fix: failed requests reach the page with an error code and the node's data (closes #533)

A request the node refuses now reaches the page with the node's own JSON-RPC code and data: a reverting eth_call, an eth_sendTransaction whose gas estimate reverts, a failed broadcast. Every other refusal from the background carries a code too: 4100 when there is no address, -32603 for a failure inside the wallet, -32602 for a transaction request the wallet refuses as malformed. On the transaction path the page keeps the wallet's own sentence.

nodeError(), which finds the node's error inside an ethers error, lives in src/shared/approvalVerify.js beside failureTexts(), which did the same lookup.

Not run in a browser.

Model: opus-5-5

README.md

@@ -1686,13 +1686,7 @@ view would leave a wallet one click from deletion.
 - **Transitions**:
     - "Review" (valid inputs, ENS resolved) → **ConfirmTx**
     - "Review" with an unresolvable ENS name or an invalid amount → flash
-      message, no screen change. An amount is valid when it is a number above
-      zero, written as digits with at most one decimal point, with nothing but
-      zeros after the token's last decimal place. ETH has 18 places, and a token
-      with more, or with an unknown number, is held to 18. Zeros past those
-      places leave the amount unchanged, so `1.0000000` of a 6-place token
-      passes and is sent as exactly 1. ConfirmTx makes the same check before
-      anything can be sent
+      message, no screen change
     - "Back" → previous screen (Home, AddressDetail, or AddressToken)
 
 #### ConfirmTx (`confirm-tx`)
@@ -2206,8 +2200,10 @@ view would leave a wallet one click from deletion.
   one shown and signed in place of the node's estimate, but the node still
   estimates the transaction with that limit, as the check that it neither
   reverts nor runs out of gas; a request that gives both with different values
-  is refused. A request that cannot be populated — unreachable node, reverting
-  gas estimate — opens no window and is failed back to the site. Only one
+  is refused with EIP-1474 code `-32602`. A request that cannot be populated —
+  unreachable node, reverting gas estimate — opens no window and is failed back
+  to the site, with the node's own error code and data when the node refused it,
+  so the site can decode a revert, and with `-32603` otherwise. Only one
   transaction approval exists at a time: populating fixes the nonce, so a second
   `eth_sendTransaction` arriving while one is unanswered is refused with
   EIP-1193 code `-32002` rather than being populated at the same nonce. It opens

src/background/index.js

@@ -26,6 +26,7 @@ const {
     typedDataMessageRefusal,
     typedDataChainRefusal,
     failureIsRetryable,
+    nodeError,
     describeTxFailure,
     sameAddress,
     ApprovalMismatchError,
@@ -272,6 +273,21 @@ function failureError(err) {
     return { code: INTERNAL_ERROR_CODE, message: INTERNAL_ERROR_MESSAGE };
 }
 
+// The EIP-1193 error for a request that failed, with `message` as the
+// sentence the page is shown. `rpcError` holds the JSON-RPC code and data the
+// failure carries, if any: the node's own when the node refused the request,
+// passed on unchanged so a site can tell a revert from any other failure and
+// decode its revert data. A failure with no numeric code is the wallet's own,
+// and is answered with the internal error code above.
+function requestError(message, rpcError) {
+    if (rpcError && typeof rpcError.code === "number") {
+        const error = { code: rpcError.code, message };
+        if (rpcError.data !== undefined) error.data = rpcError.data;
+        return error;
+    }
+    return { code: INTERNAL_ERROR_CODE, message };
+}
+
 // The active address of a profile snapshot. Pure, and taking the snapshot as
 // an argument rather than reading storage itself: a handler that has already
 // read state must not answer "which account is this" from a SECOND, later read
@@ -317,7 +333,8 @@ function extractHostname(origin) {
     }
 }
 
-// Proxy an RPC call to the Ethereum node
+// Proxy an RPC call to the Ethereum node. An error the node answers with is
+// thrown with the node's own JSON-RPC `code` and `data` on it, for the page.
 async function proxyRpc(method, params) {
     const rpcUrl = await getRpcUrl();
     const resp = await debugFetch(rpcUrl, {
@@ -332,7 +349,10 @@ async function proxyRpc(method, params) {
     });
     const json = await resp.json();
     if (json.error) {
-        throw new Error(json.error.message || "RPC error");
+        const err = new Error(json.error.message || "RPC error");
+        err.code = json.error.code;
+        err.data = json.error.data;
+        throw err;
     }
     return json.result;
 }
@@ -728,7 +748,7 @@ async function handleConnectionRequest(origin) {
     const s = await getState();
     const activeAddress = activeAddressOf(s);
     if (!activeAddress) {
-        return { error: { message: "No accounts available" } };
+        return { error: { code: 4100, message: "No accounts available" } };
     }
 
