docs: put Sepolia in scope and write down the provider flag exception (closes #165)

The README's 1.0 non-goal said Ethereum mainnet only, while Sepolia
ships as a selectable network. It now puts mainnet and Sepolia in scope
and other chains out of it.

The injected provider's flag named after the other wallet stays, as an
interface-compatibility flag many dApps check. It is now written down
as an exception to the rule against naming competitors, in the README's
Policies section and in RULES.md, and the comment beside it says so.
Neither document spells the name, so script/check-censored, which
already allows the flag only in src/content/inpage.js and its built
copies, is unchanged.

Model: opus-5-5

README.md

@@ -1263,14 +1263,21 @@ path rather than on the home screen. Read the claim narrowly, as that file
 states it: what those boots prove is no structural dereference on the code paths
 a WHOLLY-CORRUPTED PROFILE takes, which is not every path a stored record takes.
 Not driven: any pairing of values the four slots do not produce, a view only
-forward navigation opens, anything behind a click, and everything a healthy
-profile reaches. Within that boundary the verdict is unconditional — if one of
-those boots leaves the popup unhealthy or off the view it stored, `make check`
-fails, including when it takes two corrupted fields at once, because the verdict
-is the combined boot and the per-field re-boot that names a culprit can only
-decorate the message. So does a field that gains a floor while its row still
-claims it has none, and so does a field added to `PERSISTED_FIELDS` with no row
-at all. The per-field justification that used to live in the header of
+forward navigation opens, anything behind a click or a timer, and, of what a
+healthy profile reaches, anything beyond its boot onto each view the popup can
+reopen onto. The fields the router does not read share a slot on each boot, so
+one of them truthy while another is falsy is reached only where the falsy slot
+pairs a field that cannot be falsy with one that is. Within that boundary the
+verdict is unconditional — if one of those boots leaves the popup unhealthy,
+`make check` fails, including when it takes two corrupted fields at once,
+because the verdict is the combined boot and the per-field re-boot that names a
+culprit can only decorate the message. The combined boot must also land on the
+view it stored, and each value driven only onto the restore path must land on
+its view, or fall back to Home, as its row declares; a field the router reads
+can legitimately change which view renders, so its own sweep is held to health
+alone. `make check` also fails on a field that gains a floor while its row still
+claims it has none, and on a field added to `PERSISTED_FIELDS` with no row at
+all. The per-field justification that used to live in the header of
 `src/shared/stateSchema.js` shipped a false claim in three consecutive changes,
 each caught only by a reviewer re-deriving thirty fields by hand.
 
@@ -1444,14 +1451,17 @@ view would leave a wallet one click from deletion.
       without it, the lost-password route on DeleteWallet is the first they
       would hear of it. The hint line reserves its height, so switching tabs
       cannot move the password fields under the pointer.
-    - "Import" button
+    - "Import" button, with the error line beside it so that it adds no height
+      to a screen whose button already starts near the bottom of the popup
 - **Transitions**:
     - "Import" with a valid entry and a matching password of at least 12
       characters → creates the wallet, clears the navigation stack, and →
       **Home**. The phrase and xprv modes then scan for further used addresses
       and report the count as a flash message.
-    - "Import" with an invalid entry, a duplicate wallet or address, or a short
-      or mismatched password → flash message, no screen change
+    - "Import" with a missing, short or mismatched password → full-sentence
+      error on the error line, no screen change
+    - "Import" with an invalid entry or a duplicate wallet or address → flash
+      message, no screen change
     - "Back" → previous screen (Welcome, Home, or Settings)
 
 #### AddressDetail (`address`)
@@ -1490,8 +1500,8 @@ view would leave a wallet one click from deletion.
       copy)
     - Warning that anyone holding the private key can transfer all funds from
       the address
-    - Error line
-    - Password input and "Reveal" button, shown until the key is revealed
+    - Password input, error line and "Reveal" button, shown until the key is
+      revealed
     - The private key on a highlighted background, tap to copy, shown only after
       the password has been accepted
 - **Transitions**:
@@ -1829,8 +1839,8 @@ view would leave a wallet one click from deletion.
     - Wallet name
     - Warning box stating that anyone holding these words can take everything in
       the wallet, from any device, without the password
-    - Error line
-    - Password input + "Reveal" button, shown until the password is accepted
+    - Password input, error line and "Reveal" button, shown until the password
+      is accepted
     - The recovery phrase itself, in full and click-to-copy, shown only after a
       correct password and in place of the password prompt
 - **Transitions**:
@@ -1859,8 +1869,8 @@ view would leave a wallet one click from deletion.
     - "Back" button, "Delete Wallet" heading
     - Warning naming the wallet and stating that deletion is permanent and any
       funds are unrecoverable without the recovery phrase
-    - Error line
     - Password input
+    - Error line
     - "Confirm Delete" button
     - An underlined "I have lost my password" control
 - **Transitions**:
@@ -2638,7 +2648,7 @@ Currently supported:
 
 ### Non-Goals for 1.0
 
-- Multi-chain support (Ethereum mainnet only)
+- Chains other than Ethereum mainnet and the Sepolia testnet
 - Hardware wallet support
 
 ## TODO
@@ -2672,7 +2682,10 @@ Currently supported:
 ## Policies
 
 - We don't mention "the other wallet" by name in code or documentation. We're
-  our own thing.
+  our own thing. Written exception: the injected provider in
+  `src/content/inpage.js` sets the flag named after the other wallet to `true`.
+  It is an interface-compatibility flag many dApps check, and without it the
+  wallet stops working on their sites.
 - The README is the complete authoritative technical documentation. It's ok if
   it gets big.
 

RULES.md

@@ -118,4 +118,7 @@ contradicts either, the originals govern.
 - [ ] "Address" not "account" or "derived key"
 - [ ] "Password" not "encryption key" or "vault passphrase"
 - [ ] Error messages are full sentences
-- [ ] No competitor mentioned by name in code or documentation
+- [ ] No competitor mentioned by name in code or documentation. Written
+      exception: the injected provider in `src/content/inpage.js` sets the flag
+      named after the other wallet to `true`, an interface-compatibility flag
+      many dApps check (README.md, Policies)

TODO.md

@@ -44,6 +44,43 @@ then continue tagging as milestones land.
 
