fix: the ETH line reads unknown at an address no refresh has read (closes #736)

An address's ETH balance is now null until a refresh has read it. That covers
a new address, a new wallet, addresses a wallet scan finds, and every address
after a network switch.

Its line reads `quantity unknown`, Home's balance `unknown (ETH)`, and Send
`Current balance: unknown (ETH)`. Max says the balance is unknown. Send is no
longer refused as zero. The address has no total, and DeleteAddress warns that
it may hold a balance.

A refresh also deletes `balanceNotFetched` only when it read every address in
the stored record.

Model: opus-5-5

README.md

@@ -1025,7 +1025,8 @@ removing the address only stops the wallet tracking it. It explains the way
 back: delete the whole wallet in Settings and import its backup again. The scan
 after an import finds only addresses with on-chain activity. When the address
 holds anything, the screen lists the holdings and the USD total under a warning.
-An ETH balance that no refresh has read counts as holding something.
+An ETH balance that no refresh has read counts as holding something. The warning
+then reads "This address may hold a balance."
 
 "Remove Address" removes the address and its site permissions. It returns to
 Home with the flash message "Address removed." The wallet's `nextIndex` is not

src/popup/views/deleteAddress.js

@@ -87,15 +87,22 @@ function recoveryPathText(wallet) {
 // when every holding here is one with no price, since "$0.00" directly under
 // "This address holds a balance." is a contradiction. A token holding below
 // 0.000001 does not count, as the lines below leave it out.
+//
+// While no refresh has read the ETH balance the address may be empty, so the
+// sentence says "may hold".
 function balanceWarningHtml(addr) {
     if (!addressHoldsFunds(addr)) return " ";
     const line = formatAddressTotal(getAddressValue(addr));
     const total = line
         ? `<div class="text-xs text-muted mt-1">${escapeHtml(line)}</div>`
         : "";
+    const sentence =
+        addr.balance == null
+            ? "This address may hold a balance."
+            : "This address holds a balance.";
     return (
-        `<p class="mb-1">This address holds a balance. Removing it does not ` +
-        `move or spend anything; the balance stays at the address.</p>` +
+        `<p class="mb-1">${sentence} Removing it does not move or spend ` +
+        `anything; the balance stays at the address.</p>` +
         balanceLinesForAddress(addr, state.trackedTokens, false) +
         total
     );

src/popup/views/helpers.js

@@ -494,9 +494,9 @@ function balanceLinesForAddress(addr, trackedTokens, showZero) {
 // about holdings must ask this, not the rendered figure.
 function addressHoldsFunds(addr) {
     if (!addr) return false;
-    // A null ETH balance is one no refresh has read, so the address may hold
+    // A null or absent ETH balance reads as unknown, so the address may hold
     // funds. Warning about funds must err towards warning.
-    if (addr.balance === null) return true;
+    if (addr.balance == null) return true;
     if (parseFloat(addr.balance) > 0) return true;
     for (const t of addr.tokenBalances || []) {
         if (isBelowOneMillionth(t.balance)) continue;

src/shared/prices.js

@@ -146,8 +146,8 @@ function formatUsd(amount) {
 // 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, before the first fetch, or
-//            an ETH balance no refresh has read.
+//            no total can be stated — testnet, before the first fetch, or an
+//            ETH balance no refresh has read.
 //   partial: the address also holds a token with no price, so usd is a floor
 //            and not the total.
 //

tests/deleteAddress.test.js

@@ -117,9 +117,13 @@ describe("whether an address holds anything", () => {
         expect(addressHoldsFunds(ZERO_TOKEN)).toBe(false);
     });
 
-    test("a missing address or missing fields do not", () => {
+    test("a missing address does not", () => {
         expect(addressHoldsFunds(undefined)).toBe(false);
-        expect(addressHoldsFunds({ address: "0x1" })).toBe(false);
+    });
+
+    // It reads as unknown, as a null balance does.
+    test("an address with no ETH balance field counts", () => {
+        expect(addressHoldsFunds({ address: "0x1" })).toBe(true);
     });
 });
 
@@ -146,16 +150,23 @@ describe("the balance warning on the removal confirmation", () => {
         expect(html).toContain("<span>0.0000</span>");
     });
 
-    // The sentence must not assert an amount, because any amount it could
-    // assert has been rounded: "This address holds 0.0000 ETH." is what the
-    // rounded form produces for an address that holds real money.
     test("an ETH balance no refresh has read is warned about, and reads as unknown", () => {
         const html = balanceWarningHtml(NOT_READ);
-        expect(html).toContain("This address holds a balance");
+        expect(html).toContain("This address may hold a balance.");
+        expect(html).not.toContain("This address holds a balance.");
         expect(html).toContain("quantity unknown");
         expect(html).not.toContain("0.0000");
     });
 
+    test("an address with no ETH balance field reads the same", () => {
+        expect(balanceWarningHtml({ address: "0x1" })).toContain(
+            "This address may hold a balance.",
+        );
+    });
+
+    // The sentence must not assert an amount, because any amount it could
+    // assert has been rounded: "This address holds 0.0000 ETH." is what the
+    // rounded form produces for an address that holds real money.
     test("the warning sentence asserts no rounded amount", () => {
         for (const addr of [DUST, ETH_ONLY, TOKEN_ONLY]) {
             expect(balanceWarningHtml(addr)).not.toMatch(