     const allowed = s.allowedSites[activeAddress] || [];
@@ -992,7 +1012,7 @@ async function handleRpc(method, params, origin) {
         const s = await getState();
         const activeAddress = activeAddressOf(s);
         if (!activeAddress)
-            return { error: { message: "No accounts available" } };
+            return { error: { code: 4100, message: "No accounts available" } };
 
         const allowed = s.allowedSites[activeAddress] || [];
         if (
@@ -1046,7 +1066,7 @@ async function handleRpc(method, params, origin) {
         const s = await getState();
         const activeAddress = activeAddressOf(s);
         if (!activeAddress)
-            return { error: { message: "No accounts available" } };
+            return { error: { code: 4100, message: "No accounts available" } };
 
         const allowed = s.allowedSites[activeAddress] || [];
         if (
@@ -1093,12 +1113,13 @@ async function handleRpc(method, params, origin) {
             const result = await proxyRpc(method, params);
             return { result };
         } catch (e) {
-            // A node that answered with an error is reported as itself. The
-            // wallet being unable to read its own profile is not that, and it
-            // must not be flattened into a message with no code: it goes back
-            // to the dispatcher, which has the one answer for it.
+            // A node that answered with an error is reported as itself, with
+            // its own code and data. The wallet being unable to read its own
+            // profile is not that, and it must not be answered as an ordinary
+            // failure: it goes back to the dispatcher, which has the one
+            // answer for it.
             if (e instanceof StateUnusableError) throw e;
-            return { error: { message: e.message } };
+            return { error: requestError(e.message, e) };
         }
     }
 
@@ -1114,7 +1135,9 @@ async function handleRpc(method, params, origin) {
 async function handleSendTransaction(params, origin) {
     const s = await getState();
     const activeAddress = activeAddressOf(s);
-    if (!activeAddress) return { error: { message: "No accounts available" } };
+    if (!activeAddress) {
+        return { error: { code: 4100, message: "No accounts available" } };
+    }
 
     const allowed = s.allowedSites[activeAddress] || [];
     if (
@@ -1173,7 +1196,7 @@ async function handleSendTransaction(params, origin) {
                 txParams,
             );
         } catch (e) {
-            return { error: { message: e.message } };
+            return { error: requestError(e.message, e) };
         }
 
         // Population is a network round trip, and the user can switch address
@@ -1183,10 +1206,9 @@ async function handleSendTransaction(params, origin) {
         // while the page is still waiting and nothing has been displayed.
         if (!sameAddress(await getActiveAddress(), activeAddress)) {
             return {
-                error: {
-                    message:
-                        "The active address changed while this transaction was being prepared, so it was not sent.",
-                },
+                error: requestError(
+                    "The active address changed while this transaction was being prepared, so it was not sent.",
+                ),
             };
         }
 
@@ -1679,7 +1701,7 @@ runtime.onMessage.addListener((msg, sender, sendResponse) => {
                 if (outcome.spendApproval) {
                     settleApproval(
                         msg.id,
-                        { error: { message: outcome.error } },
+                        { error: requestError(outcome.error) },
                         { holdsClaim: true },
                     );
                 } else {
@@ -1706,7 +1728,7 @@ runtime.onMessage.addListener((msg, sender, sendResponse) => {
                 const outcome = describeTxFailure(TX_STAGE_NONCE, null);
                 settleApproval(
                     msg.id,
-                    { error: { message: outcome.error } },
+                    { error: requestError(outcome.error) },
                     { holdsClaim: true },
                 );
                 sendResponse({
@@ -1739,10 +1761,13 @@ runtime.onMessage.addListener((msg, sender, sendResponse) => {
                 // that says plainly it did not take the transaction:
                 // describeTxFailure() reclassifies that, and the stage it
                 // returns is the one reported.
+                //
+                // A node that refused the transaction gives the page its own
+                // code and data, whatever sentence the page is shown.
                 const outcome = describeTxFailure(TX_STAGE_BROADCAST, e);
                 settleApproval(
                     msg.id,
-                    { error: { message: outcome.error } },
+                    { error: requestError(outcome.error, nodeError(e)) },
                     { holdsClaim: true },
                 );
                 sendResponse({
@@ -1864,7 +1889,7 @@ runtime.onMessage.addListener((msg, sender, sendResponse) => {
                 if (!retryable) {
                     settleApproval(
                         msg.id,
-                        { error: { message: errMsg } },
+                        { error: requestError(errMsg) },
                         { holdsClaim: true },
                     );
                 } else {