 # Completed Steps
 
+- 2026-10-07: Two contradictions between the documents and the code are resolved
+  as ruled on [#165](https://git.eeqj.de/sneak/AutistMask/issues/165). The
+  README's 1.0 non-goal now puts Ethereum mainnet and the Sepolia testnet in
+  scope and other chains out of it. The injected provider's flag named after the
+  other wallet stays, as an interface-compatibility flag many dApps check, and
+  is written down as an exception to the rule against naming competitors in the
+  README's Policies section, in `RULES.md` and in a comment beside it in
+  `src/content/inpage.js`. `script/check-censored` already allows that flag only
+  in that file and its built copies, so it is unchanged.
+
+- 2026-10-07: Two holes in what `tests/persistedFieldContract.test.js` checks
+  are closed ([#379](https://git.eeqj.de/sneak/AutistMask/issues/379)). The
+  check that every swept field is driven both truthy and falsy counts only
+  `hostile` and `falsy` values, which the sweep drives onto every restorable
+  view, and no longer a `hostileRestore` value, which reaches only the views its
+  entry names; the stale index 5 moves into `hostile` for `selectedWallet` and
+  `selectedAddress`, as the one value of either still truthy after the floor.
+  Each `hostileRestore` entry declares whether its boot lands on its view or
+  falls back to Home, and is held to it. The limits that remain, fields that
+  share a slot on one boot and anything no stored record reaches by itself, are
+  restated as built in the file's header and the README, which now also say
+  which boots are held to where the popup lands and that a healthy profile is
+  booted onto every restorable view.
+
+- 2026-10-07: Every password error in the popup is shown the same way
+  ([#493](https://git.eeqj.de/sneak/AutistMask/issues/493)): with `showError()`
+  and `hideError()` in a fixed-height error line below the password field, as
+  the send confirmation and approval screens already did. The add wallet screen
+  showed a missing, short or mismatched password in the flash line, and the
+  private key export, recovery phrase and delete wallet screens each had a line
+  of their own above the field. On the add wallet screen the line sits beside
+  the Import button, so the button stays where it was at 360x600. Each line
+  clears when the screen is shown again and when the password is tried again.
+  The add wallet screen's other messages, such as an invalid recovery phrase, a
+  duplicate wallet and the address scan, stay in the flash line.
+  `tests/passwordErrorLines.test.js` drives all four screens in the popup.
+
 - 2026-10-07: Pre-1.0 security review of the extension
   ([#383](https://git.eeqj.de/sneak/AutistMask/issues/383)), reading the tree at
   `99292b9` for key handling, the DEBUG mode policy, and what the background

src/content/inpage.js

@@ -99,7 +99,10 @@
 
     const provider = {
         isAutistMask: true,
-        isMetaMask: true, // compatibility — many dApps check this
+        // An interface-compatibility flag many dApps check. Kept as a written
+        // exception to the rule that no competitor is named in code: see
+        // Policies in README.md, and RULES.md.
+        isMetaMask: true,
         chainId: currentChainId,
         networkVersion: currentNetworkVersion,
         selectedAddress: null,

src/popup/index.html

@@ -207,12 +207,22 @@
                         class="border border-border p-1 w-full font-mono text-sm bg-bg text-fg"
                     />
                 </div>
-                <button
-                    id="btn-add-wallet-confirm"
-                    class="border border-border px-2 py-1 hover:bg-fg hover:text-bg cursor-pointer"
-                >
-                    Import
-                </button>
+                <!-- The error line sits beside Import, not above it: at
+                     360x600 the button already starts near the bottom of
+                     the popup, and a line of its own would push it below
+                     the fold. The longest error fits on one line here. -->
+                <div class="flex items-center gap-2">
+                    <button
+                        id="btn-add-wallet-confirm"
+                        class="border border-border px-2 py-1 hover:bg-fg hover:text-bg cursor-pointer"
+                    >
+                        Import
+                    </button>
+                    <div
+                        id="add-wallet-password-error"
+                        class="text-xs min-h-[1.25rem] invisible"
+                    ></div>
+                </div>
             </div>
 
             <!-- ============ MAIN VIEW: ALL WALLETS & ADDRESSES ============ -->
@@ -396,10 +406,6 @@
                     Warning: anyone with this private key can access and
                     transfer all funds from this address. Never share it.
                 </p>
-                <div
-                    id="export-privkey-flash"
-                    class="text-xs mb-2 min-h-[1.25rem] invisible"
-                ></div>
                 <div id="export-privkey-password-section" class="mb-2">
                     <label class="block mb-1">Password</label>
                     <input
@@ -408,9 +414,13 @@
                         class="border border-border p-1 w-full font-mono text-sm bg-bg text-fg"
                         placeholder="Enter your password to continue"
                     />
+                    <div
+                        id="export-privkey-password-error"
+                        class="text-xs mt-2 mb-2 min-h-[1.25rem] invisible"
+                    ></div>
                     <button
                         id="btn-export-privkey-confirm"
-                        class="border border-border px-2 py-1 hover:bg-fg hover:text-bg cursor-pointer mt-2"
+                        class="border border-border px-2 py-1 hover:bg-fg hover:text-bg cursor-pointer"
                     >
                         Reveal
                     </button>
@@ -1116,10 +1126,6 @@
                     <strong id="delete-wallet-name"></strong> is permanent. Any
                     funds will be unrecoverable without your recovery phrase.
                 </p>
-                <div
-                    id="delete-wallet-flash"
-                    class="text-xs text-red-500 mb-2 min-h-[1.25rem] invisible"
-                ></div>
                 <div class="mb-2">
                     <label class="block mb-1">Password</label>
                     <input
@@ -1129,6 +1135,10 @@
                         placeholder="Enter your password to confirm"
                     />
                 </div>
+                <div
+                    id="delete-wallet-password-error"
+                    class="text-xs mb-2 min-h-[1.25rem] invisible"
+                ></div>
                 <button
                     id="btn-delete-wallet-confirm"
                     class="border border-border text-red-500 px-2 py-1 hover:bg-fg hover:text-bg cursor-pointer"
@@ -1273,10 +1283,6 @@
                     this wallet, from any device, without your password. Never
                     type them into a website and never show them to anyone.
                 </div>
-                <div
-                    id="show-phrase-flash"
-                    class="text-xs text-red-500 mb-2 min-h-[1.25rem] invisible"
-                ></div>
                 <div id="show-phrase-password-section" class="mb-2">
                     <label class="block mb-1">Password</label>
                     <input
@@ -1285,9 +1291,13 @@
                         class="border border-border p-1 w-full font-mono text-sm bg-bg text-fg"
                         placeholder="Enter your password to continue"
                     />
+                    <div
+                        id="show-phrase-password-error"
+                        class="text-xs mt-2 mb-2 min-h-[1.25rem] invisible"
+                    ></div>
                     <button
                         id="btn-show-phrase-reveal"
-                        class="border border-border px-2 py-1 hover:bg-fg hover:text-bg cursor-pointer mt-2"
+                        class="border border-border px-2 py-1 hover:bg-fg hover:text-bg cursor-pointer"
                     >
                         Reveal
                     </button>

