fix(balances): show "--" for the total when no token has a price

extension/src/popup/components/account/AccountSheet/hooks/useGetWalletsData.tsx

@@ -131,7 +131,7 @@ function useGetWalletsData() {
             networkDetails,
             useCache: true,
           });
-          const totalPriceUsd = getTotalUsd(
+          const { totalUsd, hasPrices } = getTotalUsd(
             prices.tokenPrices || {},
             visibleBalances,
           );
@@ -140,8 +140,8 @@ function useGetWalletsData() {
               hasError: false,
               hasPriceFeed: isMainnetNetwork,
               isFunded: !!balances.isFunded,
-              tokenPrices: prices.tokenPrices,
-              totalUsd: totalPriceUsd,
+              hasPrices,
+              totalUsd,
             }),
           };
         } catch (error) {

extension/src/popup/helpers/__tests__/balance.test.js

@@ -303,7 +303,7 @@ describe("SEP-41 balances are valued in whole units", () => {
   });
 
   it("sums the scaled value into the total", () => {
-    const total = getTotalUsd(prices, [SOLVBTC, USDC]);
+    const { totalUsd: total } = getTotalUsd(prices, [SOLVBTC, USDC]);
     expect(total.toNumber()).toBeCloseTo(100.18522526, 6);
   });
 });

extension/src/popup/helpers/__tests__/getTotalUsdLabel.test.ts

@@ -1,18 +1,15 @@
 import BigNumber from "bignumber.js";
 
-import { getTotalUsdLabel } from "popup/helpers/balance";
+import { AssetType } from "@shared/api/types/account-balance";
 import { ApiTokenPrices } from "@shared/api/types";
-
-const PRICES = {
-  "XLM:native": { currentPrice: "0.5", percentagePriceChange24h: null },
-} as unknown as ApiTokenPrices;
+import { getTotalUsd, getTotalUsdLabel } from "popup/helpers/balance";
 
 const label = (overrides: Partial<Parameters<typeof getTotalUsdLabel>[0]>) =>
   getTotalUsdLabel({
     hasError: false,
     hasPriceFeed: true,
     isFunded: true,
-    tokenPrices: PRICES,
+    hasPrices: true,
     totalUsd: new BigNumber("1149.239"),
     ...overrides,
   });
@@ -36,14 +33,64 @@ describe("getTotalUsdLabel", () => {
     expect(label({ hasError: true })).toBe("--");
   });
 
-  it("returns the placeholder when a funded account prices nothing", () => {
-    expect(label({ tokenPrices: null })).toBe("--");
-    expect(label({ tokenPrices: undefined })).toBe("--");
-    expect(label({ tokenPrices: {} as ApiTokenPrices })).toBe("--");
+  it("returns the placeholder when no held balance has a price", () => {
+    expect(label({ hasPrices: false })).toBe("--");
+    expect(label({ hasPrices: undefined })).toBe("--");
   });
 
   // A real zero on a priced network still reads as a total, not a gap.
   it("keeps a genuine zero total distinct from the placeholder", () => {
     expect(label({ totalUsd: new BigNumber(0) })).toBe("$0.00");
   });
 });
+
+const USDC_ISSUER = "GA5ZSEJYB37JRC5AVCIA5MOP4RHTM335X2KGX3IHOJAPP5RE34K4KZVN";
+const USDC = `USDC:${USDC_ISSUER}`;
+// A token the account does not hold, such as a swap destination.
+const EURC = `EURC:${USDC_ISSUER}`;
+
+const HELD = [
+  { token: { type: "native", code: "XLM" }, total: new BigNumber("100") },
+  {
+    token: {
+      type: "credit_alphanum4",
+      code: "USDC",
+      issuer: { key: USDC_ISSUER },
+    },
+    total: new BigNumber("40"),
+  },
+] as unknown as AssetType[];
+
+const usd = (prices: ApiTokenPrices) => {
+  const { totalUsd, hasPrices } = getTotalUsd(prices, HELD);
+  return { totalUsd: totalUsd.toString(), hasPrices };
+};
+
+describe("getTotalUsd", () => {
+  it("sums only the priced held balances", () => {
+    expect(usd({ native: { currentPrice: "0.5" }, [USDC]: null })).toEqual({
+      totalUsd: "50",
+      hasPrices: true,
+    });
+  });
+
+  // The backend can return a key per token with no price behind any of them.
+  it("reports no prices when every price is null", () => {
+    expect(usd({ native: null, [USDC]: null })).toEqual({
+      totalUsd: "0",
+      hasPrices: false,
+    });
+  });
+
+  it("reports no prices for an empty price map", () => {
+    expect(usd({})).toEqual({ totalUsd: "0", hasPrices: false });
+  });
+
+  // The price cache can keep tokens the account does not hold. They add
+  // nothing to the total and do not count as a price.
+  it("ignores a price for a token the account does not hold", () => {
+    expect(
+      usd({ native: null, [USDC]: null, [EURC]: { currentPrice: "1.1" } }),
+    ).toEqual({ totalUsd: "0", hasPrices: false });
+  });
+});

extension/src/popup/helpers/balance.ts

@@ -275,21 +275,40 @@ export const sortBalancesByValue = (
     .map((x) => x.b);
 };
 