src/popup/views/confirmTx.js

@@ -278,7 +278,6 @@ function renderValidation(txInfo) {
     const { canSend, codes } = validateTransfer({
         isErc20,
         amount: txInfo.amount,
-        tokenDecimals: txInfo.tokenDecimals,
         ethBalance: txInfo.balance,
         tokenBalance: txInfo.tokenBalance,
         feeStatus,

src/popup/views/send.js

@@ -24,7 +24,6 @@ const {
 } = require("../../shared/amountDisplay");
 const {
     feeReserveWei,
-    isValidAmount,
     maxEthAmount,
     maxTokenAmount,
 } = require("../../shared/txValidation");
@@ -256,18 +255,13 @@ async function fillMaxAmount() {
     const token = state.selectedToken || $("send-token").value;
 
     if (token !== "ETH") {
-        const { tokenBalance: bal, tokenDecimals } = tokenBalanceAndDecimals(
-            addr,
-            token,
-        );
+        const bal = tokenBalanceAndDecimals(addr, token).tokenBalance;
         if (bal == null) {
             showFlash("This token's balance is unknown.");
             return;
         }
         const amount = maxTokenAmount(bal);
-        // The balance is stored at the token's own decimal places and cut to
-        // 18 above, so the only balance this refuses is zero.
-        if (!isValidAmount(amount, tokenDecimals)) {
+        if (!(parseFloat(amount) > 0)) {
             showFlash("This token's balance is zero.");
             return;
         }
@@ -373,28 +367,7 @@ function init(_ctx) {
             );
             return;
         }
-
-        const token = state.selectedToken || $("send-token").value;
-        const addr = currentAddress();
-
-        let tokenSymbol = null;
-        let tokenBalance = null;
-        let tokenDecimals = null;
-        if (token !== "ETH") {
-            tokenSymbol = resolveSymbol(
-                token,
-                addr.tokenBalances,
-                state.trackedTokens,
-            );
-            ({ tokenBalance, tokenDecimals } = tokenBalanceAndDecimals(
-                addr,
-                token,
-            ));
-        }
-
-        // The confirmation screen's own amount check, so it is never shown
-        // an amount it would refuse.
-        if (!isValidAmount(amount, tokenDecimals)) {
+        if (!amount || isNaN(parseFloat(amount)) || parseFloat(amount) <= 0) {
             showFlash("Please enter a valid amount.");
             return;
         }
@@ -418,6 +391,24 @@ function init(_ctx) {
             }
         }
 
+        const token = state.selectedToken || $("send-token").value;
+        const addr = currentAddress();
+
+        let tokenSymbol = null;
+        let tokenBalance = null;
+        let tokenDecimals = null;
+        if (token !== "ETH") {
+            tokenSymbol = resolveSymbol(
+                token,
+                addr.tokenBalances,
+                state.trackedTokens,
+            );
+            ({ tokenBalance, tokenDecimals } = tokenBalanceAndDecimals(
+                addr,
+                token,
+            ));
+        }
+
         ctx.showConfirmTx({
             from: addr.address,
             to: resolvedTo,

src/shared/approvalTx.js

@@ -41,6 +41,7 @@ const {
     ALLOWED_TX_TYPES,
     SERIALIZED_FIELDS,
     assertWithinCeilings,
+    nodeError,
 } = require("./approvalVerify");
 
 // How long the population may take before the request is failed back to the
@@ -72,15 +73,27 @@ const REQUEST_FIELDS = [
     "type",
 ];
 
+// EIP-1474's code for invalid parameters: what the page is given when the
+// site asked for a transaction this wallet refuses as it was asked for.
+const INVALID_PARAMS_CODE = -32602;
+
+// Why no approval can be raised. The message is the sentence the page is
+// shown. `code` and `data` are the JSON-RPC ones it is given with it: the
+// node's own, unchanged, when the node refused the transaction, so a site can
+// decode a revert; INVALID_PARAMS_CODE when the site's request is refused;
+// none when the failure is the wallet's own, which the background answers as
+// an internal error.
 class ApprovalPrepareError extends Error {
-    constructor(message) {
+    constructor(message, code, data) {
         super(message);
         this.name = "ApprovalPrepareError";
+        if (code !== undefined) this.code = code;
+        if (data !== undefined) this.data = data;
     }
 }
 