src/popup/views/addWallet.js

@@ -2,6 +2,8 @@ const {
     $,
     showView,
     showFlash,
+    showError,
+    hideError,
     goBack,
     clearViewStack,
     onViewLeave,
@@ -98,6 +100,7 @@ function clear() {
     $("add-wallet-password").value = "";
     $("add-wallet-password-confirm").value = "";
     $("add-wallet-phrase-warning").style.visibility = "hidden";
+    hideError("add-wallet-password-error");
 }
 
 // Each wallet has its own password (its own encryptedSecret), so adding a
@@ -125,15 +128,18 @@ function validatePassword() {
     const pw = $("add-wallet-password").value;
     const pw2 = $("add-wallet-password-confirm").value;
     if (!pw) {
-        showFlash("Please choose a password.");
+        showError("add-wallet-password-error", "Please choose a password.");
         return null;
     }
     if (pw.length < 12) {
-        showFlash("Password must be at least 12 characters.");
+        showError(
+            "add-wallet-password-error",
+            "Password must be at least 12 characters.",
+        );
         return null;
     }
     if (pw !== pw2) {
-        showFlash("Passwords do not match.");
+        showError("add-wallet-password-error", "Passwords do not match.");
         return null;
     }
     return pw;
@@ -342,8 +348,10 @@ function init(ctx) {
         $("add-wallet-phrase-warning").style.visibility = "visible";
     });
 
-    // Import / confirm
+    // Import / confirm. Each press starts with no password error on screen:
+    // validatePassword() puts it back if the password is still wrong.
     $("btn-add-wallet-confirm").addEventListener("click", async () => {
+        hideError("add-wallet-password-error");
         if (currentMode === "mnemonic") {
             await importMnemonic(ctx);
         } else if (currentMode === "privkey") {

src/popup/views/deleteWallet.js

@@ -2,6 +2,8 @@ const {
     $,
     showView,
     showFlash,
+    showError,
+    hideError,
     goBack,
     clearViewStack,
     onViewLeave,
@@ -55,8 +57,7 @@ function confirmKey(name) {
 function clear() {
     deleteWalletIndex = null;
     $("delete-wallet-password").value = "";
-    $("delete-wallet-flash").textContent = "";
-    $("delete-wallet-flash").style.visibility = "hidden";
+    hideError("delete-wallet-password-error");
 }
 
 // The lost-password screen holds no secret — a wallet name is not one —
@@ -232,19 +233,22 @@ function init(_ctx) {
     $("btn-delete-wallet-confirm").addEventListener("click", async () => {
         const pw = $("delete-wallet-password").value;
         if (!pw) {
-            $("delete-wallet-flash").textContent =
-                "Please enter your password.";
-            $("delete-wallet-flash").style.visibility = "visible";
+            showError(
+                "delete-wallet-password-error",
+                "Please enter your password.",
+            );
             return;
         }
 
         if (deleteWalletIndex === null) {
-            $("delete-wallet-flash").textContent =
-                "No wallet selected for deletion.";
-            $("delete-wallet-flash").style.visibility = "visible";
+            showError(
+                "delete-wallet-password-error",
+                "No wallet selected for deletion.",
+            );
             return;
         }
 
+        hideError("delete-wallet-password-error");
         const btn = $("btn-delete-wallet-confirm");
         btn.disabled = true;
         btn.classList.add("text-muted");
@@ -256,9 +260,10 @@ function init(_ctx) {
         try {
             await decryptWithPassword(wallet.encryptedSecret, pw);
         } catch {
-            $("delete-wallet-flash").textContent =
-                "That password is incorrect. Please try again.";
-            $("delete-wallet-flash").style.visibility = "visible";
+            showError(
+                "delete-wallet-password-error",
+                "That password is incorrect. Please try again.",
+            );
             btn.disabled = false;
             btn.classList.remove("text-muted");
             return;

src/popup/views/exportPrivkey.js

@@ -20,6 +20,8 @@ const {
     $,
     showView,
     showFlash,
+    showError,
+    hideError,
     flashCopyFeedback,
     goBack,
     onViewLeave,
@@ -56,11 +58,6 @@ function isCurrentReveal(generation) {
     );
 }
 
-function fail(message) {
-    $("export-privkey-flash").textContent = message;
-    $("export-privkey-flash").style.visibility = "visible";
-}
-
 // Wipe every trace of the key and drop the address selection. Safe to call
 // when nothing was ever revealed, and safe to call twice.
 function clear() {
@@ -71,8 +68,7 @@ function clear() {
     $("export-privkey-password").value = "";
     $("export-privkey-result").classList.add("hidden");
     $("export-privkey-password-section").classList.remove("hidden");
-    $("export-privkey-flash").textContent = "";
-    $("export-privkey-flash").style.visibility = "hidden";
+    hideError("export-privkey-password-error");
 }
 
 function show(walletIdx, addrIdx) {
@@ -112,15 +108,19 @@ function show(walletIdx, addrIdx) {
 async function reveal() {
     const password = $("export-privkey-password").value;
     if (!password) {
-        fail("Please enter your password.");
+        showError(
+            "export-privkey-password-error",
+            "Please enter your password.",
+        );
         return;
     }
     if (walletIndex === null) {
-        fail("No address is selected.");
+        showError("export-privkey-password-error", "No address is selected.");
         return;
     }
     const wallet = state.wallets[walletIndex];
 
