feat: Introduce and use TickPriceHelper.TickFromVolumes

src/liquidityProvider.ts

@@ -14,8 +14,6 @@ import { OfferLogic } from ".";
 import PrettyPrint, { prettyPrintFilter } from "./util/prettyPrint";
 import Trade from "./util/trade";
 import TickPriceHelper from "./util/tickPriceHelper";
-import { TickLib } from "./util/coreCalculations/TickLib";
-import { BigNumber } from "ethers/lib/ethers";
 
 // eslint-disable-next-line @typescript-eslint/no-namespace
 namespace LiquidityProvider {
@@ -219,36 +217,25 @@ class LiquidityProvider {
   } {
     const tickPriceHelper = new TickPriceHelper(p.ba, market);
     let tick: ethers.BigNumber, gives: Big, price: Big;
-    // deduce price from tick & gives, or deduce tick & gives from volume & price
     if ("tick" in p) {
+      // deduce price from tick & gives
       tick = ethers.BigNumber.from(p.tick);
       price = tickPriceHelper.priceFromTick(tick);
       gives = Big(p.gives);
     } else if ("price" in p) {
+      // deduce tick & gives from volume & price
       price = Big(p.price);
       tick = tickPriceHelper.tickFromPrice(price);
-      if (p.ba === "asks") {
-        gives = Big(p.volume);
-      } else {
+      if (p.ba === "bids") {
         gives = Big(p.volume).mul(price);
+      } else {
+        gives = Big(p.volume);
       }
     } else {
+      // deduce tick and price from wants & gives
       gives = Big(p.gives);
       const wants = Big(p.wants);
-
-      tick = TickLib.tickFromVolumes(
-        BigNumber.from(
-          p.ba === "asks"
-            ? wants.mul(Big(10).pow(market.quote.decimals)).toFixed()
-            : wants.mul(Big(10).pow(market.base.decimals)).toFixed(),
-        ),
-        BigNumber.from(
-          p.ba === "asks"
-            ? gives.mul(Big(10).pow(market.base.decimals)).toFixed()
-            : gives.mul(Big(10).pow(market.quote.decimals)).toFixed(),
-        ),
-      );
-
+      tick = tickPriceHelper.tickFromVolumes(wants, gives);
       if (p.ba === "bids") {
         price = Big(gives).div(wants);
       } else {

src/util/tickPriceHelper.ts

@@ -137,6 +137,29 @@ class TickPriceHelper {
         : this.market.base.decimals,
     );
   }
+
+  /**
+   * Calculates the tick from inbound and outbound volumes.
+   * @param inboundVolume inbound amount to calculate the tick for
+   * @param outboundVolume outbound amount to calculate the tick for
+   * @returns raw offer list tick for volumes
+   */
+  tickFromVolumes(inboundVolume: Bigish, outboundVolume: Bigish): BigNumber {
+    const rawInbound = UnitCalculations.toUnits(
+      inboundVolume,
+      this.ba === "bids"
+        ? this.market.base.decimals
+        : this.market.quote.decimals,
+    );
+    const rawOutbound = UnitCalculations.toUnits(
+      outboundVolume,
+      this.ba === "bids"
+        ? this.market.quote.decimals
+        : this.market.base.decimals,
+    );
+    const tick = TickLib.tickFromVolumes(rawInbound, rawOutbound);
+    return tick;
+  }
 }
 
 export default TickPriceHelper;

test/unit/tickPriceHelper.unit.test.ts

@@ -150,6 +150,34 @@ describe(`${TickPriceHelper.prototype.constructor.name} unit tests suite`, () =>
     });
   });
 
+  describe(TickPriceHelper.prototype.tickFromVolumes.name, () => {
+    it("returns tick=0 for inboundVolume=1, outboundVolume=1 with base decimals: 6, quote decimals: 6 (bids semibook)", () => {
+      // Arrange
+      const tickPriceHelper = new TickPriceHelper("bids", {
+        base: { decimals: 6 },
+        quote: { decimals: 6 },
+      });
+
+      // Act
+      const result = tickPriceHelper.tickFromVolumes(1, 1);
+      // Assert
+      assert.equal(0, result.toNumber());
+    });
+
+    it("returns tick=0 for inboundVolume=1, outboundVolume=1 with base decimals: 6, quote decimals: 6 (asks semibook)", () => {
+      // Arrange
+      const tickPriceHelper = new TickPriceHelper("asks", {
+        base: { decimals: 6 },
+        quote: { decimals: 6 },
+      });
+
+      // Act
+      const result = tickPriceHelper.tickFromVolumes(1, 1);
+      // Assert
+      assert.equal(0, result.toNumber());
+    });
+  });
+
   describe(TickPriceHelper.prototype.tickFromPrice.name, () => {
     priceAndTickPairs.forEach(({ args, tick, price }) => {
       it(`returns tick=${tick} for price ${price} with base decimals: ${args.market.base.decimals}, quote decimals: ${args.market.quote.decimals} (${args.ba} semibook)) `, () => {
@@ -235,8 +263,35 @@ describe(`${TickPriceHelper.prototype.constructor.name} unit tests suite`, () =>
       .tickFromPrice(displayPrice)
       .toNumber();
 
-    assert.equal(rawAskTick, calcAskTick);
-    assert.equal(rawBidTick, calcBidTick);
+    // relate tickFromPrice to tickFromVolumes
+    const calcAskTickFromVolumes = askTickPriceHelper
+      .tickFromVolumes(displayAskInbound, displayAskOutbound)
+      .toNumber();
+    const calcBidTickFromVolumes = bidTickPriceHelper
+      .tickFromVolumes(displayBidInbound, displayBidOutbound)
+      .toNumber();
+
+    assert.equal(
+      rawAskTick,
+      calcAskTickFromVolumes,
+      "rawAskTick not equal to ask tick calculated from volumes",
+    );
+    assert.equal(
+      rawBidTick,
+      calcBidTickFromVolumes,
+      "rawBidTick not equal to bid tick calculated from volumes",
+    );
+
+    assert.equal(
+      rawAskTick,
+      calcAskTick,
+      "rawAskTick not equal to ask tick calculated from price",
+    );
+    assert.equal(
+      rawBidTick,
+      calcBidTick,
+      "rawBidTick not equal to bid tick calculated from price",
+    );
 
     const calcAskPrice = askTickPriceHelper.priceFromTick(rawAskTick);
     const calcBidPrice = bidTickPriceHelper.priceFromTick(rawBidTick);