-export const getTotalUsd = (prices: ApiTokenPrices, balances: AssetType[]) => {
-  return Object.keys(prices).reduce((prev, curr) => {
-    const asset = getAssetFromCanonical(curr);
-    const priceBalance = getBalanceByAsset(asset, balances);
-    if (!priceBalance) {
-      return prev;
-    }
-    const currentAssetBalance = getTotalInWholeUnits(priceBalance);
-    const currentPrice = prices[curr] ? prices[curr].currentPrice : "0";
-    const currentUsdBalance = new BigNumber(currentPrice).multipliedBy(
-      currentAssetBalance,
-    );
-    return currentUsdBalance.plus(prev);
-  }, new BigNumber(0));
-};
+/**
+ * Sums the USD value of the held balances, and reports whether any held
+ * balance has a price. One lookup gives both, so the label and the total
+ * always count the same prices.
+ *
+ * The price map can hold tokens the account does not hold, such as a swap
+ * destination in the price cache. Those do not count. A token with a null or
+ * empty price adds nothing.
+ */
+export const getTotalUsd = (prices: ApiTokenPrices, balances: AssetType[]) =>
+  Object.keys(prices).reduce(
+    (acc, canonical) => {
+      const currentPrice = prices[canonical]?.currentPrice;
+      if (!currentPrice) {
+        return acc;
+      }
+      const balance = getBalanceByAsset(
+        getAssetFromCanonical(canonical),
+        balances,
+      );
+      if (!balance) {
+        return acc;
+      }
+      return {
+        totalUsd: acc.totalUsd.plus(
+          new BigNumber(currentPrice).multipliedBy(
+            getTotalInWholeUnits(balance),
+          ),
+        ),
+        hasPrices: true,
+      };
+    },
+    { totalUsd: new BigNumber(0), hasPrices: false },
+  );
 
 /**
  * Picks what to show for an account's total USD value.
@@ -301,15 +320,19 @@ export const getTotalUsdLabel = ({
   hasError,
   hasPriceFeed,
   isFunded,
-  tokenPrices,
+  hasPrices = false,
   totalUsd,
 }: {
   /** Account data failed to load. */
   hasError: boolean;
   /** Whether the network prices tokens at all. */
   hasPriceFeed: boolean;
   isFunded: boolean;
-  tokenPrices?: ApiTokenPrices | null;
+  /**
+   * At least one held balance has a price. See {@link getTotalUsd}. Omit
+   * where no prices were fetched.
+   */
+  hasPrices?: boolean;
   /** Omit where no total was computed; the branches that ignore it win. */
   totalUsd?: BigNumber;
 }) => {
@@ -326,8 +349,9 @@ export const getTotalUsdLabel = ({
   }
 
   // A funded account on a network that prices tokens, yet nothing priced —
-  // the total exists but could not be read.
-  if (!tokenPrices || Object.keys(tokenPrices).length === 0) {
+  // the total exists but could not be read. One priced token is enough: the
+  // total is then a partial sum.
+  if (!hasPrices) {
     return NO_FIAT_VALUE;
   }
 

extension/src/popup/views/Account/index.tsx

@@ -211,15 +211,18 @@ export const Account = () => {
   // was dismissed.
   const reloadBalances = () => refreshBalances();
 
-  const totalBalanceUsd = getTotalUsd(tokenPrices ?? {}, balances);
+  const { totalUsd: totalBalanceUsd, hasPrices } = getTotalUsd(
+    tokenPrices ?? {},
+    balances,
+  );
   // The hero is never hidden; see getTotalUsdLabel for which of a total, a
   // zero or the placeholder it shows. The network comes from Redux because
   // `resolvedData` is null once the fetch has failed.
   const roundedTotalBalanceUsd = getTotalUsdLabel({
     hasError,
     hasPriceFeed: isMainnet(networkDetails),
     isFunded,
-    tokenPrices,
+    hasPrices,
     totalUsd: totalBalanceUsd,
   });