feat: WASM Go - registering wasm module function in random js object

Author: ppedziwiatr

go/README.md

@@ -1,14 +1,8 @@
-# Go smartweave example contract
+# Go SmartWeave example contract
 
 ## Install go 1.17
 https://go.dev/doc/install
 
-## How to use (default Go compiler)
-- [Install easyjson](https://github.com/mailru/easyjson#install)
-- Run `easyjson -all easyjson/easyjson.go`
-- Build wasm contract file: `bash build.sh` (it should create `out` folder)
-- Run wasm contract simulation: `node run.js`
-
 ## How to use (tinygo compiler)
 - [Install tinygo](https://tinygo.org/getting-started/install/)
 - [Install easyjson](https://github.com/mailru/easyjson#install)

go/common/async.go

@@ -1,6 +1,7 @@
 package common
 
 import (
+	"math/rand"
 	"syscall/js"
 )
 
@@ -30,3 +31,13 @@ func Await(awaitable js.Value) ([]js.Value, []js.Value) {
 		return nil, err
 	}
 }
+
+var letters = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
+
+func RandSeq(n int) string {
+	b := make([]rune, n)
+	for i := range b {
+		b[i] = letters[rand.Intn(len(letters))]
+	}
+	return string(b)
+}

go/common/imports/wasm_module/imports.go

@@ -0,0 +1,13 @@
+package wasm_module
+
+import (
+	"syscall/js"
+)
+
+func RegisterWasmModule(wasmModuleId string) {
+	importModule().Call("registerWasmModule", wasmModuleId)
+}
+
+func importModule() js.Value {
+	return js.Global().Get("redstone").Get("go").Get("WasmModule")
+}

go/common/wasm.go

@@ -2,19 +2,30 @@ package common
 
 import (
 	"encoding/json"
+	"github.com/redstone-finance/redstone-contracts-wasm/go/common/imports/wasm_module"
 	"github.com/redstone-finance/redstone-contracts-wasm/go/common_types"
+	"math/rand"
 	"syscall/js"
+	"time"
 )
 
 func Run(contract common_types.SwContract) {
+	// generating random module id and registering it on host
+	// a workaround for potential wasm modules collision
+	rand.Seed(time.Now().UnixNano())
+	moduleId := RandSeq(20)
+	js.Global().Set(moduleId, make(map[string]interface{}))
+	wasmModule := js.Global().Get(moduleId)
 	// the Go way of defining WASM exports...
 	// standard "exports" from the wasm module do not work here...
 	// that's kinda ugly TBH
-	js.Global().Set("handle", handle(contract))
-	js.Global().Set("initState", initState(contract))
-	js.Global().Set("currentState", currentState(contract))
-	js.Global().Set("contractType", contractType())
-	js.Global().Set("lang", lang())
+	wasmModule.Set("handle", handle(contract))
+	wasmModule.Set("initState", initState(contract))
+	wasmModule.Set("currentState", currentState(contract))
+	wasmModule.Set("contractType", contractType())
+	wasmModule.Set("lang", lang())
+
+	wasm_module.RegisterWasmModule(moduleId)
 
 	// Prevent the function from returning, which is required in a wasm module
 	// i.e. "Error: Go program has already exited" is thrown otherwise on host

go/run-tiny.js

@@ -16,13 +16,15 @@ async function main() {
 
     let usedGas = 0;
 
-    console.log(go.importObject)
+    //console.log(go.importObject)
     go.importObject.metering = {
         usegas: function (value) {
             usedGas += value;
         }
     }
 
+    let moduleExports = {};
+
     global.redstone.go = {
         console: {
             log: function (...args) {
@@ -74,9 +76,17 @@ async function main() {
                     }
                 }
             },
+        },
+        WasmModule: {
+            registerWasmModule: function(moduleId) {
+                moduleExports = global[moduleId];
+                delete moduleId;
+                console.log(moduleExports);
+            }
         }
     }
 
+
     const wasmBinary = fs.readFileSync('./.out/contract_tiny.wasm');
     /*const meteredWasmBinary = metering.meterWASM(wasmBinary, {
         meterType: "i32",
@@ -85,13 +95,14 @@ async function main() {
     const module = await WebAssembly.instantiate(wasmBinary, go.importObject);
 
     const wasm = module.instance;
-    go.run(wasm);
 
     console.log(wasm.exports);
-
-    console.log('\nlang():', lang());
-    console.log('\ncontractType():', contractType());
-    console.log('\ninitState():', initState(JSON.stringify(
+    console.log('calling go run');
+    go.run(wasm);
+    console.log('go run called');
+    console.log('\nlang():', moduleExports.lang());
+    console.log('\ncontractType():', moduleExports.contractType());
+    console.log('\ninitState():', moduleExports.initState(JSON.stringify(
         {
             "ticker": "EXAMPLE_PST_TOKEN",
             "owner": "uhE-QeYS8i4pmUtnxQyHD7dzXFNaJ9oMK-IM-QPNY6M",
@@ -102,13 +113,13 @@ async function main() {
             }
         }
     )));
-    console.log('\ncurrentState()', JSON.parse(currentState()));
+    console.log('\ncurrentState()', JSON.parse(moduleExports.currentState()));
 
     console.log("\nCalling async handle - transfer");
 
     usedGas = 0;
 
-    const resultTransfer = await handle(JSON.stringify({
+    const resultTransfer = await moduleExports.handle(JSON.stringify({
         function: 'transfer',
         target: 'uhE-QeYS8i4pmUtnxQyHD7dzXFNaJ9oMK-IM-QPNY6M',
         qty: 555555
@@ -117,18 +128,18 @@ async function main() {
     console.log('Result from transfer:', resultTransfer);
     console.log('Gas used', usedGas);
 
-    console.log('\ncurrentState()', JSON.parse(currentState()));
+    console.log('\ncurrentState()', JSON.parse(moduleExports.currentState()));
 
     console.log("\nCalling async handle - balance");
-    const resultBalance = await handle(JSON.stringify({
+    const resultBalance = await moduleExports.handle(JSON.stringify({
         function: 'balance',
         target: 'uhE-QeYS8i4pmUtnxQyHD7dzXFNaJ9oMK-IM-QPNY6M',
     }));
     // result should be target balance value - "view" functions return value
     console.log('Result from balance:', resultBalance);
 
     console.log("\nCalling async handle - foreignCall");
-    const resultFc = await handle(JSON.stringify({
+    const resultFc = await moduleExports.handle(JSON.stringify({
         function: 'foreignCall',
         target: 'some-random-contract',
     }));
@@ -137,7 +148,7 @@ async function main() {
 
     console.log("\n\nChecking exception handling (should throw here)");
     try {
-        await handle(JSON.stringify({
+        await moduleExports.handle(JSON.stringify({
             function: 'someRandomFunction',
         }));
     } catch (e) {