fix: two pages switching networks no longer lose tracked tokens (closes #701)

A page that had not yet taken another page's network switch could lose
tracked tokens in two ways.

- Its save of an added or removed token wrote its own network's list as
  the new network's list. saveState() now keeps the stored list when the
  merged record names a network other than this page's.
- Its own switch in Settings wrote its old lists of tracked tokens per
  network over the stored ones. onChainSwitch() now first takes the
  stored switch with takeStoredNetwork(), as followStoredSettings() does,
  and then switches from there.

Model: opus-5-5

src/shared/chainSwitch.js

@@ -61,20 +61,31 @@ function clearPopupCaches() {
 // (https://git.eeqj.de/sneak/AutistMask/issues/653,
 // https://git.eeqj.de/sneak/AutistMask/issues/692).
 //
+// When the stored record is on another network, a switch saved elsewhere has
+// not reached this page yet. This page first takes that switch with
+// takeStoredNetwork() (state.js), as followStoredSettings() does. The switch to
+// `newNetworkId` is then made from the stored record's network. So every
+// network's list of tracked tokens in the stored record is kept
+// (https://git.eeqj.de/sneak/AutistMask/issues/701). When the stored record is
+// already on `newNetworkId`, the switch made from there only resets the
+// balances and caches.
+//
 // Before the switch, `state` takes the tracked tokens that another page stored
 // since this page's last save (takeStoredTrackedTokens() in state.js). The
 // switch then puts them away under the previous network, the network they were
-// added on. When the stored record is on another network, a switch saved
-// elsewhere has not reached this page yet. The stored record's tokens are then
-// that network's, and none are taken.
+// added on.
 async function onChainSwitch(newNetworkId) {
-    const { state, saveState, takeStoredTrackedTokens } = require("./state");
+    const {
+        state,
+        saveState,
+        takeStoredNetwork,
+        takeStoredTrackedTokens,
+    } = require("./state");
     let net = null;
     await saveState((stored) => {
         if (state.networkId === newNetworkId) return false;
-        if (stored.networkId === state.networkId) {
-            takeStoredTrackedTokens(stored);
-        }
+        if (stored.networkId !== state.networkId) takeStoredNetwork(stored);
+        takeStoredTrackedTokens(stored);
         net = applyChainSwitchFields(state, newNetworkId);
         stored.lastBalanceRefresh = 0;
         stored.fraudContracts = [];

src/shared/state.js

@@ -527,6 +527,14 @@ async function saveStateOnce(beforeWrite) {
             merged[key] = current[key];
         }
     }
+    // When the merged record names a network other than this page's, this page
+    // has not yet taken a switch saved elsewhere. This page's `trackedTokens`
+    // is then the list of the network that this page still has. So the merged
+    // record keeps the stored list
+    // (https://git.eeqj.de/sneak/AutistMask/issues/701).
+    if (merged.networkId !== current.networkId) {
+        merged.trackedTokens = fresh.trackedTokens;
+    }
     merged.hasWallet = Boolean(merged.wallets && merged.wallets.length > 0);
     // Stamped on every write, never merged or diffed: the record that goes to
     // storage is in THIS build's shape whatever shape it was read in, which is
@@ -608,11 +616,12 @@ function saveState(beforeWrite) {
 }
 
 // Give this page the network switch held by `stored`, a record a save of this
-// page has just read (followStoredSettings() in src/popup/index.js calls this
-// from `beforeWrite`), in `state` and in `baseline` alike, as loadState() does
-// with a whole record. The switch is then not this page's own change, even when
-// that save fails to write: a later switch back to the previous network still
-// differs from `baseline`, and is stored.
+// page has just read (followStoredSettings() in src/popup/index.js and
+// onChainSwitch() in src/shared/chainSwitch.js call this from `beforeWrite`),
+// in `state` and in `baseline` alike, as loadState() does with a whole
+// record. The switch is then not this page's own change, even when that save
+// fails to write: a later switch back to the previous network still differs
+// from `baseline`, and is stored.
 function takeStoredNetwork(stored) {
     copyChainSwitchFields(rawState, stored);
     copyChainSwitchFields(baseline, structuredClone(stored));