feat: type and use callContract

closes #6

__tests__/contracts.test.ts

@@ -1,5 +1,13 @@
+import { BigNumber } from '@ethersproject/bignumber';
 import fs from 'fs';
-import { CompiledContract, Contract, deployContract, JsonParser, randomAddress } from '../src';
+import {
+  CompiledContract,
+  Contract,
+  deployContract,
+  JsonParser,
+  randomAddress,
+  waitForTx,
+} from '../src';
 
 const compiledERC20: CompiledContract = JsonParser.parse(
   fs.readFileSync('./__mocks__/ERC20.json').toString('ascii')
@@ -16,8 +24,15 @@ describe('new Contract()', () => {
     // eslint-disable-next-line no-console
     console.log('deployed erc20 contract', tx_id);
     expect(code).toBe('TRANSACTION_RECEIVED');
+    await waitForTx(tx_id);
   });
-  test('initialize ERC20 mock contract', async () => {
+  test('read initial balance of that account', async () => {
+    const response = await contract.call('balance_of', {
+      user: wallet,
+    });
+    expect(BigNumber.from(response.res)).toStrictEqual(BigNumber.from(0));
+  });
+  test('add 10 test ERC20 to account', async () => {
     const response = await contract.invoke('mint', {
       recipient: wallet,
       amount: '10',
@@ -27,5 +42,13 @@ describe('new Contract()', () => {
     // I want to show the tx number to the tester, so he/she can trace the transaction in the explorer.
     // eslint-disable-next-line no-console
     console.log('txId:', response.tx_id, ', funded wallet:', wallet);
+    await waitForTx(response.tx_id);
+  });
+  test('read balance after mint of that account', async () => {
+    const response = await contract.call('balance_of', {
+      user: wallet,
+    });
+
+    expect(BigNumber.from(response.res)).toStrictEqual(BigNumber.from(10));
   });
 });

package.json

@@ -66,6 +66,6 @@
     "*.{ts,js,md,yml,json}": "prettier --write"
   },
   "jest": {
-    "testTimeout": 20000
+    "testTimeout": 300000
   }
 }

src/contract.ts

@@ -2,7 +2,7 @@ import assert from 'assert';
 import { BigNumber } from '@ethersproject/bignumber';
 import { Abi } from './types';
 import { getSelectorFromName } from './utils';
-import { addTransaction } from './starknet';
+import { addTransaction, callContract } from './starknet';
 
 type Args = { [inputName: string]: string | string[] };
 type Calldata = string[];
@@ -56,19 +56,19 @@ export class Contract {
     });
   }
 
-  public invoke(method: string, args: Args = {}) {
-    // ensure contract is connected
-    assert(this.connectedTo !== null, 'contract isnt connected to an address');
-
+  private validateMethodAndArgs(type: 'INVOKE' | 'CALL', method: string, args: Args = {}) {
     // ensure provided method exists
     const invokeableFunctionNames = this.abi
       .filter((abi) => {
         const isView = abi.stateMutability === 'view';
         const isFunction = abi.type === 'function';
-        return isFunction && !isView;
+        return isFunction && type === 'INVOKE' ? !isView : isView;
       })
       .map((abi) => abi.name);
-    assert(invokeableFunctionNames.includes(method), 'invokeable method not found in abi');
+    assert(
+      invokeableFunctionNames.includes(method),
+      `${type === 'INVOKE' ? 'invokeable' : 'viewable'} method not found in abi`
+    );
 
     // ensure args match abi type
     const methodAbi = this.abi.find((abi) => abi.name === method)!;
@@ -94,6 +94,24 @@ export class Contract {
         });
       }
     });
+  }
+
+  private parseResponse(method: string, response: (string | string[])[]): Args {
+    const methodAbi = this.abi.find((abi) => abi.name === method)!;
+    return methodAbi.outputs.reduce((acc, output, i) => {
+      return {
+        ...acc,
+        [output.name]: response[i],
+      };
+    }, {} as Args);
+  }
+
+  public invoke(method: string, args: Args = {}) {
+    // ensure contract is connected
+    assert(this.connectedTo !== null, 'contract isnt connected to an address');
+
+    // validate method and args
+    this.validateMethodAndArgs('INVOKE', method, args);
 
