I am a new to developing on NEAR and trying to create a FT smart contract, I haven’t learned Rust yet so I am using Javascript-Typescript but I am having this bug when I try to run some fucntion, the contract is deploying well, I can run init function well, but when I try to run other function that’s when I am getting the error below.
Here is the code:
import {
NearBindgen,
near,
call,
view,
initialize,
assert,
AccountId,
} from "near-sdk-js";
interface TokenMetadata {
name: string;
symbol: string;
decimals: number;
}
@NearBindgen({})
class FungibleTokenContract {
owner_id: string;
total_supply: number;
metadata:TokenMetadata;
balances: Map<string, number>;
constructor(owner_id: string, total_supply: number, metadata: TokenMetadata) {
this.owner_id = owner_id;
this.total_supply = total_supply;
this.metadata = metadata;
this.balances = new Map<string, number>();
}
@initialize({ privateFunction: true })
init(owner_id: string, total_supply: number, metadata: TokenMetadata): void {
this.owner_id = owner_id;
this.total_supply = total_supply;
this.metadata = metadata;
}
// Method to issue new tokens to a recipient
@call({})
issueTokens(recipient: string, amount: number): void {
let caller_id = near.predecessorAccountId();
assert(
caller_id === this.owner_id,
"Only the contract owner can issue tokens."
);
let recipientBalance = this.balances.get(recipient);
this.balances.set(recipient, recipientBalance + amount);
this.total_supply -= amount;
near.log(
`Issued ${amount} tokens to account: ${recipient}. Total supply: ${this.total_supply}`
);
}
// Method to retrieve token metadata
@view({})
tokenMetadata(): any {
return this.metadata;
}
// Method to transfer tokens from sender to recipient
@call({})
transferTokens(sender: string, recipient: string, amount: number): void {
let senderBalance = this.balances.get(sender);
assert(senderBalance >= amount, "Insufficient balance.");
this.balances.set(sender, senderBalance - amount);
let recipientBalance = this.balances.get(recipient);
this.balances.set(recipient, recipientBalance + amount);
near.log(`Transferred ${amount} tokens from ${sender} to ${recipient}.`);
}
// Method to distribute tokens as incentives/rewards
@call({})
distributeIncentives(account: string, amount: number): void {
let caller_id = near.predecessorAccountId();
assert(
caller_id === this.owner_id,
"Only the contract owner can distribute incentives."
);
let accountBalance = this.balances.get(account);
this.balances.set(account, accountBalance + amount);
this.total_supply -= amount;
near.log(
`Distributed ${amount} tokens to account: ${account}. Total supply: ${this.total_supply}`
);
}
// Method to get token balance for an account
@view({})
getTokenBalance(account: string): number {
return this.balances.get(account);
}
}
And this this is the full error message, when I run the getTokenBalance for exapmle, or the tokenMetadata :
near view $ID getTokenBalance '{"account": "'$ID'"}'
View call: dev-1685171425396-11051470732136.getTokenBalance({"account": "dev-1685171425396-11051470732136"})
An error occured
Error: Querying [object Object] failed: wasm execution failed with error: HostError(GuestPanic { panic_msg: "cannot read property 'constructor' of undefined\n at _reconstruct (build/hello_near.js:601)\n at getTokenBalance (build/hello_near.js:674)\n" }).
{
"block_hash": "Cz9sV5Vf9oy8d9gv2epNyKhZzvpd4PmXWmp4kYFahDqi",
"block_height": 127569024,
"error": "wasm execution failed with error: HostError(GuestPanic { panic_msg: \"cannot read property 'constructor' of undefined\\n at _reconstruct (build/hello_near.js:601)\\n at getTokenBalance (build/hello_near.js:674)\\n\" })",
"logs": []
}
at JsonRpcProvider.query (/home/enoch/.nvm/versions/node/v18.12.1/lib/node_modules/near-cli/node_modules/near-api-js/lib/providers/json-rpc-provider.js:123:19)
at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
at async Account.viewFunction (/home/enoch/.nvm/versions/node/v18.12.1/lib/node_modules/near-cli/node_modules/near-api-js/lib/account.js:366:24)
at async exports.callViewFunction (/home/enoch/.nvm/versions/node/v18.12.1/lib/node_modules/near-cli/index.js:103:48)
at async Object.handler (/home/enoch/.nvm/versions/node/v18.12.1/lib/node_modules/near-cli/utils/exit-on-error.js:52:9)
TypedError: Querying [object Object] failed: wasm execution failed with error: HostError(GuestPanic { panic_msg: "cannot read property 'constructor' of undefined\n at _reconstruct (build/hello_near.js:601)\n at getTokenBalance (build/hello_near.js:674)\n" }).
{
"block_hash": "Cz9sV5Vf9oy8d9gv2epNyKhZzvpd4PmXWmp4kYFahDqi",
"block_height": 127569024,
"error": "wasm execution failed with error: HostError(GuestPanic { panic_msg: \"cannot read property 'constructor' of undefined\\n at _reconstruct (build/hello_near.js:601)\\n at getTokenBalance (build/hello_near.js:674)\\n\" })",
"logs": []
}
at JsonRpcProvider.query (/home/enoch/.nvm/versions/node/v18.12.1/lib/node_modules/near-cli/node_modules/near-api-js/lib/providers/json-rpc-provider.js:123:19)
at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
at async Account.viewFunction (/home/enoch/.nvm/versions/node/v18.12.1/lib/node_modules/near-cli/node_modules/near-api-js/lib/account.js:366:24)
at async exports.callViewFunction (/home/enoch/.nvm/versions/node/v18.12.1/lib/node_modules/near-cli/index.js:103:48)
at async Object.handler (/home/enoch/.nvm/versions/node/v18.12.1/lib/node_modules/near-cli/utils/exit-on-error.js:52:9) {
type: 'UntypedError',
context: undefined
}