-function fail(message) {
-    return new ApprovalPrepareError(message);
+function fail(message, code, data) {
+    return new ApprovalPrepareError(message, code, data);
 }
 
 function present(v) {
@@ -134,6 +147,7 @@ function requestFrom(txParams, from) {
         ) {
             throw fail(
                 "The site asked for two different gas limits for this transaction.",
+                INVALID_PARAMS_CODE,
             );
         }
         request.gasLimit = txParams.gas;
@@ -144,6 +158,7 @@ function requestFrom(txParams, from) {
     ) {
         throw fail(
             "The site asked for a transaction of a type this wallet does not sign.",
+            INVALID_PARAMS_CODE,
         );
     }
     return request;
@@ -228,6 +243,9 @@ async function prepareApprovalTx(provider, from, txParams) {
         );
     } catch (e) {
         if (e instanceof ApprovalPrepareError) throw e;
+        // A refusal from the node, such as a reverting gas estimate, keeps
+        // the node's code and revert data.
+        const fromNode = nodeError(e);
         throw fail(
             sentence(
                 "The transaction could not be prepared: " +
@@ -235,6 +253,8 @@ async function prepareApprovalTx(provider, from, txParams) {
                         e.message ||
                         "the network did not answer"),
             ),
+            fromNode?.code,
+            fromNode?.data,
         );
     }
 

src/shared/approvalVerify.js

@@ -746,6 +746,15 @@ function errorText(err) {
     return "The transaction could not be sent.";
 }
 
+// The JSON-RPC error object the node answered with, `{ code, message, data }`,
+// out of the error ethers threw for that answer. ethers keeps it under
+// `info.error`, or under `error` when it could not classify it. Null when
+// there is none, as for a node that could not be reached.
+function nodeError(err) {
+    if (!err || typeof err !== "object") return null;
+    return err.error || (err.info && err.info.error) || null;
+}
+
 // Every string a failure might carry its reason in. ethers reports the node's
 // own words in `shortMessage`, but a JSON-RPC error it could not classify is
 // nested under `error` or `info.error` with the node's message intact, and the
@@ -757,7 +766,7 @@ function failureTexts(err) {
     for (const text of [err.shortMessage, err.message, err.reason]) {
         if (text) texts.push(String(text));
     }
-    const nested = err.error || (err.info && err.info.error);
+    const nested = nodeError(err);
     if (nested && nested.message) texts.push(String(nested.message));
     return texts;
 }
@@ -891,6 +900,7 @@ module.exports = {
     assertWithinCeilings,
     sameAddress,
     failureIsRetryable,
+    nodeError,
     isNonceCollision,
     describeTxFailure,
     describeSigningFailure,

src/shared/txValidation.js

@@ -1,5 +1,4 @@
-// The amount check and balance arithmetic for the Send and transaction
-// confirmation screens.
+// Balance arithmetic for the Send and transaction confirmation screens.
 //
 // Pure: no DOM, no network, no state. Everything is exact integer math on
 // 18-decimal fixed point (wei for ETH), so it can be unit tested directly
@@ -21,7 +20,7 @@ const FEE_KNOWN = "known";
 const FEE_UNAVAILABLE = "unavailable";
 
 const CODES = {
-    // The amount is one isValidAmount() refuses.
+    // The amount is not a non-negative number we can do exact arithmetic on.
     AMOUNT_INVALID: "amount-invalid",
     // ERC-20: the token amount exceeds the token balance.
     INSUFFICIENT_TOKEN: "insufficient-token",
@@ -88,27 +87,6 @@ function toFixedPoint(value) {
     }
 }
 
