fix: an address holding only unpriced tokens is no longer totalled at $0.00 (closes #261)

src/shared/prices.js

@@ -55,42 +55,77 @@ function formatUsd(amount) {
     );
 }
 
-function getAddressValueUsd(addr) {
+// What an address is worth, as { usd, partial }.
+//
+// Prices are fetched for the top 25 tokens only, so an address can hold real
+// assets this code has no price for. Adding up the priced ones and calling the
+// result the total states a number the holdings do not support: an address
+// holding nothing but unpriced tokens comes out at $0.00, which tells the user
+// their address is worth nothing when it may hold a great deal. Worth zero and
+// worth an unknown amount are separate facts and get separate fields, the same
+// way an absent holders_count is not a count of zero.
+//
+//   usd:     the value of the holdings a price is known for, or null when
+//            nothing is knowable at all — testnet, or before the first fetch.
+//   partial: the address also holds a token with no price, so usd is a floor
+//            and not the total.
+//
+// Render it through formatAddressTotal() rather than reading usd alone.
+function getAddressValue(addr) {
     const { currentNetwork } = require("./state");
-    if (currentNetwork().isTestnet) return null;
-    if (!prices.ETH) return null;
-    let total = 0;
-    const ethBal = parseFloat(addr.balance || "0");
-    total += ethBal * prices.ETH;
+    if (currentNetwork().isTestnet) return { usd: null, partial: false };
+    if (!prices.ETH) return { usd: null, partial: false };
+    let usd = parseFloat(addr.balance || "0") * prices.ETH;
+    let partial = false;
     for (const token of addr.tokenBalances || []) {
         const tokenBal = parseFloat(token.balance || "0");
-        if (tokenBal > 0 && prices[token.symbol]) {
-            total += tokenBal * prices[token.symbol];
+        // A balance of zero is not a holding: it can neither add to the total
+        // nor make it incomplete.
+        if (!(tokenBal > 0)) continue;
+        if (prices[token.symbol]) {
+            usd += tokenBal * prices[token.symbol];
+        } else {
+            partial = true;
         }
     }
-    return total;
+    return { usd, partial };
 }
 
-function getWalletValueUsd(wallet) {
-    const { currentNetwork } = require("./state");
-    if (currentNetwork().isTestnet) return null;
-    if (!prices.ETH) return null;
-    let total = 0;
-    for (const addr of wallet.addresses) {
-        total += getAddressValueUsd(addr);
-    }
-    return total;
+// The same pair for a whole wallet, and for every wallet at once. One
+// unpriced holding anywhere makes the sum a floor, so partial carries up.
+function getWalletValue(wallet) {
+    return sumValues(wallet.addresses.map(getAddressValue));
 }
 
-function getTotalValueUsd(wallets) {
-    const { currentNetwork } = require("./state");
-    if (currentNetwork().isTestnet) return null;
-    if (!prices.ETH) return null;
-    let total = 0;
-    for (const wallet of wallets) {
-        total += getWalletValueUsd(wallet);
+function getTotalValue(wallets) {
+    return sumValues(wallets.map(getWalletValue));
+}
+
+function sumValues(values) {
+    let usd = null;
+    let partial = false;
+    for (const value of values) {
+        if (value.usd === null) continue;
+        usd = (usd === null ? 0 : usd) + value.usd;
+        partial = partial || value.partial;
     }
-    return total;
+    return { usd, partial };
+}
+
+// The one rendering of an address total, so no screen says it differently.
+//
+// A partial total is shown and named as partial: the figure is the ETH and
+// priced tokens the user does hold, which is worth having, and suppressing it
+// would throw away a number that is correct as far as it goes. What is never
+// shown is a figure covering no holdings at all — the $0.00 sum of an empty
+// set beside a list of tokens is the bug this replaces.
+function formatAddressTotal(value) {
+    if (!value || value.usd === null) return "";
+    if (!value.partial) return "Total: " + formatUsd(value.usd);
+    if (value.usd > 0) {
+        return "Total: " + formatUsd(value.usd) + " plus unpriced tokens";
+    }
+    return "Total: unpriced tokens only";
 }
 
 module.exports = {
@@ -99,7 +134,8 @@ module.exports = {
     clearPrices,
     getPrice,
     formatUsd,
-    getAddressValueUsd,
-    getWalletValueUsd,
-    getTotalValueUsd,
+    formatAddressTotal,
+    getAddressValue,
+    getWalletValue,
+    getTotalValue,
 };