+    hideError("export-privkey-password-error");
     const btn = $("btn-export-privkey-confirm");
     btn.disabled = true;
     btn.classList.add("text-muted");
@@ -140,11 +140,12 @@ async function reveal() {
         $("export-privkey-password-section").classList.add("hidden");
         $("export-privkey-value").textContent = signer.privateKey;
         $("export-privkey-result").classList.remove("hidden");
-        $("export-privkey-flash").textContent = "";
-        $("export-privkey-flash").style.visibility = "hidden";
     } catch {
         if (!isCurrentReveal(generation)) return;
-        fail("That password is incorrect. Please try again.");
+        showError(
+            "export-privkey-password-error",
+            "That password is incorrect. Please try again.",
+        );
     } finally {
         btn.disabled = false;
         btn.classList.remove("text-muted");

src/popup/views/showPhrase.js

@@ -21,6 +21,8 @@ const {
     $,
     showView,
     showFlash,
+    showError,
+    hideError,
     flashCopyFeedback,
     goBack,
     onViewLeave,
@@ -52,11 +54,6 @@ function isCurrentReveal(generation) {
     );
 }
 
-function fail(message) {
-    $("show-phrase-flash").textContent = message;
-    $("show-phrase-flash").style.visibility = "visible";
-}
-
 // Wipe every trace of the phrase and drop the wallet selection. Safe to
 // call when nothing was ever revealed, and safe to call twice.
 function clear() {
@@ -66,8 +63,7 @@ function clear() {
     $("show-phrase-password").value = "";
     $("show-phrase-result").classList.add("hidden");
     $("show-phrase-password-section").classList.remove("hidden");
-    $("show-phrase-flash").textContent = "";
-    $("show-phrase-flash").style.visibility = "hidden";
+    hideError("show-phrase-password-error");
 }
 
 function show(walletIdx) {
@@ -90,19 +86,23 @@ function show(walletIdx) {
 async function reveal() {
     const password = $("show-phrase-password").value;
     if (!password) {
-        fail("Please enter your password.");
+        showError("show-phrase-password-error", "Please enter your password.");
         return;
     }
     if (walletIndex === null) {
-        fail("No wallet is selected.");
+        showError("show-phrase-password-error", "No wallet is selected.");
         return;
     }
     const wallet = state.wallets[walletIndex];
     if (!walletHasRecoveryPhrase(wallet)) {
-        fail("This wallet does not have a recovery phrase.");
+        showError(
+            "show-phrase-password-error",
+            "This wallet does not have a recovery phrase.",
+        );
         return;
     }
 
+    hideError("show-phrase-password-error");
     const btn = $("btn-show-phrase-reveal");
     btn.disabled = true;
     btn.classList.add("text-muted");
@@ -120,13 +120,14 @@ async function reveal() {
         $("show-phrase-password-section").classList.add("hidden");
         $("show-phrase-value").textContent = phrase;
         $("show-phrase-result").classList.remove("hidden");
-        $("show-phrase-flash").textContent = "";
-        $("show-phrase-flash").style.visibility = "hidden";
     } catch {
         if (!isCurrentReveal(generation)) return;
         // Deliberately not the caught error: the message is fixed so that
         // nothing derived from the ciphertext or the attempt can surface.
-        fail("That password is incorrect. Please try again.");
+        showError(
+            "show-phrase-password-error",
+            "That password is incorrect. Please try again.",
+        );
     } finally {
         btn.disabled = false;
         btn.classList.remove("text-muted");

tests/addressScanCancelled.test.js

@@ -39,6 +39,8 @@ jest.doMock("../src/popup/views/helpers", () => ({
     $: element,
     showView: () => {},
     showFlash: () => {},
+    showError: () => {},
+    hideError: () => {},
     goBack: () => {},
     clearViewStack: () => {},
     onViewLeave: () => {},

tests/deleteWalletLostPassword.test.js

@@ -253,7 +253,7 @@ describe("reaching the screen", () => {
         const { decryptWithPassword } = require("../src/shared/vault");
         decryptWithPassword.mockRejectedValue(new Error("nope"));
         await click("btn-delete-wallet-confirm");
-        expect(node("delete-wallet-flash").textContent).toBe(
+        expect(node("delete-wallet-password-error").textContent).toBe(
             "That password is incorrect. Please try again.",
         );
     });

tests/e2e/run.js

@@ -809,7 +809,7 @@ async function secretScreenState(page, view) {
     return page.evaluate(
         (v) => ({
             value: document.getElementById(v + "-value").textContent,
-            error: document.getElementById(v + "-flash").textContent,
+            error: document.getElementById(v + "-password-error").textContent,
             html: document.getElementById("view-" + v).innerHTML,
             resultHidden: document
                 .getElementById(v + "-result")
@@ -906,7 +906,8 @@ test("a wrong password reveals nothing (#161)", async (env) => {
     await env.page.click("#btn-show-phrase-reveal");
     await env.page.waitForFunction(
         () =>
-            document.getElementById("show-phrase-flash").textContent.length > 0,
+            document.getElementById("show-phrase-password-error").textContent
+                .length > 0,
         null,
         { timeout: 60000 },
     );
@@ -1993,13 +1994,14 @@ test("an over-long flash message keeps to one line (#252)", async (env) => {
 
