fix: Settings stores the URL on screen when another page stored a different one (closes #688)

The RPC and Blockscout "Save" buttons in Settings now set the URL in the stored record, inside the save. The save writes only the fields that differ from what the page last saved. So a "Save" of the URL that this page loaded kept another page's different URL stored. The flash message still read "Saved.". A save refused because the network changed still stores nothing.

Model: opus-5-5

src/popup/views/settings.js

@@ -334,6 +334,11 @@ function showNewSettings() {
 // src/popup/index.js) between setting the URL and writing it. If the active
 // network is no longer `networkId`, on this page or in the stored record,
 // nothing is saved. The flash message then says that the network changed.
+//
+// The save writes only the fields that differ from what this page last saved.
+// Another page may have stored a different URL since then. So `url` is set in
+// the stored record too. "Saved." then means that the stored record holds
+// `url`.
 async function saveEndpoint(field, url, networkId) {
     let refused = false;
     await saveState((stored) => {
@@ -341,6 +346,7 @@ async function saveEndpoint(field, url, networkId) {
             state.networkId !== networkId || stored.networkId !== networkId;
         if (refused) return false;
         state[field] = url;
+        stored[field] = url;
     });
     if (refused) {
         showFlash("The URL was not saved because the network changed.");

tests/settingsEndpointSave.test.js

@@ -0,0 +1,49 @@
+// Another page stores a different RPC or Blockscout URL for the same network.
+// Then the user taps "Save" in Settings on this page, on the URL that this page
+// loaded. The URL on screen is stored, and the flash message reads "Saved."
+// (https://git.eeqj.de/sneak/AutistMask/issues/688). Driven through the real
+// popup over a stored profile on Ethereum Mainnet.
+
+const {
+    bootPopup,
+    cleanupPopup,
+    unversionedValidProfile,
+} = require("./support/popupBoot");
+const { NETWORKS } = require("../src/shared/networks");
+
+afterEach(() => {
+    cleanupPopup();
+});
+
+test.each([
+    { button: "btn-save-rpc", input: "settings-rpc", field: "rpcUrl" },
+    {
+        button: "btn-save-blockscout",
+        input: "settings-blockscout",
+        field: "blockscoutUrl",
+    },
+])(
+    "$button stores the URL on screen after another page stored a different one",
+    async ({ button, input, field }) => {
+        const page = await bootPopup(unversionedValidProfile());
+        await page.click("btn-settings");
+        const url = page.value(input);
+        // The browser is not made to tell this page of the other page's write.
+        page.storage.write("autistmask", {
+            ...page.storage.read("autistmask"),
+            [field]: "https://other-page.example.invalid",
+        });
+        // This answer passes both endpoint checks on Ethereum Mainnet. The RPC
+        // check reads Ethereum Mainnet's chain id from it. The Blockscout check
+        // reads `ok`.
+        globalThis.fetch.mockResolvedValue({
+            ok: true,
+            json: async () => ({ result: NETWORKS.mainnet.chainId }),
+        });
+
+        await page.click(button);
+
+        expect(page.storage.read("autistmask")[field]).toBe(url);
+        expect(page.text("flash-msg")).toBe("Saved.");
+    },
+);