Reading chainweb configuration from json

Author: jermaine150

chainweb.config.json

@@ -1,11 +1,11 @@
 {
     "anvil": {
-        "chains": 5,
+        "numberOfChains": 5,
         "chainwebChainIdOffset": 20,
         "chainIdOffset": 62600
     },
     "sandbox": {
-        "chains": 5,
+        "numberOfChains": 5,
         "chainwebChainIdOffset": 20,
         "chainIdOffset": 1789,
         "extenalHostUrl": "http://localhost:1848/chainweb/0.0/evm-development"

foundry.toml

@@ -5,5 +5,6 @@ test = "src/example/test"
 out = "src/example/out"
 broadcast = "src/example/broadcast"
 libs = ["lib"]
+fs_permissions = [{ access = "read", path = "./chainweb.config.json" }]
 
 # See more config options https://github.com/foundry-rs/foundry/blob/master/crates/config/README.md#all-options

src/Chainweb.sol

@@ -108,35 +108,78 @@ struct ChainwebConfig {
     uint256 numberOfChains;
     uint256 chainIdOffset;
     uint256 chainwebChainIdOffset;
+    string extenalHostUrl;
 }
 
-contract ChainwebTest is Test {
+contract ChainwebConfigReader is CommonBase {
+    function readOptionalJsonUint(string memory json, string memory key, uint256 defaultValue) internal returns (uint256) {
+        try vm.parseJsonUint(json, key) returns (uint256 value) {
+            return value;
+        } catch {
+            return defaultValue;
+        }
+    }
+
+    function readOptionalJsonString(string memory json, string memory key, string memory defaultValue) internal returns (string memory) {
+        try vm.parseJsonString(json, key) returns (string memory value) {
+            return value;
+        } catch {
+            return defaultValue;
+        }
+    }
+
+    function readChainwebConfig(string memory environment) internal returns (ChainwebConfig memory) {
+        string memory root = vm.projectRoot();
+        string memory path = string(abi.encodePacked(root, "/chainweb.config.json"));
+        string memory json = vm.readFile(path);
+
+        string memory envPath = string(abi.encodePacked(".", environment));
+
+        // Parse all fields from config
+        uint256 numberOfChains = readOptionalJsonUint(json, string(abi.encodePacked(envPath, ".numberOfChains")), 1);
+        uint256 chainIdOffset = readOptionalJsonUint(json, string(abi.encodePacked(envPath, ".chainIdOffset")), 31337);
+        uint256 chainwebChainIdOffset = readOptionalJsonUint(json, string(abi.encodePacked(envPath, ".chainwebChainIdOffset")), 0);
+        string memory extenalHostUrl = readOptionalJsonString(json, string(abi.encodePacked(envPath, ".extenalHostUrl")), "");
+
+        return ChainwebConfig({
+            numberOfChains: numberOfChains,
+            chainIdOffset: chainIdOffset,
+            chainwebChainIdOffset: chainwebChainIdOffset,
+            extenalHostUrl: extenalHostUrl
+        });
+    }
+}
+
+contract ChainwebTest is Test, ChainwebConfigReader {
     Chainweb public chainweb;
 
-    constructor(uint24 chainNumbers, uint24 chainwebChainIdOffset) {
-        // TODO: READ chainweb.json and initialize Chainweb
+    constructor(string memory environment) {
+        ChainwebConfig memory config = readChainwebConfig(environment);
         chainweb = new Chainweb(
-            chainNumbers,
+            uint24(config.numberOfChains),
             block.chainid,
-            chainwebChainIdOffset,
-            ""
+            uint24(config.chainwebChainIdOffset),
+            config.extenalHostUrl
         );
         chainweb.setupChainsForTest();
     }
 }
 
-contract ChainwebScript is Script {
+contract ChainwebScript is Script, ChainwebConfigReader {
     Chainweb public chainweb;
 
-    constructor(uint24 chainNumbers, uint24 chainwebChainIdOffset) {
+    constructor(string memory environment) {
+        ChainwebConfig memory config = readChainwebConfig(environment);
+
         string memory nodeUrl = vm.envExists("CHAINWEB_HOST")
             ? vm.envString("CHAINWEB_HOST")
-            : "";
+            : config.extenalHostUrl;
         console.log("Using node URL:", nodeUrl);
+
         chainweb = new Chainweb(
-            chainNumbers,
+            uint24(config.numberOfChains),
             block.chainid,
-            chainwebChainIdOffset,
+            uint24(config.chainwebChainIdOffset),
             nodeUrl
         );
         chainweb.setupChainsForScript();

src/example/script/Counter.s.sol

@@ -5,7 +5,7 @@ import {Script, console} from "forge-std/Script.sol";
 import {Counter} from "../src/Counter.sol";
 import {ChainwebScript} from "kadena-io/foundry-chainweb/Chainweb.sol";
 
-contract CounterScript is ChainwebScript(5, 20) {
+contract CounterScript is ChainwebScript("anvil") {
     Counter public counter;
 
     function run() public {

src/example/test/Counter.t.sol

@@ -5,25 +5,26 @@ import {Test, console} from "forge-std/Test.sol";
 import {Counter} from "../src/Counter.sol";
 import {ChainwebTest, ChainwebConfig} from "kadena-io/foundry-chainweb/Chainweb.sol";
 
-contract CounterTest is ChainwebTest(4, 0) {
+contract CounterTest is ChainwebTest("anvil") {
     function test_MultiChains() public {
-        chainweb.switchChain(0);
+        uint256[] memory chainIds = chainweb.getChainIds();
+        console.log("Available chain IDs:", chainIds.length);
+
+        chainweb.switchChain(chainIds[0]);
         Counter counter0 = new Counter();
         console.log("Running test on chain:", block.chainid);
         counter0.setNumber(10);
 
-        chainweb.switchChain(1);
+        chainweb.switchChain(chainIds[1]);
         Counter counter1 = new Counter();
         counter1.setNumber(11);
 
-        chainweb.switchChain(0);
+        chainweb.switchChain(chainIds[0]);
         counter0.increment();
-        assertEq(block.chainid, 31337);
         assertEq(counter0.number(), 11);
 
-        chainweb.switchChain(1);
+        chainweb.switchChain(chainIds[1]);
         counter1.increment();
-        assertEq(block.chainid, 31338);
         assertEq(counter1.number(), 12);
     }
 }