 // Every screen that asks for a password reserves room for one line of error.
 // The two on the dApp approval screens also have a border and padding, which
-// that reserved height has to cover too.
+// that reserved height has to cover too. The add wallet screen's line sits
+// beside its button rather than above it, and has its own test below.
 const PASSWORD_ERROR_CONTAINERS = [
     "approve-tx-error",
     "approve-sign-error",
-    "export-privkey-flash",
-    "show-phrase-flash",
-    "delete-wallet-flash",
+    "export-privkey-password-error",
+    "show-phrase-password-error",
+    "delete-wallet-password-error",
     "confirm-tx-password-error",
 ];
 
@@ -2064,6 +2066,107 @@ test("a password error moves nothing on any screen (#297)", async (env) => {
     }
 });
 
+// ------------------------------------------ add wallet Import button (#493)
+
+// At 360x600 the add wallet screen's Import button already starts near the
+// bottom of the popup, so its password error line sits beside the button
+// rather than above it. Measures the button and the line empty and again
+// filled with the longest error addWallet.js puts there. Runs in the page.
+function measureImportButton() {
+    const button = document.getElementById("btn-add-wallet-confirm");
+    const line = document.getElementById("add-wallet-password-error");
+    const measure = () => {
+        const b = button.getBoundingClientRect();
+        const l = line.getBoundingClientRect();
+        return {
+            buttonTop: b.top + window.scrollY,
+            buttonBottom: b.bottom + window.scrollY,
+            lineTop: l.top + window.scrollY,
+            lineBottom: l.bottom + window.scrollY,
+        };
+    };
+    const empty = measure();
+    line.textContent = "Password must be at least 12 characters.";
+    line.style.visibility = "visible";
+    const filled = measure();
+    line.textContent = "";
+    line.style.visibility = "hidden";
+    return { empty, filled };
+}
+
+test("the add wallet password error leaves Import where it was (#493)", async (env) => {
+    const page = await openPopup(env.ctx, env.popupUrl);
+    try {
+        await page.setViewportSize(POPUP_VIEWPORT);
+        // Brought up by toggling classes, as in the test above. The note
+        // addWallet.js shows once a wallet exists is the only part of the
+        // screen that differs between the first wallet and a later one.
+        await page.evaluate(() => {
+            const screen = document.getElementById("view-add-wallet");
+            for (const view of document.querySelectorAll(".view")) {
+                view.classList.toggle("hidden", view !== screen);
+            }
+        });
+        for (const walletExists of [false, true]) {
+            await page.evaluate(
+                (shown) =>
+                    document
+                        .getElementById("add-wallet-separate-password-note")
+                        .classList.toggle("hidden", !shown),
+                walletExists,
+            );
+            for (const tab of ["tab-mnemonic", "tab-privkey", "tab-xprv"]) {
+                await page.click("#" + tab);
+                const { empty, filled } =
+                    await page.evaluate(measureImportButton);
+                const where =
+                    "#" +
+                    tab +
+                    (walletExists
+                        ? " with a wallet already added"
+                        : " for the first wallet");
+                // Printed pass or fail, as the dust threshold test does.
+                console.log(
+                    "# add wallet Import top, " +
+                        where +
+                        ": " +
+                        empty.buttonTop +
+                        "px",
+                );
+                for (const m of [empty, filled]) {
+                    assert(
+                        m.lineTop >= m.buttonTop &&
+                            m.lineBottom <= m.buttonBottom,
+                        "the error line on " +
+                            where +
+                            " does not fit beside Import, so it adds height: " +
+                            JSON.stringify(m),
+                    );
+                }
+                assert(
+                    filled.buttonTop === empty.buttonTop,
+                    "Import moved " +
+                        (filled.buttonTop - empty.buttonTop) +
+                        "px when the error appeared on " +
+                        where,
+                );
+                if (!walletExists) {
+                    assert(
+                        empty.buttonTop < POPUP_VIEWPORT.height,
+                        "Import starts at " +
+                            empty.buttonTop +
+                            "px on " +
+                            where +
+                            ", below the fold",
+                    );
+                }
+            }
+        }
+    } finally {
+        await page.close();
+    }
+});
+
 // --------------------------------------------- confirmation screen (#238)
 //
 // The screen that decides what gets signed. The arithmetic underneath it

tests/exportPrivkey.test.js

@@ -207,7 +207,7 @@ describe("a decrypt still running when the screen is left", () => {
     });
 
     // Same hole on the failure path: a wrong-password error written after
-    // the wipe would restore the flash line on a screen the user has left.
+    // the wipe would restore the error line on a screen the user has left.
     test("never writes the failure message either", async () => {
         const { helpers, vault, exportPrivkey } = load();
         exportPrivkey.show(0, 0);
@@ -217,8 +217,10 @@ describe("a decrypt still running when the screen is left", () => {
         reveal.reject(new Error("decryption failed"));
         await reveal.pending;
 
-        expect(node("export-privkey-flash").textContent).toBe("");
-        expect(node("export-privkey-flash").style.visibility).toBe("hidden");
+        expect(node("export-privkey-password-error").textContent).toBe("");
+        expect(node("export-privkey-password-error").style.visibility).toBe(
+            "hidden",
+        );
     });
 });
 
@@ -260,7 +262,7 @@ describe("a reveal that is not interrupted", () => {
         await reveal.pending;
 
         expect(node("export-privkey-value").textContent).toBe("");
-        expect(node("export-privkey-flash").textContent).toBe(
+        expect(node("export-privkey-password-error").textContent).toBe(
             "That password is incorrect. Please try again.",
         );
     });