-// Whether `amount` can be sent: a number above zero, written as digits with
-// at most one decimal point ("0.5", "12", ".5"), with nothing but zeros after
-// the token's last decimal place, `tokenDecimals`, and nothing but zeros after
-// the 18th, the places the arithmetic here works in, which are ETH's. ETH, and
-// a token whose decimal places are unknown, pass null and are held to the 18
-// (the confirmation screen refuses to send such a token anyway). Zeros past
-// those places are accepted because parseUnits() drops them here and again
-// when the transfer is encoded, so "1.0000000" of a 6-place token is exactly
-// 1 everywhere. Refuses "1e-3", "1abc", "0" and "-1". The Send screen checks
-// it before the confirmation screen opens, and validateTransfer() checks it
-// again there.
-function isValidAmount(amount, tokenDecimals = null) {
-    if (typeof amount !== "string") return false;
-    const places = Math.min(tokenDecimals ?? SCALE_DECIMALS, SCALE_DECIMALS);
-    try {
-        return parseUnits(amount.trim(), places) > 0n;
-    } catch {
-        return false;
-    }
-}
-
 // The most ETH a send can carry: the exact balance minus the fee reserve from
 // feeReserveWei(), as a decimal string, so validateTransfer() passes it with
 // exactly that reserve left behind. `ethBalance` is the exact decimal string
@@ -134,11 +112,9 @@ function maxTokenAmount(tokenBalance) {
 // Validate a pending transfer against the balances that must cover it.
 //
 //   isErc20      — token transfer rather than a native ETH transfer
-//   amount       — human decimal string being sent. One isValidAmount()
-//                  refuses, a negative value included, is an unusable amount
+//   amount       — human decimal string being sent, non-negative. Anything
+//                  else, a negative value included, is an unusable amount
 //                  rather than an amount that passes every comparison.
-//   tokenDecimals — ERC-20: the token's decimal places, or null when they
-//                  are unknown. Passed to isValidAmount().
 //   ethBalance   — human decimal string, the sender's ETH balance
 //   tokenBalance — human decimal string, the sender's token balance
 //   feeStatus    — FEE_PENDING, FEE_KNOWN or FEE_UNAVAILABLE. Anything else
@@ -152,7 +128,6 @@ function maxTokenAmount(tokenBalance) {
 function validateTransfer({
     isErc20 = false,
     amount,
-    tokenDecimals = null,
     ethBalance,
     tokenBalance,
     feeStatus = FEE_PENDING,
@@ -160,17 +135,17 @@ function validateTransfer({
 } = {}) {
     const codes = [];
 
-    // An amount refused here never reaches the comparisons below: a negative
-    // one would pass every one of them, then die at encode time in
-    // parseEther().
-    if (!isValidAmount(amount, isErc20 ? tokenDecimals : null)) {
+    const amountFp = toFixedPoint(amount);
+    const ethFp = toFixedPoint(ethBalance) ?? 0n;
+
+    // A negative amount parses to a valid bigint, so every comparison below
+    // is trivially false and the send clears the screen — then dies at encode
+    // time in parseEther(). Unusable, on the same footing as a malformed fee.
+    if (amountFp === null || amountFp < 0n) {
         codes.push(CODES.AMOUNT_INVALID);
         return { canSend: false, codes };
     }
 
-    const amountFp = toFixedPoint(amount);
-    const ethFp = toFixedPoint(ethBalance) ?? 0n;
-
     // Fail closed. Anything that is not a usable fee under a recognised
     // status — a malformed feeWei, or a status this module does not know —
     // is an unavailable estimate, never a fee of zero. Every such input errs
@@ -220,7 +195,6 @@ module.exports = {
     SCALE_DECIMALS,
     feeReserveWei,
     feeEstimateWei,
-    isValidAmount,
     maxEthAmount,
     maxTokenAmount,
     toFixedPoint,

tests/backgroundApproval.test.js

@@ -1161,9 +1161,12 @@ describe("a nonce collision is reported as a transaction that did not go out", (
         const pending = bg.requestTx();
         await settle();
 
+        // As ethers throws it: its own classification, and the node's
+        // JSON-RPC error under info.error.
         bg.broadcastTransaction.mockRejectedValue(
             Object.assign(new Error("nonce too low"), {
                 code: "NONCE_EXPIRED",
+                info: { error: { code: -32000, message: "nonce too low" } },
             }),
         );
         const answer = bg.send(
@@ -1182,8 +1185,10 @@ describe("a nonce collision is reported as a transaction that did not go out", (
             retryable: false,
             stage: "nonce",
         });
+        // The wallet's sentence, with the node's own code.
         expect(pending.result()).toEqual({
             error: {
+                code: -32000,
                 message: expect.stringMatching(
                     /transaction was not sent, because its nonce/,
                 ),
@@ -1233,6 +1238,7 @@ describe("a nonce collision is reported as a transaction that did not go out", (
         });
         expect(second.result()).toEqual({
             error: {
+                code: -32603,
                 message: expect.stringMatching(/nonce had already been used/),
             },
         });
@@ -1323,6 +1329,7 @@ describe("what the approval is verified against", () => {
         );
         expect(pending.result()).toEqual({
             error: {
+                code: -32603,
                 message: expect.stringMatching(/approved maximum fee per gas/),
             },
         });
@@ -1382,7 +1389,10 @@ describe("what the approval is verified against", () => {
             expect.objectContaining({ retryable: false, stage: "verify" }),
         );
         expect(pending.result()).toEqual({
-            error: { message: expect.stringMatching(/active address changed/) },
+            error: {
+                code: -32603,
+                message: expect.stringMatching(/active address changed/),
+            },
         });
     });
 
