.score, 85);
assert!(!info.revoked);

test_prevent_duplicate_credentials

What it verifies: #[should_panic(expected = "credential already exists for this learner and course")] — minting twice for same learner+course panics.

client.mint_credential(&learner, &course_id, &90, &uri);
client.mint_credential(&learner, &course_id, &95, &uri);  // panics

test_get_credentials_for_learner

What it verifies: After minting 2 credentials for different courses, get_credentials_for(&learner) returns 2 IDs.

let course1 = Symbol::new(&env, "rust_101");
let course2 = Symbol::new(&env, "sol_201");
let uri = Symbol::new(&env, "ipfs://meta");
client.mint_credential(&learner, &course1, &90, &uri);
client.mint_credential(&learner, &course2, &75, &uri);
let creds = client.get_credentials_for(&learner);
assert_eq!(creds.len(), 2);

test_revoke_credential

What it verifies: After minting, is_credential_valid returns true. After revoking, it returns false and verify_credential shows revoked: true.

let cred_id = client.mint_credential(&learner, &course_id, &80, &uri);
assert!(client.is_credential_valid(&cred_id));
client.revoke_credential(&cred_id);
assert!(!client.is_credential_valid(&cred_id));
let info = client.verify_credential(&cred_id);
assert!(info.revoked);

test_double_revoke

What it verifies: #[should_panic(expected = "credential already revoked")] — revoking twice panics.

let cred_id = client.mint_credential(&learner, &course_id, &80, &uri);
client.revoke_credential(&cred_id);
client.revoke_credential(&cred_id);  // panics

test_nonexistent_credential_invalid

What it verifies: is_credential_valid(&999) returns false for a credential that was never minted.

assert!(!client.is_credential_valid(&999));

test_credential_id_increment

What it verifies: Two mints for different learners return IDs 1 and 2 respectively.

let id1 = client.mint_credential(&learner1, &course, &80, &uri);
let id2 = client.mint_credential(&learner2, &course, &90, &uri);
assert_eq!(id1, 1);
assert_eq!(id2, 2);

Imports needed

use credential_nft::{CredentialNft, CredentialNftClient};
use soroban_sdk::{testutils::Address as _, Address, Env, Symbol};

How to run

cd chainlearn-contracts
cargo test --package credential-nft --test credential_tests

References

• Contract source: contracts/credential-nft/src/lib.rs (201 lines)
• Minting logic: contracts/credential-nft/src/mint.rs — score gate at line 32: if score < MIN_CREDENTIAL_SCORE
• Verification: contracts/credential-nft/src/verify.rs
• Data types: contracts/credential-nft/src/metadata.rs — CredentialInfo struct with fields: learner, course_id, score, issued_at, revoked, metadata_uri
• Constants: packages/shared/src/constants.rs — MIN_CREDENTIAL_SCORE = 50

[Codekill33]

Hello, i have solid experience with smart contracts, I'd like to complete the 8 credential NFT test skeletons by implementing the missing assertions and test logic for minting, score validation, duplicate prevention, revocation, credential lookup, and ID incrementation, ensuring all tests pass successfully.
Kindly assign me to this issue. Thank you.