tests/passwordErrorLines.test.js

@@ -0,0 +1,159 @@
+// Every screen that asks for a password shows a password error the same way:
+// through showError() and hideError() in src/popup/views/helpers.js, in a
+// fixed-height error line below the password field, and never in the flash
+// line at the top of the popup
+// (https://git.eeqj.de/sneak/AutistMask/issues/493). These boot the real popup
+// over src/popup/index.html, so each error line has to exist in the markup,
+// and check that the error appears in it and clears again.
+
+jest.mock("../src/shared/vault", () => ({
+    decryptWithPassword: jest.fn(),
+    encryptWithPassword: jest.fn(),
+}));
+
+const {
+    bootPopup,
+    cleanupPopup,
+    unversionedValidProfile,
+} = require("./support/popupBoot");
+
+const PASSWORD = "correct horse battery staple";
+const WRONG_PASSWORD = "That password is incorrect. Please try again.";
+
+afterEach(() => {
+    cleanupPopup();
+});
+
+// The error line as the user sees it.
+function errorLine(page, id) {
+    return {
+        inMarkup: page.document.authoredIds.has(id),
+        text: page.text(id),
+        visibility: page.node(id).style.visibility,
+    };
+}
+
+function shown(text) {
+    return { inMarkup: true, text, visibility: "visible" };
+}
+
+const cleared = { inMarkup: true, text: "", visibility: "hidden" };
+
+describe("the add wallet screen", () => {
+    const ERROR = "add-wallet-password-error";
+
+    // First run: Welcome, "Add wallet", then the die for a valid phrase.
+    async function openAddWallet() {
+        const page = await bootPopup(undefined);
+        await page.click("btn-welcome-add");
+        await page.click("btn-generate-phrase");
+        return page;
+    }
+
+    function setPasswords(page, password, confirm) {
+        page.node("add-wallet-password").value = password;
+        page.node("add-wallet-password-confirm").value = confirm;
+    }
+
+    test("shows a password problem below the password fields, and clears it on the next press", async () => {
+        const page = await openAddWallet();
+        setPasswords(page, "short", "short");
+        await page.click("btn-add-wallet-confirm");
+        expect(errorLine(page, ERROR)).toEqual(
+            shown("Password must be at least 12 characters."),
+        );
+        expect(page.text("flash-msg")).toBe("");
+
+        // The password is fixed and the phrase emptied: the password error
+        // goes, and the phrase problem is still reported in the flash line.
+        setPasswords(page, PASSWORD, PASSWORD);
+        page.node("wallet-mnemonic").value = "";
+        await page.click("btn-add-wallet-confirm");
+        expect(errorLine(page, ERROR)).toEqual(cleared);
+        expect(page.text("flash-msg")).toBe(
+            "Enter a recovery phrase, or press the die.",
+        );
+
+        // Leaving clears the flash line and stops its timer, which would
+        // otherwise fire after this page is gone.
+        await page.click("btn-add-wallet-back");
+    });
+
+    test("clears the error when the screen is shown again", async () => {
+        const page = await openAddWallet();
+        setPasswords(page, PASSWORD, PASSWORD + " typo");
+        await page.click("btn-add-wallet-confirm");
+        expect(errorLine(page, ERROR)).toEqual(
+            shown("Passwords do not match."),
+        );
+
+        await page.click("btn-add-wallet-back");
+        await page.click("btn-welcome-add");
+        expect(errorLine(page, ERROR)).toEqual(cleared);
+    });
+});
+
+describe.each([
+    {
+        screen: "the private key export screen",
+        open: () => require("../src/popup/views/exportPrivkey").show(0, 0),
+        field: "export-privkey-password",
+        button: "btn-export-privkey-confirm",
+        error: "export-privkey-password-error",
+    },
+    {
+        screen: "the recovery phrase screen",
+        open: () => require("../src/popup/views/showPhrase").show(0),
+        field: "show-phrase-password",
+        button: "btn-show-phrase-reveal",
+        error: "show-phrase-password-error",
+    },
+    {
+        screen: "the delete wallet screen",
+        open: () => require("../src/popup/views/deleteWallet").show(0),
+        field: "delete-wallet-password",
+        button: "btn-delete-wallet-confirm",
+        error: "delete-wallet-password-error",
+    },
+])("$screen", ({ open, field, button, error }) => {
+    // Opens the screen and enters a password the vault rejects.
+    async function failedAttempt() {
+        const page = await bootPopup(unversionedValidProfile());
+        open();
+        const { decryptWithPassword } = require("../src/shared/vault");
+        decryptWithPassword.mockRejectedValue(new Error("wrong password"));
+        page.node(field).value = "not the password";
+        await page.click(button);
+        return { page, decryptWithPassword };
+    }
+
+    test("shows a wrong password below the password field", async () => {
+        const { page } = await failedAttempt();
+        expect(errorLine(page, error)).toEqual(shown(WRONG_PASSWORD));
+    });
+
+    test("clears the error while the next password is checked", async () => {
+        const { page, decryptWithPassword } = await failedAttempt();
+        let rejectDecrypt;
+        decryptWithPassword.mockReturnValue(
+            new Promise((resolve, reject) => {
+                rejectDecrypt = reject;
+            }),
+        );
+
+        page.node(field).value = "another guess";
+        const pressed = page.click(button);
+        await page.settle();
+        expect(errorLine(page, error)).toEqual(cleared);
+
+        rejectDecrypt(new Error("wrong password"));
+        await pressed;
+        expect(errorLine(page, error)).toEqual(shown(WRONG_PASSWORD));
+    });
+
+    test("clears the error when the screen is shown again", async () => {
+        const { page } = await failedAttempt();
+        open();
+        expect(errorLine(page, error)).toEqual(cleared);
+    });
+});