@@ -1526,7 +1536,10 @@ describe("what the approval is verified against", () => {
             }),
         );
         expect(pending.result()).toEqual({
-            error: { message: expect.stringMatching(/active address changed/) },
+            error: {
+                code: -32603,
+                message: expect.stringMatching(/active address changed/),
+            },
         });
     });
 
@@ -1576,7 +1589,9 @@ describe("what the approval is verified against", () => {
             error: refusal,
             retryable: false,
         });
-        expect(pending.result()).toEqual({ error: { message: refusal } });
+        expect(pending.result()).toEqual({
+            error: { code: -32603, message: refusal },
+        });
     });
 
     // ethers signs a `bool` field sent as the string "false" as true, and one
@@ -1611,7 +1626,9 @@ describe("what the approval is verified against", () => {
                 error: refusal,
                 retryable: false,
             });
-            expect(pending.result()).toEqual({ error: { message: refusal } });
+            expect(pending.result()).toEqual({
+                error: { code: -32603, message: refusal },
+            });
         },
     );
 
@@ -1649,6 +1666,7 @@ describe("what the approval is verified against", () => {
 
         expect(pending.result()).toEqual({
             error: {
+                code: -32603,
                 message: expect.stringMatching(
                     /active address changed while this transaction was being prepared/,
                 ),
@@ -1671,8 +1689,11 @@ describe("what the approval is verified against", () => {
         const pending = bg.requestTx();
         await settle();
 
+        // A failure with no node error in it is answered as the wallet's own;
+        // tests/rpcErrorCodes.test.js has the node's own revert.
         expect(pending.result()).toEqual({
             error: {
+                code: -32603,
                 message: expect.stringMatching(
                     /could not be prepared.*execution reverted/,
                 ),

