orderbuild fixes; tranche table work; ordershapes still broken

src/blockchain/uniswap.js

@@ -1,4 +1,4 @@
-import {ethers} from "ethers";
+import {ethers, FixedNumber} from "ethers";
 
 const UNISWAPV3_POOL_INIT_CODE_HASH = '0xe34f199b19b2b4f47f68442619d555527d244f78a3297ea89325f843f87b8b54'
 const uniswapV3Addresses = {
@@ -26,4 +26,14 @@ export function uniswapV3PoolAddress(chainId, tokenAddrA, tokenAddrB, fee) {
         return null
     }
     return ethers.getCreate2Address(factory, salt, UNISWAPV3_POOL_INIT_CODE_HASH)
+}
+
+
+export function uniswapV3AveragePrice(amountIn, amountOut, fee) {
+    if (amountIn === 0n || amountOut === 0n) return null
+    const fmtX18 = {decimals: 18, width: 256, signed: false};
+    let result = FixedNumber.fromValue(amountOut, 0, fmtX18)
+        .div(FixedNumber.fromValue(amountIn, 0, fmtX18)).toUnsafeFloat()
+    result /= (1 - fee / 1_000_000) // adjust for pool fee
+    return result
 }