Add UniswapV2 support (#375)

* Add UniswapV2 support

* Bump package version

* Test fix

* Fix comment

* Fix comment

* Advance time to fix test fail

.gitignore

@@ -6,3 +6,5 @@ build/
 /.coverage_contracts/
 coverage.json
 yarn.lock
+
+tenderly.yaml

package.json

@@ -1,6 +1,6 @@
 {
   "name": "hardlydifficult-eth",
-  "version": "1.0.0",
+  "version": "1.1.0",
   "description": "A collection of reusable contracts and Javascript helpers for Ethereum.",
   "scripts": {
     "build": "npm run compile",
@@ -9,7 +9,7 @@
     "lint": "solium -d contracts --fix && eslint . --fix",
     "lintNoFix": "solium -d contracts && eslint .",
     "coverage": "truffle run coverage && cat coverage/lcov.info | coveralls",
-    "ganache": "ganache-cli"
+    "ganache": "ganache-cli -e 10000000000"
   },
   "files": [
     "build",
@@ -44,6 +44,7 @@
   },
   "devDependencies": {
     "@codechecks/client": "0.1.10",
+    "@openzeppelin/test-helpers": "0.5.6",
     "coveralls": "3.1.0",
     "eslint": "7.1.0",
     "eslint-config-prettier": "6.11.0",

src/protocols/index.js

@@ -1,4 +1,5 @@
 module.exports = {
   unlock: require("./unlock"),
-  uniswap: require("./uniswap"),
+  uniswapV1: require("./uniswapV1"),
+  uniswapV2: require("./uniswapV2"),
 };

src/protocols/uniswap.js → src/protocols/uniswapV1.js

@@ -1,5 +1,5 @@
 const { truffleContract } = require("../helpers");
-const uniswapJson = require("./uniswap.json");
+const uniswapJson = require("./uniswapV1.json");
 
 module.exports = {
   mainnetFactoryAddress: "0xc0a47dfe034b400b47bdad5fecda2621de6c4d95",

src/protocols/uniswapV2.js

@@ -0,0 +1,47 @@
+const { truffleContract } = require("../helpers");
+const uniswapJson = require("./uniswapV2.json");
+
+module.exports = {
+  mainnetFactoryAddress: "0x5C69bEe701ef814a2B6a3EDD4B1652CB9cc5aA6f",
+  mainnetRouterAddress: "0xf164fC0Ec4E93095b804a4795bBe1e041497b92a",
+  /**
+   * Deploys the Uniswap factory and router.
+   * @param feeSetter allows a fee to be enabled. May be address(0)
+   * @param wethAddress the address of the WETH token (used by the router)
+   * @returns the Uniswap router as a truffleContract object
+   * This is useful for testing on Ganache
+   */
+  deploy: async (web3, owner, feeSetter, wethAddress) => {
+    const factory = await truffleContract.new(
+      web3,
+      uniswapJson.abi,
+      `0x${uniswapJson.bytecode.replace(/0x/, "")}`,
+      owner,
+      feeSetter
+    );
+
+    const router = await truffleContract.new(
+      web3,
+      uniswapJson.router.abi,
+      `0x${uniswapJson.router.bytecode.replace(/0x/, "")}`,
+      owner,
+      factory.address,
+      wethAddress
+    );
+
+    return router;
+  },
+  getFactory: async (web3, factoryAddress) => {
+    return await truffleContract.at(web3, uniswapJson.abi, factoryAddress);
+  },
+  getRouter: async (web3, routerAddress) => {
+    return await truffleContract.at(
+      web3,
+      uniswapJson.router.abi,
+      routerAddress
+    );
+  },
+  getPair: async (web3, pairAddress) => {
+    return await truffleContract.at(web3, uniswapJson.pair.abi, pairAddress);
+  },
+};

src/tokens/index.js

@@ -3,4 +3,5 @@ module.exports = {
   dai: require("./dai"),
   sai: require("./sai"),
   usdc: require("./usdc"),
+  weth: require("./weth"),
 };

src/tokens/weth.js

@@ -0,0 +1,22 @@
+const { truffleContract } = require("../helpers");
+const wethJson = require("./weth.json");
+
+async function getToken(web3, tokenAddress) {
+  return await truffleContract.at(web3, wethJson.abi, tokenAddress);
+}
+
+module.exports = {
+  mainnetAddress: "0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2",
+  decimals: 18,
+  deploy: async (web3, from) => {
+    const result = await truffleContract.new(
+      web3,
+      wethJson.abi,
+      `0x${wethJson.bytecode.replace(/0x/, "")}`,
+      from
+    );
+
+    return result;
+  },
+  getToken,
+};