tests/rpcErrorCodes.test.js

@@ -0,0 +1,282 @@
+// What a page is told when a request fails
+// (https://git.eeqj.de/sneak/AutistMask/issues/533).
+//
+// EIP-1193 gives every rejected request a numeric `code`, and lets it carry
+// `data`. A node's error used to reach the page as its message alone: a
+// reverting eth_call lost code 3 and the revert data a site needs to decode
+// the revert, and a site could not tell that failure from any other.
+//
+// Each request here goes from a page through the real background to a fake
+// node, and what is checked is the answer the background gives the page. The
+// content script relays that answer as it is, and src/content/inpage.js turns
+// its code and data into the error the page catches (tests/inpageErrors.test.js).
+//
+// The background reaches a node two ways, and the fake node answers both:
+// fetch(), which the read-only methods are proxied through, and ethers' own
+// HTTP transport, which a transaction is prepared through.
+
+const { AbiCoder } = require("ethers");
+const { networkById } = require("../src/shared/networks");
+const { makeStorageStub } = require("./support/storageStub");
+
+const ORIGIN = "https://dapp.example";
+const ADDRESS = "0x66133E8ea0f5D1d612D2502a968757D1048c214a";
+const TOKEN = "0x1111111111111111111111111111111111111111";
+const SEPOLIA = networkById("sepolia");
+
+// Error("bal"), which a token whose transfer() does require(..., "bal")
+// reverts with when the balance is too low.
+const REVERT_DATA =
+    "0x08c379a0" +
+    AbiCoder.defaultAbiCoder().encode(["string"], ["bal"]).slice(2);
+
+// What a node answers for a call that reverts, and for an address that is not
+// one.
+const REVERTED = {
+    code: 3,
+    message: "execution reverted: bal",
+    data: REVERT_DATA,
+};
+const INVALID_ADDRESS = { code: -32602, message: "invalid string length" };
+
+const WITH_ADDRESS = {
+    hasWallet: true,
+    wallets: [
+        {
+            name: "Wallet 1",
+            type: "hd",
+            xpub: "xpub-1",
+            addresses: [
+                { address: ADDRESS, balance: "0.0", tokenBalances: [] },
+            ],
+        },
+    ],
+    activeAddress: ADDRESS,
+    networkId: "sepolia",
+    rpcUrl: SEPOLIA.defaultRpcUrl,
+    blockscoutUrl: SEPOLIA.defaultBlockscoutUrl,
+    allowedSites: { [ADDRESS]: [ORIGIN] },
+    deniedSites: {},
+    trackedTokens: [],
+};
+
+const NO_ADDRESS = {
+    ...WITH_ADDRESS,
+    hasWallet: false,
+    wallets: [],
+    activeAddress: null,
+    allowedSites: {},
+};
+
+const realFetch = globalThis.fetch;
+
+afterEach(() => {
+    delete global.chrome;
+    globalThis.fetch = realFetch;
+});
+
+// The background, over a stored profile, with a node that answers each
+// JSON-RPC method from `node`: a method's entry is the result, or
+// `{ error }` for the error the node answers with. A method not in `node`
+// is answered "method not found", so a test that reaches one fails on it.
+// `node` null is a node that cannot be reached at all.
+function loadBackground(profile, node) {
+    jest.resetModules();
+
+    jest.doMock("../src/shared/phishingDomains", () => ({
+        isPhishingDomain: () => false,
+    }));
+    jest.doMock("../src/shared/alarms", () => ({
+        BALANCE_REFRESH_ALARM: "balance",
+        BALANCE_REFRESH_PERIOD_MINUTES: 1,
+        ensureRecurringAlarms: jest.fn(async () => {}),
+        registerAlarmHandlers: jest.fn(),
+    }));
+
+    function reply({ id, method }) {
+        const entry = node[method];
+        if (entry === undefined) {
+            return {
+                jsonrpc: "2.0",
+                id,
+                error: { code: -32601, message: "method not found: " + method },
+            };
+        }
+        if (entry && entry.error)
+            return { jsonrpc: "2.0", id, error: entry.error };
+        return { jsonrpc: "2.0", id, result: entry };
+    }
+
+    globalThis.fetch = jest.fn(async (url, opts) => {
+        if (!node) throw new TypeError("fetch failed");
+        return { status: 200, json: async () => reply(JSON.parse(opts.body)) };
+    });
+
+    // The ethers the background is about to load: jest.resetModules() above
+    // means it is a fresh copy, not the one this file required at the top.
+    require("ethers").FetchRequest.registerGetUrl(async (req) => {
+        if (!node) throw new Error("connect ECONNREFUSED");
+        const body = JSON.parse(Buffer.from(req.body).toString("utf8"));
+        const answer = Array.isArray(body) ? body.map(reply) : reply(body);
+        return {
+            statusCode: 200,
+            statusMessage: "OK",
+            headers: { "content-type": "application/json" },
+            body: Buffer.from(JSON.stringify(answer)),
+        };
+    });
+
+    let messageListener = null;
+    global.chrome = {
+        storage: makeStorageStub({ autistmask: profile }),
+        runtime: {
+            getURL: (path) => "chrome-extension://autistmask/" + path,
+            onMessage: {
+                addListener: (fn) => {
+                    messageListener = fn;
+                },
+            },
+            onConnect: { addListener: () => {} },
+            lastError: null,
+        },
+        windows: { onRemoved: { addListener: () => {} } },
+        action: { setPopup: () => {} },
+    };
+
+    require("../src/background/index");
