add test and fix build options

Author: mconcat

__fixtures__/amm/src/contract.js

@@ -0,0 +1,197 @@
+import { getBalance, sendCoins } from 'bank';
+
+const store = (storeDefinition) => {
+  return (target, state) => {
+    Object.entries(storeDefinition).forEach(([key, value]) => {
+      if (typeof value === 'function') {
+        // For functions, create a getter and a setter
+        Object.defineProperty(target, key, {
+          get() {
+            return (...args) => state.get([key, ...args].join('/')) ?? value(undefined); // TODO: support nested mappings
+          },
+          enumerable: true,
+        });
+  
+        const setterName = `set${key.charAt(0).toUpperCase() + key.slice(1)}`;
+        Object.defineProperty(target, setterName, {
+          value: (...args) => {
+            const newValue = args[args.length - 1];
+            const keys = args.slice(0, -1);
+            state.set([key, ...keys].join('/'), newValue);
+          },
+          enumerable: false,
+        });
+      } else {
+        // For non-functions, create a getter and a setter
+        Object.defineProperty(target, key, {
+          get() {
+            return state.get(key) ?? value;
+          },
+          set(newValue) {
+            state.set(key, newValue);
+          },
+          enumerable: true,
+        });
+
+        const setterName = `set${key.charAt(0).toUpperCase() + key.slice(1)}`;
+        Object.defineProperty(target, setterName, {
+          value: (newValue) => {
+            state.set(key, newValue);
+          },
+          enumerable: false,
+        });
+      }
+    });
+  };
+};
+
+//////////////////////////////////////////////////////////////////////////////////
+
+const useStore = store({
+  totalSupply: 0,
+  balance:address => 0,
+  reserves: [0, 0],
+});
+// should construct
+// this.totalSupply // getter
+// this.setTotalSupply(value) // setter
+// this.balance(address) // getter
+// this.setBalance(address, value) // setter
+// this.reserves // getter
+// this.setReserves(value) // setter
+export default class AMMContract {
+  constructor(state, {msg, address}) {
+    this.msg = msg;
+    this.address = address;
+
+    useStore(this, state);
+  }
+
+  token0 = 'USDC';
+  token1 = 'ATOM';
+
+  getTotalSupply() {
+    return this.totalSupply;
+  }
+
+  getBalance(address) {
+    return this.balance(address);
+  }
+
+  getReserves() {
+    return this.reserves;
+  }
+
+  #getBankBalance(address, token) {
+    return getBalance(address, token);
+  }
+
+  #mint(to, amount) {
+    const balance = this.balance(to);
+    this.setBalance(to, balance + amount);
+    this.totalSupply += amount;
+  }
+
+  #burn(from, amount) {
+    const balance = this.balance(from);
+    if (balance < amount) {
+      throw Error('insufficient balance');
+    }
+    this.setBalance(from, balance - amount);
+    this.totalSupply -= amount;
+  }
+
+  #update(amount0, amount1) {
+    const [reserve0, reserve1] = this.reserves;
+    this.reserves = [
+      reserve0 + amount0,
+      reserve1 + amount1,
+    ];
+  }
+
+  swap({tokenIn, amountIn}) {
+    const isToken0 = tokenIn == this.token0;
+    const isToken1 = tokenIn == this.token1;
+
+    if (!isToken0 && !isToken1) {
+      throw Error('invalid token');
+    }
+
+    const [reserve0, reserve1] = this.reserves;
+    let tokenOut, reserveIn, reserveOut;
+
+    [tokenIn, tokenOut, reserveIn, reserveOut] = 
+            isToken0 
+              ? [this.token0, this.token1, reserve0, reserve1]
+              : [this.token1, this.token0, reserve1, reserve0];
+
+    sendCoins(this.msg.sender, this.address, {
+      [tokenIn]: amountIn,
+    });
+
+    const amountInWithFee = amountIn * 997 / 1000;
+    const amountOut = (reserveOut * amountInWithFee) / (reserveIn + amountInWithFee);
+
+    sendCoins(this.address, this.msg.sender, {
+      [tokenOut]: amountOut,
+    });
+
+    this.#update(
+      this.#getBankBalance(this.address, this.token0).amount, 
+      this.#getBankBalance(this.address, this.token1).amount,
+    );
+
+    return amountOut;
+  }
+
+  addLiquidity({amount0, amount1}) {
+    sendCoins(this.msg.sender, this.address, {
+      [this.token0]: amount0,
+      [this.token1]: amount1,
+    });
+
+    const [reserve0, reserve1] = this.reserves;
+
+    if (reserve0 > 0 || reserve1 > 0) {
+      if (reserve0 * amount1 != reserve1 * amount0) {
+        throw Error('invalid liquidity');
+      }
+    }
+
+    let shares = 0;
+    if (this.totalSupply > 0) {
+      shares = Math.sqrt(amount0 * amount1);
+    } else {
+      shares = Math.min(
+        (amount0 * this.totalSupply) / reserve0,
+        (amount1 * this.totalSupply) / reserve1,
+      );
+    }
+
+    this.#mint(this.msg.sender, shares);
+
+    this.#update(
+      this.#getBankBalance(this.address, this.token0).amount,
+      this.#getBankBalance(this.address, this.token1).amount,
+    );
+
+    return shares;
+  }
+
+  removeLiquidity({shares}) {
+    const bal0 = this.#getBankBalance(this.address, this.token0);
+    const bal1 = this.#getBankBalance(this.address, this.token1);
+    const totalSupply = this.totalSupply;
+
+    const amount0 = bal0 * shares / totalSupply;
+    const amount1 = bal1 * shares / totalSupply;
+    this.#burn(this.msg.sender, shares);
+    this.#update(bal0 - amount0, bal1 - amount1);
+    sendCoins(this.address, this.msg.sender, {
+      [this.token0]: amount0,
+      [this.token1]: amount1,
+    });
+
+    return [amount0, amount1];
+  }
+}

__fixtures__/amm/src/index.js

@@ -0,0 +1,53 @@
+// top level middleware for JSD contracts
+
+import * as contract from './contract.js';
+
+function contractNamespaceObject() {
+  // iterate over all properties of the contract object
+  // ESM modules are not enumerable, use getOwnPropertyNames
+  const exports = {};
+
+  for (const key of Object.getOwnPropertyNames(contract)) {
+    if (key === 'default') {
+      continue;
+    }
+
+    exports[key] = contract[key];
+  }
+
+  return exports;
+}
+
+function callClassContract(state, functionName, body) {
+  const instance = new contract.default(state, {msg: {sender: state.sender}, address: state.self});
+
+  return instance[functionName](body);
+}
+
+export default function(state, functionName, body) {
+  if (typeof functionName !== 'string') {
+    return new Error('contract function name must be a string, got ' + typeof functionName);
+  }
+
+  // module 'contract' exports contract as a class via the default export
+  // TODO: check if contract is a class or just a function
+  if (contract.default && typeof contract.default === 'function') {
+    return callClassContract(state, functionName, body);
+  }
+
+  const entry = contractNamespaceObject()[functionName];
+
+  if (typeof entry === 'undefined') {
+    return new Error('contract function ' + functionName + ' not found: got undefined');
+  }
+
+  if (typeof entry !== 'function' && !body) {
+    return entry;
+  }
+
+  if (typeof entry === 'function') {
+    return entry(state, body);
+  }
+
+  return new Error('contract function' + functionName + ' not found: got ' + typeof entry);
+}