tests/persistedFieldContract.test.js

@@ -49,22 +49,37 @@
 // every path a stored record takes, and the difference is the whole of what
 // this file does not cover:
 //
-//   - Only the values in the table, in the SLOT arrangement below: four value
-//     combinations per view, not the product of twelve fields. A dereference
-//     reached only under a pairing no slot produces is not driven at all.
-//   - Only what a stored record reaches by ITSELF. A view only forward
-//     navigation opens, and anything behind a click, is not driven.
-//   - Nothing about the paths a HEALTHY profile takes, which is most of the
-//     popup. This file is a floor under one defect class, not a proof about
-//     the renderers.
+//   - Only the values in the table, in the SLOT arrangement below. On the
+//     restore path the twelve fields the router does not read are corrupted
+//     together, every field on the same slot, so a view gets four value
+//     combinations of them, not their product. A branch entered only when one
+//     of them is truthy and another falsy is reached only where the falsy
+//     slot happens to pair a field that cannot be falsy with one that is.
+//     Each field the router reads is corrupted alone, over an otherwise
+//     well-formed record.
+//   - Only what a stored record reaches by ITSELF, as the boot renders it. A
+//     view only forward navigation opens, anything behind a click, and
+//     anything behind a timer (bootPopup() records every interval, and this
+//     file never runs one) is not driven.
+//   - Of the paths a HEALTHY profile takes, only its boot onto each
+//     restorable view ("the base profile the sweep corrupts" below). The rest
+//     of the popup is not covered: this file is a floor under one defect
+//     class, not a proof about the renderers.
 //
-// Within that boundary it is unconditional: if one of these boots leaves the
-// popup unhealthy or off the view it stored, this file goes red — including
-// when it takes two corrupted fields at once, because the verdict is the
-// combined boot itself and the per-field re-boot below can only decorate the
-// message. That last part is the one thing an earlier version got wrong: it
-// asserted on the per-field list, so an observed dead popup that no single
-// field reproduced was reported green.
+// Within that boundary it is unconditional: if a boot that corrupts a field
+// leaves the popup unhealthy, this file goes red — including when it takes
+// two corrupted fields at once, because the verdict is the combined boot
+// itself and the per-field re-boot below can only decorate the message. That
+// last part is the one thing an earlier version got wrong: it asserted on the
+// per-field list, so an observed dead popup that no single field reproduced
+// was reported green.
+//
+// Where the popup lands is held for some of those boots and not others. The
+// combined boot must land on the view it stored, and each `hostileRestore`
+// value must land on its view, or fall back to Home, as its entry declares.
+// The boots in "a hostile routing value restoring onto" are held to health
+// alone, because a value in a field the router reads legitimately changes
+// which view renders; so are the boots onto Home, which store no view.
 //
 // Booting every field separately at every value would be several hundred boots
 // and most of the suite's budget; this is forty-four. Widening it further is
@@ -128,7 +143,11 @@ const sweptValues = (row) => [...row.hostile, ...(row.falsy || [])];
 // list short and pointed. `floorOnly` is extra values checked against the
 // floor alone, which is pure and free. `hostileRestore` is extra values driven
 // through the restore path only, for a value that means nothing until a
-// particular branch's gate has let it past.
+// particular branch's gate has let it past. Each of its entries names the
+// `views` it is driven onto and declares whether the boot lands on them
+// (`restored: true`) or falls back to Home (`restored: false`), so a value
+// written for one renderer cannot stop reaching it unnoticed. A value driven
+// onto every restorable view is written with everyRestorableView() below.
 //
 // `falsy` is the other POLARITY of a swept field, driven for the same reason.
 // It is not a value src/ never writes — for three of these fields it is the
@@ -139,6 +158,23 @@ const sweptValues = (row) => [...row.hostile, ...(row.falsy || [])];
 // falsy value stored under that field comes back TRUTHY from the floor, so no
 // `!state.x` branch is reachable from a stored record at all.
 