     // compile calldata
     const entrypointSelector = getSelectorFromName(method);
@@ -106,4 +124,22 @@ export class Contract {
       entry_point_selector: entrypointSelector,
     });
   }
+
+  public async call(method: string, args: Args = {}) {
+    // ensure contract is connected
+    assert(this.connectedTo !== null, 'contract isnt connected to an address');
+
+    // validate method and args
+    this.validateMethodAndArgs('CALL', method, args);
+
+    // compile calldata
+    const entrypointSelector = getSelectorFromName(method);
+    const calldata = Contract.compileCalldata(args);
+
+    return callContract({
+      contract_address: this.connectedTo,
+      calldata,
+      entry_point_selector: entrypointSelector,
+    }).then((x) => this.parseResponse(method, x.result));
+  }
 }

src/starknet.ts

@@ -9,6 +9,8 @@ import type {
   Transaction,
   AddTransactionResponse,
   CompiledContract,
+  Call,
+  CallContractResponse,
 } from './types';
 
 const API_URL = 'https://alpha2.starknet.io';
@@ -32,20 +34,19 @@ export function getContractAddresses(): Promise<GetContractAddressesResponse> {
   });
 }
 
-// TODO: add proper type
 /**
  * Calls a function on the StarkNet contract.
  *
  * [Reference](https://github.com/starkware-libs/cairo-lang/blob/f464ec4797361b6be8989e36e02ec690e74ef285/src/starkware/starknet/services/api/feeder_gateway/feeder_gateway_client.py#L17-L25)
  *
- * @param invokeTx - transaction to be invoked (WIP)
+ * @param invokeTx - transaction to be invoked
  * @param blockId
  * @returns the result of the function on the smart contract.
  */
-export function callContract(invokeTx: object, blockId: number): Promise<object> {
+export function callContract(invokeTx: Call, blockId?: number): Promise<CallContractResponse> {
   return new Promise((resolve, reject) => {
     axios
-      .post(`${FEEDER_GATEWAY_URL}/call_contract?blockId=${blockId}`, invokeTx)
+      .post(`${FEEDER_GATEWAY_URL}/call_contract?blockId=${blockId ?? 'null'}`, invokeTx)
       .then((resp: any) => {
         resolve(resp.data);
       })
@@ -167,7 +168,7 @@ export function getTransaction(txId: number): Promise<GetTransactionResponse> {
  *
  * [Reference](https://github.com/starkware-libs/cairo-lang/blob/f464ec4797361b6be8989e36e02ec690e74ef285/src/starkware/starknet/services/api/gateway/gateway_client.py#L13-L17)
  *
- * @param tx - transaction to be invoked (WIP)
+ * @param tx - transaction to be invoked
  * @returns a confirmation of invoking a function on the starknet contract
  */
 export function addTransaction(tx: Transaction): Promise<AddTransactionResponse> {
@@ -206,7 +207,27 @@ export function deployContract(
   });
 }
 
+const wait = (delay: number) => new Promise((res) => setTimeout(res, delay));
+export async function waitForTx(txId: number, retryInterval: number = 2000) {
+  let onchain = false;
+  while (!onchain) {
+    // eslint-disable-next-line no-await-in-loop
+    const res = await getTransactionStatus(txId);
+    if (res.tx_status === 'ACCEPTED_ONCHAIN' || res.tx_status === 'PENDING') {
+      onchain = true;
+    } else if (res.tx_status === 'REJECTED') {
+      throw Error('REJECTED');
+    } else if (res.tx_status === 'NOT_RECEIVED') {
+      throw Error('NOT_RECEIVED');
+    } else {
+      // eslint-disable-next-line no-await-in-loop
+      await wait(retryInterval);
+    }
+  }
+}
+
 export default {
+  waitForTx,
   getContractAddresses,
   callContract,
   getBlock,

src/types.ts

@@ -12,7 +12,7 @@ export type CompressedProgram = string;
 export interface Abi {
   inputs: { name: string; type: 'felt' | 'felt*' }[];
   name: string;
-  outputs: { name: string; type: string }[];
+  outputs: { name: string; type: 'felt' | 'felt*' }[];
   stateMutability?: 'view';
   type: 'function';
 }
@@ -43,8 +43,14 @@ export interface InvokeFunctionTransaction {
   calldata?: string[];
 }
 
+export type Call = Omit<InvokeFunctionTransaction, 'type'>;
+
 export type Transaction = DeployTransaction | InvokeFunctionTransaction;
 
+export interface CallContractResponse {
+  result: string[];
+}
+
 export interface GetBlockResponse {
   sequence_number: number;
   state_root: string;