Update price evm Oracle Example (#1411)

Author: aditya520

target_chains/ethereum/examples/oracle_swap/README.md

@@ -17,14 +17,20 @@ All of the commands in this section expect to be run from the `contract` directo
 ### Building
 
 You need to have [Foundry](https://getfoundry.sh/) and `node` installed to run this example.
-Once you have installed these tools, run the following commands from the [`contract`](./contract) directory:
+Once you have installed these tools, run the following commands from the [`contract`](./contract) directory to install openzeppelin and forge dependencies:
 
 ```
-forge install foundry-rs/forge-std@2c7cbfc6fbede6d7c9e6b17afe997e3fdfe22fef --no-git --no-commit
-forge install pyth-network/[email protected] --no-git --no-commit
+forge install foundry-rs/[email protected] --no-git --no-commit
 forge install OpenZeppelin/[email protected] --no-git --no-commit
 ```
 
+After installing the above dependencies, you need to install pyth-sdk-solidity.
+
+```
+npm init -y
+npm install @pythnetwork/pyth-sdk-solidity
+```
+
 ### Testing
 
 Simply run `forge test` in the [`contract`](./contract) directory. This command will run the

target_chains/ethereum/examples/oracle_swap/contract/package-lock.json

@@ -0,0 +1,19 @@
+{
+  "name": "contract",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "directories": {
+    "lib": "lib",
+    "test": "test"
+  },
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "@pythnetwork/pyth-sdk-solidity": "^3.0.0"
+  }
+}

target_chains/ethereum/examples/oracle_swap/contract/package.json

@@ -1,4 +1,5 @@
-ds-test/=lib/forge-std/lib/ds-test/src/
+ds-test/=lib/openzeppelin-contracts/lib/forge-std/lib/ds-test/src/
+erc4626-tests/=lib/openzeppelin-contracts/lib/erc4626-tests/
 forge-std/=lib/forge-std/src/
-pyth-sdk-solidity/=lib/pyth-sdk-solidity/
 openzeppelin-contracts/=lib/openzeppelin-contracts/
+@pythnetwork=node_modules/@pythnetwork

target_chains/ethereum/examples/oracle_swap/contract/remappings.txt

@@ -1,8 +1,9 @@
 // SPDX-License-Identifier: UNLICENSED
 pragma solidity ^0.8.0;
 
-import "pyth-sdk-solidity/IPyth.sol";
-import "pyth-sdk-solidity/PythStructs.sol";
+import "@pythnetwork/pyth-sdk-solidity/IPyth.sol";
+import "@pythnetwork/pyth-sdk-solidity/PythStructs.sol";
+import "@pythnetwork/pyth-sdk-solidity/PythUtils.sol";
 import "openzeppelin-contracts/contracts/token/ERC20/ERC20.sol";
 
 // Example oracle AMM powered by Pyth price feeds.
@@ -17,7 +18,12 @@ import "openzeppelin-contracts/contracts/token/ERC20/ERC20.sol";
 // some quantity of both the base and quote token in order to function properly (using the ERC20 transfer function to
 // the contract's address).
 contract OracleSwap {
-    event Transfer(address from, address to, uint amountUsd, uint amountWei);
+    event Transfer(
+        address from,
+        address to,
+        uint256 amountUsd,
+        uint256 amountWei
+    );
 
     IPyth pyth;
 
@@ -53,10 +59,10 @@ contract OracleSwap {
     // See the frontend code for an example of how to retrieve this data and pass it to this function.
     function swap(
         bool isBuy,
-        uint size,
+        uint256 size,
         bytes[] calldata pythUpdateData
     ) external payable {
-        uint updateFee = pyth.getUpdateFee(pythUpdateData);
+        uint256 updateFee = pyth.getUpdateFee(pythUpdateData);
         pyth.updatePriceFeeds{value: updateFee}(pythUpdateData);
 
         PythStructs.Price memory currentBasePrice = pyth.getPrice(
@@ -69,8 +75,16 @@ contract OracleSwap {
         // Note: this code does all arithmetic with 18 decimal points. This approach should be fine for most
         // price feeds, which typically have ~8 decimals. You can check the exponent on the price feed to ensure
         // this doesn't lose precision.
-        uint256 basePrice = convertToUint(currentBasePrice, 18);
-        uint256 quotePrice = convertToUint(currentQuotePrice, 18);
+        uint256 basePrice = PythUtils.convertToUint(
+            currentBasePrice.price,
+            currentBasePrice.expo,
+            18
+        );
+        uint256 quotePrice = PythUtils.convertToUint(
+            currentQuotePrice.price,
+            currentQuotePrice.expo,
+            18
+        );
 
         // This computation loses precision. The infinite-precision result is between [quoteSize, quoteSize + 1]
         // We need to round this result in favor of the contract.
@@ -90,28 +104,6 @@ contract OracleSwap {
         }
     }
 
-    // TODO: we should probably move something like this into the solidity sdk
-    function convertToUint(
-        PythStructs.Price memory price,
-        uint8 targetDecimals
-    ) private pure returns (uint256) {
-        if (price.price < 0 || price.expo > 0 || price.expo < -255) {
-            revert();
-        }
-
-        uint8 priceDecimals = uint8(uint32(-1 * price.expo));
-
-        if (targetDecimals >= priceDecimals) {
-            return
-                uint(uint64(price.price)) *
-                10 ** uint32(targetDecimals - priceDecimals);
-        } else {
-            return
-                uint(uint64(price.price)) /
-                10 ** uint32(priceDecimals - targetDecimals);
-        }
-    }
-
     // Get the number of base tokens in the pool
     function baseBalance() public view returns (uint256) {
         return baseToken.balanceOf(address(this));

target_chains/ethereum/examples/oracle_swap/contract/src/OracleSwap.sol

@@ -3,7 +3,7 @@ pragma solidity ^0.8.0;
 
 import "forge-std/Test.sol";
 import "../src/OracleSwap.sol";
-import "pyth-sdk-solidity/MockPyth.sol";
+import "@pythnetwork/pyth-sdk-solidity/MockPyth.sol";
 import "openzeppelin-contracts/contracts/mocks/ERC20Mock.sol";
 
 contract OracleSwapTest is Test {
@@ -84,6 +84,7 @@ contract OracleSwapTest is Test {
             -5,
             basePrice * 100000,
             10 * 100000,
+            uint64(block.timestamp),
             uint64(block.timestamp)
         );
         updateData[1] = mockPyth.createPriceFeedUpdateData(
@@ -93,6 +94,7 @@ contract OracleSwapTest is Test {
             -5,
             quotePrice * 100000,
             10 * 100000,
+            uint64(block.timestamp),
             uint64(block.timestamp)
         );