aave-protocol-v2/test/helpers/scenario-engine.ts

import {TestEnv, SignerWithAddress} from './make-suite';
import {
  mint,
  approve,
  deposit,
  borrow,
  withdraw,
  repay,
  setUseAsCollateral,
  swapBorrowRateMode,
  rebalanceStableBorrowRate
} from './actions';
import {RateMode} from '../../helpers/types';

export interface Action {
  name: string;
  args?: any;
  expected: string;
  revertMessage?: string;
}

export interface Story {
  description: string;
  actions: Action[];
}

export interface Scenario {
  title: string;
  description: string;
  stories: Story[];
}

export const executeStory = async (story: Story, testEnv: TestEnv) => {
  for (const action of story.actions) {
    const {users} = testEnv;
    await executeAction(action, users, testEnv);
  }
};

const executeAction = async (action: Action, users: SignerWithAddress[], testEnv: TestEnv) => {
  const {reserve, user: userIndex, borrowRateMode} = action.args;
  const {name, expected, revertMessage} = action;

  if (!name || name === '') {
    throw 'Action name is missing';
  }
  if (!reserve || reserve === '') {
    throw 'Invalid reserve selected for deposit';
  }
  if (!userIndex || userIndex === '') {
    throw `Invalid user selected to deposit into the ${reserve} reserve`;
  }

  if (!expected || expected === '') {
    throw `An expected resut for action ${name} is required`;
  }

  let rateMode: string = RateMode.None;

  if (borrowRateMode) {
    if (borrowRateMode === 'none') {
      RateMode.None;
    } else if (borrowRateMode === 'stable') {
      rateMode = RateMode.Stable;
    } else if (borrowRateMode === 'variable') {
      rateMode = RateMode.Variable;
    } else {
      //random value, to test improper selection of the parameter
      rateMode = '4';
    }
  }

  const user = users[parseInt(userIndex)];

  switch (name) {
    case 'mint':
      const {amount} = action.args;

      if (!amount || amount === '') {
        throw `Invalid amount of ${reserve} to mint`;
      }

      await mint(reserve, amount, user);
      break;

    case 'approve':
      await approve(reserve, user, testEnv);
      break;

    case 'deposit':
      {
        const {amount, sendValue, onBehalfOf: onBehalfOfIndex} = action.args;
        const onBehalfOf = onBehalfOfIndex
          ? users[parseInt(onBehalfOfIndex)].address
          : user.address;

        if (!amount || amount === '') {
          throw `Invalid amount to deposit into the ${reserve} reserve`;
        }

        await deposit(
          reserve,
          amount,
          user,
          onBehalfOf,
          sendValue,
          expected,
          testEnv,
          revertMessage
        );
      }
      break;

    case 'withdraw':
      {
        const {amount} = action.args;

        if (!amount || amount === '') {
          throw `Invalid amount to withdraw from the ${reserve} reserve`;
        }

        await withdraw(reserve, amount, user, expected, testEnv, revertMessage);
      }
      break;
    case 'borrow':
      {
        const {amount, timeTravel} = action.args;

        if (!amount || amount === '') {
          throw `Invalid amount to borrow from the ${reserve} reserve`;
        }

        await borrow(reserve, amount, rateMode, user, timeTravel, expected, testEnv, revertMessage);
      }
      break;

    case 'repay':
      {
        const {amount, borrowRateMode, sendValue} = action.args;
        let {onBehalfOf: onBehalfOfIndex} = action.args;

        if (!amount || amount === '') {
          throw `Invalid amount to repay into the ${reserve} reserve`;
        }

        let userToRepayOnBehalf: SignerWithAddress;
        if (!onBehalfOfIndex || onBehalfOfIndex === '') {
          console.log(
            'WARNING: No onBehalfOf specified for a repay action. Defaulting to the repayer address'
          );
          userToRepayOnBehalf = user;
        } else {
          userToRepayOnBehalf = users[parseInt(onBehalfOfIndex)];
        }

        await repay(
          reserve,
          amount,
          rateMode,
          user,
          userToRepayOnBehalf,
          sendValue,
          expected,
          testEnv,
          revertMessage
        );
      }
      break;

    case 'setUseAsCollateral':
      {
        const {useAsCollateral} = action.args;

        if (!useAsCollateral || useAsCollateral === '') {
          throw `A valid value for useAsCollateral needs to be set when calling setUseReserveAsCollateral on reserve ${reserve}`;
        }
        await setUseAsCollateral(reserve, user, useAsCollateral, expected, testEnv, revertMessage);
      }
      break;

    case 'swapBorrowRateMode':
      await swapBorrowRateMode(reserve, user, rateMode, expected, testEnv, revertMessage);
      break;

    case 'rebalanceStableBorrowRate':
      {
        const {target: targetIndex} = action.args;

        if (!targetIndex || targetIndex === '') {
          throw `A target must be selected when trying to rebalance a stable rate`;
        }
        const target = users[parseInt(targetIndex)];

        await rebalanceStableBorrowRate(reserve, user, target, expected, testEnv, revertMessage);
      }
      break;
   
    default:
      throw `Invalid action requested: ${name}`;
  }
};