+// The `hostileRestore` entries for a value driven onto every restorable view:
+// it falls back to Home on the views listed in `fallsBackOn` and lands on every
+// other one, so a view added to RESTORABLE_VIEWS is driven, and expected to
+// land, without editing the row.
+function everyRestorableView(value, fallsBackOn) {
+    return [
+        { value, views: fallsBackOn, restored: false },
+        {
+            value,
+            views: [...RESTORABLE_VIEWS].filter(
+                (view) => !fallsBackOn.includes(view),
+            ),
+            restored: true,
+        },
+    ];
+}
+
 const CONTRACT = [
     {
         field: "wallets",
@@ -280,28 +316,38 @@ const CONTRACT = [
         kind: KIND.SCALAR,
         // The prototype members are the whole point: `wallets["map"]` is
         // TRUTHY, so hasValidAddress()'s `&&` does not short-circuit and
-        // `.addresses[…]` throws. A stale INTEGER is the safe case.
-        hostile: ["map", "__proto__", { a: 1 }],
+        // `.addresses[…]` throws. A stale INTEGER is the safe case and has to
+        // stay so. 5 is one, out of range for the one wallet in the profile,
+        // and it is also this field's truthy polarity: every other value here
+        // comes back from the floor as null.
+        hostile: ["map", "__proto__", { a: 1 }, 5],
         floorOnly: ["length", "constructor", "toString", "0", -1, 1.5, true],
         holds: isIndexOrNull,
         // SCALAR, and swept anyway: the restore path is precisely why this
         // field gained a floor, so the sweep is the regression guard on it.
         alsoSweep: true,
         routes: true,
-        // A stale INTEGER index, which reaches the restore path by a different
-        // route from the prototype members above — falsy or out of range
-        // rather than truthy — and has to keep being the safe case.
-        hostileRestore: [{ value: "length" }, { value: 5 }],
+        // Comes back from the floor as null, which hasValidAddress() reads as
+        // nothing selected: the popup falls back to Home on the five views
+        // that need an address, and lands on every other one.
+        hostileRestore: everyRestorableView("length", [
+            "address",
+            "address-token",
+            "receive",
+            "transaction",
+            "confirm-tx",
+        ]),
     },
     {
         field: "selectedAddress",
         kind: KIND.SCALAR,
-        hostile: ["map", "__proto__", { a: 1 }],
+        // 5 for the same reason as in selectedWallet: a stale index, and the
+        // one value here still truthy after the floor.
+        hostile: ["map", "__proto__", { a: 1 }, 5],
         floorOnly: ["length", "constructor", "toString", "0", -1, 1.5, true],
         holds: isIndexOrNull,
         alsoSweep: true,
         routes: true,
-        hostileRestore: [{ value: 5 }],
     },
     {
         field: "currentView",
@@ -325,7 +371,9 @@ const CONTRACT = [
         // container shapes below onto every restorable view; hostileRestore
         // adds the records that PASS a branch's gate and then hand its
         // renderer something it dereferences, which is where the entries are
-        // actually decided.
+        // actually decided. The guard refuses each single-view record below,
+        // so each is declared to fall back to Home: one that started landing
+        // would be reaching the renderer it was written against.
         hostile: [42, "notarecord", { a: 1 }, [1, 2]],
         // `structuredClone(saved.viewData || {})`: the container is never falsy
         // in state whatever was stored, so no `!state.viewData` branch exists to
@@ -334,11 +382,20 @@ const CONTRACT = [
         hostileRestore: [
             // success-tx passes on `data.hash`, and renderSuccess() then calls
             // toAddressHtml(d.to) -> addressTitle() -> address.toLowerCase().
-            { value: { hash: "0x1" }, views: ["success-tx"] },
-            { value: { hash: "0x1", to: 42 }, views: ["success-tx"] },
+            {
+                value: { hash: "0x1" },
+                views: ["success-tx"],
+                restored: false,
+            },
+            {
+                value: { hash: "0x1", to: 42 },
+                views: ["success-tx"],
+                restored: false,
+            },
             {
                 value: { hash: "0x1", to: ADDRESS, decoded: { details: 7 } },
                 views: ["success-tx"],
+                restored: false,
             },
             {
                 value: {
@@ -347,12 +404,25 @@ const CONTRACT = [
                     decoded: { details: [{ address: 42 }] },
                 },
                 views: ["success-tx"],
+                restored: false,
             },
             // error-tx passes on `data.message`, same dereference.
-            { value: { message: "boom" }, views: ["error-tx"] },
-            { value: { message: "boom", to: 42 }, views: ["error-tx"] },
+            {
+                value: { message: "boom" },
+                views: ["error-tx"],
+                restored: false,
+            },
+            {
+                value: { message: "boom", to: 42 },
+                views: ["error-tx"],
+                restored: false,
+            },
             // transaction passes on `data.tx`.
-            { value: { tx: { hash: "0x1" } }, views: ["transaction"] },
+            {
+                value: { tx: { hash: "0x1" } },
+                views: ["transaction"],
+                restored: false,
+            },
             {
                 value: {
                     tx: {
@@ -363,9 +433,14 @@ const CONTRACT = [
                     },
                 },
                 views: ["transaction"],
+                restored: false,
             },
             // confirm-tx passes on `data.pendingTx`.
-            { value: { pendingTx: { amount: "1" } }, views: ["confirm-tx"] },
+            {
+                value: { pendingTx: { amount: "1" } },
+                views: ["confirm-tx"],
+                restored: false,
+            },
             {
                 value: {
                     pendingTx: {
@@ -376,6 +451,7 @@ const CONTRACT = [
                     },
                 },
                 views: ["confirm-tx"],
+                restored: false,
             },
             // wait-tx passes on `pendingWait.hash`; restoreWait() has checked
             // the fields below it since it was written, and this is the
@@ -388,20 +464,29 @@ const CONTRACT = [
                     },
                 },
                 views: ["wait-tx"],
+                restored: false,
             },
             // A record that passes EVERY branch's gate at once, driven onto
             // every restorable view: a branch a view does not read must stay
-            // one it does not read, and each renderer must survive the fields
-            // another branch left behind.
-            {
-                value: {
+            // one it does not read. The five views with a viewData branch
+            // refuse it; every other one renders it, and must survive the
+            // fields every branch left behind.
+            ...everyRestorableView(
+                {
                     hash: "0x1",
                     message: "boom",
                     tx: { hash: "0x1" },
                     pendingTx: { amount: "1" },
                     pendingWait: { hash: "0x1" },
                 },
-            },
+                [
+                    "confirm-tx",
+                    "transaction",
+                    "wait-tx",
+                    "success-tx",
+                    "error-tx",
+                ],
+            ),
         ],
     },
     {
@@ -583,6 +668,11 @@ const HEALTHY = { errors: [], blank: false };
 // set is all-truthy by construction, so without a falsy slot a dereference
 // behind `if (!state.x)` is never reached on the boot that corrupts x — the
 // same falsy-collapse blind spot the fields below were floored for.
+//
+// Only `hostile` and `falsy` values count. Those go through the sweep below,
+// which covers every restorable view; a `hostileRestore` entry is driven onto
+// only the views it names, so a polarity it alone supplied might reach a single
+// renderer.
 describe("both polarities of every swept field are driven", () => {
     const FALSY_STORED = [0, "", false, null];
     const floored = (field, value) =>
@@ -606,10 +696,9 @@ describe("both polarities of every swept field are driven", () => {
         test(`${row.field}: truthy and falsy`, () => {
             // What the boots below actually drive, floored the way a renderer
             // sees it — not what the row says it drives.
-            const driven = [
-                ...sweptValues(row),
-                ...(row.hostileRestore || []).map((entry) => entry.value),
-            ].map((value) => floored(row.field, value));
+            const driven = sweptValues(row).map((value) =>
+                floored(row.field, value),
+            );
 
             expect({
                 truthy: driven.some((value) => Boolean(value)),
@@ -865,20 +954,27 @@ describe("every field the router does not read, corrupted at once, onto", () =>
 
 // The values that only mean something on the restore path: a viewData that
 // PASSES a branch's gate and then hands its renderer something dereferenced,
-// and the index values whose route through hasValidAddress() differs from the
-// row's own hostile set.
+// and a selectedWallet the floor turns into nothing selected. Each boot must
+// throw nothing and show exactly the view its entry says it lands on: its own,
+// or Home, so a value written for one renderer cannot stop reaching it and
+// still pass.
 describe("a restore-only hostile value onto", () => {
     for (const row of CONTRACT) {
         for (const entry of row.hostileRestore || []) {
-            for (const view of entry.views || RESTORABLE_VIEWS) {
+            for (const view of entry.views) {
                 test(`${view}: ${row.field} = ${JSON.stringify(
                     entry.value,
                 )}`, async () => {
-                    await expect(
-                        bootHealth(
-                            restoringOnto(view, { [row.field]: entry.value }),
-                        ),
-                    ).resolves.toEqual(HEALTHY);
+                    const env = await bootPopup(
+                        restoringOnto(view, { [row.field]: entry.value }),
+                    );
+                    expect({
+                        errors: env.pageErrors,
+                        visible: env.visibleViews(),
+                    }).toEqual({
+                        errors: [],
+                        visible: [entry.restored ? view : "main"],
+                    });
                 });
             }
         }