Support Sui Gas Fee Calc (#1267)

* sui fee calc

* fix linter

* fix lint

Author: stackman27

internal/libs/mathslib/calc.go

@@ -88,6 +88,20 @@ func CalculateUsdPerUnitGas(
 		tmp := new(big.Int).Mul(sourceGasPrice, usdPerFeeCoin)
 		return new(big.Int).Div(tmp, big.NewInt(1e18)), nil
 
+	case chainsel.FamilySui:
+		// In Sui, sourceGasPrice is denoted in mist/gas unit or 1e-9 SUI/gas.
+		// SUI has 9 decimals, usdPerFeeCoin represents 1e18 USD * 1e9 = 1e27 USD per full SUI.
+
+		// usdPerFeeCoin is 1e18 USD per 1e18 smallest token unit by convention.
+		// When the token has 9 decimals (SUI), 1e18 smallest token units = 1e9 whole tokens.
+		// Therefore, usdPerFeeCoin represents 1e18 USD * 1e9 = 1e27 USD per SUI.
+
+		//   = (mist / gas) * (1e18 USD * 1e9 / mist) / 1e18
+		//   = (sourceGasPrice * usdPerFeeCoin) / 1e18
+
+		tmp := new(big.Int).Mul(sourceGasPrice, usdPerFeeCoin)
+		return new(big.Int).Div(tmp, big.NewInt(1e18)), nil
+
 	case chainsel.FamilyTon:
 		// In TON, sourceGasPrice is denoted in nanoton/gas or 1e-9 TON/gas.
 		// TON has 9 decimals, usdPerFeeCoin represents 1e18 USD * 1e9 / nanoton.

internal/libs/mathslib/calc_test.go

@@ -17,6 +17,7 @@ var (
 	SolChainSelector = ccipocr3.ChainSelector(sel.SOLANA_DEVNET.Selector)
 	EvmChainSelector = ccipocr3.ChainSelector(sel.ETHEREUM_TESTNET_SEPOLIA.Selector)
 	AptChainSelector = ccipocr3.ChainSelector(sel.APTOS_TESTNET.Selector)
+	SuiChainSelector = ccipocr3.ChainSelector(sel.SUI_TESTNET.Selector)
 	TonChainSelector = ccipocr3.ChainSelector(sel.TON_TESTNET.Selector)
 )
 
@@ -198,6 +199,28 @@ func TestCalculateUsdPerUnitGas(t *testing.T) {
 			chainSelector:  AptChainSelector,
 			exp:            big.NewInt(0 * 1 * 1e10), // gasprice * USD per APT * (USD / APT)
 		},
+		{
+			name:           "sui high fee case",
+			sourceGasPrice: big.NewInt(100000),
+			//  usdPerFeeCoin = $4 * 1e9 * 1e18 = 4e27
+			usdPerFeeCoin: new(big.Int).Mul(big.NewInt(4), new(big.Int).Mul(big.NewInt(1e9), big.NewInt(1e18))),
+			chainSelector: SuiChainSelector,
+			exp:           big.NewInt(100000 * 4e9),
+		},
+		{
+			name:           "sui low fee case",
+			sourceGasPrice: big.NewInt(100),
+			usdPerFeeCoin:  new(big.Int).Mul(big.NewInt(4), new(big.Int).Mul(big.NewInt(1e9), big.NewInt(1e18))),
+			chainSelector:  SuiChainSelector,
+			exp:            big.NewInt(100 * 4e9),
+		},
+		{
+			name:           "sui 0 fee case",
+			sourceGasPrice: big.NewInt(0),
+			usdPerFeeCoin:  new(big.Int).Mul(big.NewInt(4), new(big.Int).Mul(big.NewInt(1e9), big.NewInt(1e18))),
+			chainSelector:  SuiChainSelector,
+			exp:            big.NewInt(0),
+		},
 		{
 			name:           "ton base case",
 			sourceGasPrice: big.NewInt(400),