src/tokens/weth.json

@@ -0,0 +1,4 @@
+{
+  "abi": [{"constant":true,"inputs":[],"name":"name","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"guy","type":"address"},{"name":"wad","type":"uint256"}],"name":"approve","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"totalSupply","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"src","type":"address"},{"name":"dst","type":"address"},{"name":"wad","type":"uint256"}],"name":"transferFrom","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"wad","type":"uint256"}],"name":"withdraw","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"decimals","outputs":[{"name":"","type":"uint8"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"","type":"address"}],"name":"balanceOf","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"symbol","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"dst","type":"address"},{"name":"wad","type":"uint256"}],"name":"transfer","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[],"name":"deposit","outputs":[],"payable":true,"stateMutability":"payable","type":"function"},{"constant":true,"inputs":[{"name":"","type":"address"},{"name":"","type":"address"}],"name":"allowance","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"payable":true,"stateMutability":"payable","type":"fallback"},{"anonymous":false,"inputs":[{"indexed":true,"name":"src","type":"address"},{"indexed":true,"name":"guy","type":"address"},{"indexed":false,"name":"wad","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"src","type":"address"},{"indexed":true,"name":"dst","type":"address"},{"indexed":false,"name":"wad","type":"uint256"}],"name":"Transfer","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"dst","type":"address"},{"indexed":false,"name":"wad","type":"uint256"}],"name":"Deposit","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"src","type":"address"},{"indexed":false,"name":"wad","type":"uint256"}],"name":"Withdrawal","type":"event"}],
+  "bytecode": "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+}

test/protocols/uniswap.js → test/protocols/uniswapV1.js

@@ -1,20 +1,20 @@
 const { tokens, protocols } = require("../..");
 
-contract("protocols / uniswap", (accounts) => {
+contract("protocols / uniswapV1", (accounts) => {
   const protocolOwner = accounts[0];
   let uniswap;
   let sai;
 
   before(async () => {
-    uniswap = await protocols.uniswap.deploy(web3, protocolOwner);
+    uniswap = await protocols.uniswapV1.deploy(web3, protocolOwner);
     sai = await tokens.sai.deploy(web3, protocolOwner);
   });
 
   it("Can create an exchange and add liquidity", async () => {
     const tx = await uniswap.createExchange(sai.address, {
       from: protocolOwner,
     });
-    const exchange = await protocols.uniswap.getExchange(
+    const exchange = await protocols.uniswapV1.getExchange(
       web3,
       tx.logs[0].args.exchange
     );

test/protocols/uniswapV2.js

@@ -0,0 +1,75 @@
+const { constants, tokens, protocols } = require("../..");
+const { time } = require("@openzeppelin/test-helpers");
+
+contract("protocols / uniswapV2", (accounts) => {
+  const protocolOwner = accounts[9];
+  let uniswapRouter;
+  let dai, weth;
+
+  beforeEach(async () => {
+    dai = await tokens.dai.deploy(web3, protocolOwner);
+    weth = await tokens.weth.deploy(web3, protocolOwner);
+    uniswapRouter = await protocols.uniswapV2.deploy(
+      web3,
+      protocolOwner,
+      constants.ZERO_ADDRESS,
+      weth.address
+    );
+  });
+
+  describe("create a pair", () => {
+    const liquidityOwner = accounts[1];
+
+    beforeEach(async () => {
+      await dai.mint(liquidityOwner, web3.utils.toWei("100000", "ether"), {
+        from: protocolOwner,
+      });
+      await dai.approve(uniswapRouter.address, constants.MAX_UINT, {
+        from: liquidityOwner,
+      });
+      await uniswapRouter.addLiquidityETH(
+        dai.address,
+        web3.utils.toWei("2000", "ether"),
+        "1",
+        "1",
+        liquidityOwner,
+        constants.MAX_UINT,
+        { from: liquidityOwner, value: web3.utils.toWei("10", "ether") }
+      );
+    });
+
+    it("can read exchange rate", async () => {
+      const rate = (
+        await uniswapRouter.getAmountsOut(web3.utils.toWei("1", "ether"), [
+          dai.address,
+          weth.address,
+        ])
+      )[1];
+      // 1 DAI is worth ~0.004 ETH
+      assert.equal(rate.toString(), "4982516215666490");
+    });
+
+    describe("swap tokens", () => {
+      const trader = accounts[2];
+
+      beforeEach(async () => {
+        // Advancing time to avoid an intermittent test fail
+        await time.increase(time.duration.hours(1));
+
+        await uniswapRouter.swapExactETHForTokens(
+          1,
+          [weth.address, dai.address],
+          trader,
+          constants.MAX_UINT,
+          { from: trader, value: web3.utils.toWei("1", "ether") }
+        );
+      });
+
+      it("got dai from the swap", async () => {
+        const balance = await dai.balanceOf(trader);
+        // 1 ETH is worth ~180 DAI
+        assert.equal(balance.toString(), "181322178776029826316");
+      });
+    });
+  });
+});

test/tokens/weth.js

@@ -0,0 +1,18 @@
+const { tokens } = require("../..");
+
+contract("tokens / WETH", (accounts) => {
+  let token;
+
+  beforeEach(async () => {
+    // The from address is not relevant for this token
+    token = await tokens.weth.deploy(web3, accounts[9]);
+  });
+
+  it("Can deposit", async () => {
+    const account = accounts[1];
+    const value = web3.utils.toWei("4.2", "ether");
+    await token.deposit({ from: account, value });
+    const balance = await token.balanceOf(account);
+    assert.equal(balance.toString(), value);
+  });
+});