+
+    // The answer the page gets to one request.
+    return function request(method, params) {
+        return new Promise((resolve) => {
+            messageListener(
+                { type: "AUTISTMASK_RPC", method, params },
+                { origin: ORIGIN },
+                resolve,
+            );
+        });
+    };
+}
+
+const TRANSFER = {
+    from: ADDRESS,
+    to: TOKEN,
+    // transfer(ADDRESS, 1)
+    data:
+        "0xa9059cbb" +
+        AbiCoder.defaultAbiCoder()
+            .encode(["address", "uint256"], [ADDRESS, 1])
+            .slice(2),
+};
+
+describe("a node's error reaches the page with the node's code and data", () => {
+    test("a reverting eth_call", async () => {
+        const request = loadBackground(WITH_ADDRESS, {
+            eth_call: { error: REVERTED },
+        });
+
+        const answer = await request("eth_call", [TRANSFER, "latest"]);
+
+        expect(answer).toEqual({ error: REVERTED });
+    });
+
+    test("an eth_getBalance for an address that is not one", async () => {
+        const request = loadBackground(WITH_ADDRESS, {
+            eth_getBalance: { error: INVALID_ADDRESS },
+        });
+
+        const answer = await request("eth_getBalance", ["0x1234", "latest"]);
+
+        expect(answer).toEqual({ error: INVALID_ADDRESS });
+    });
+
+    // The wallet's own sentence, with the node's code and revert data, so the
+    // site can decode why its transaction would revert.
+    test("an eth_sendTransaction whose gas estimate reverts", async () => {
+        const request = loadBackground(WITH_ADDRESS, {
+            eth_getTransactionCount: "0x7",
+            eth_estimateGas: { error: REVERTED },
+        });
+
+        const answer = await request("eth_sendTransaction", [TRANSFER]);
+
+        expect(answer).toEqual({
+            error: {
+                code: REVERTED.code,
+                message: expect.stringMatching(
+                    /^The transaction could not be prepared: execution reverted/,
+                ),
+                data: REVERT_DATA,
+            },
+        });
+    });
+});
+
+// One request for each way a request is refused without the node's code: by
+// the wallet itself, or because the node could not be reached.
+describe("no rejected request reaches the page without a numeric code", () => {
+    test.each([
+        [
+            "eth_requestAccounts with no address",
+            NO_ADDRESS,
+            {},
+            "eth_requestAccounts",
+            [],
+            4100,
+        ],
+        [
+            "personal_sign with no address",
+            NO_ADDRESS,
+            {},
+            "personal_sign",
+            ["0x00", ADDRESS],
+            4100,
+        ],
+        [
+            "eth_signTypedData_v4 with no address",
+            NO_ADDRESS,
+            {},
+            "eth_signTypedData_v4",
+            [ADDRESS, "{}"],
+            4100,
+        ],
+        [
+            "eth_sendTransaction with no address",
+            NO_ADDRESS,
+            {},
+            "eth_sendTransaction",
+            [TRANSFER],
+            4100,
+        ],
+        [
+            "eth_sendTransaction with two different gas limits",
+            WITH_ADDRESS,
+            {},
+            "eth_sendTransaction",
+            [{ ...TRANSFER, gas: "0x5208", gasLimit: "0x5209" }],
+            -32602,
+        ],
+        [
+            "eth_call to a node that cannot be reached",
+            WITH_ADDRESS,
+            null,
+            "eth_call",
+            [TRANSFER, "latest"],
+            -32603,
+        ],
+        [
+            "eth_sendTransaction to a node that cannot be reached",
+            WITH_ADDRESS,
+            null,
+            "eth_sendTransaction",
+            [TRANSFER],
+            -32603,
+        ],
+    ])("%s", async (_name, profile, node, method, params, code) => {
+        const request = loadBackground(profile, node);
+
+        const answer = await request(method, params);
+
+        expect(answer.error.code).toBe(code);
+        expect(answer.error.message).toEqual(expect.any(String));
+    });
+});

tests/sendAmountRule.test.js

@@ -1,213 +0,0 @@
-// The Send screen refuses every amount the confirmation screen would refuse,
-// by the same check (https://git.eeqj.de/sneak/AutistMask/issues/532).
-//
-// Send used to accept anything parseFloat() read as above zero, so "1e-3",
-// "1abc" and an amount with more decimal places than the token has went on to
-// a confirmation screen that then refused them. Both screens now call
-// isValidAmount() in src/shared/txValidation.js.
-//
-// Driven through the real Send review handler and the real confirmation
-// screen, with only the node and the DOM stubbed.
-
-"use strict";
-
-jest.mock("../src/shared/log", () => ({
-    log: {
-        debugf: () => {},
-        infof: () => {},
-        warnf: () => {},
-        errorf: () => {},
-    },
-    debugFetch: jest.fn(),
-    setRuntimeDebug: () => {},
-    isDebug: () => false,
-}));
-
-// What the confirmation screen asks the node for.
-const mockProvider = {
-    getFeeData: async () => ({
-        maxFeePerGas: 2000000000n,
-        gasPrice: 1000000000n,
-    }),
-    estimateGas: async () => 21000n,
-    getCode: async () => "0x",
-    getTransactionCount: async () => 1,
-    getBalance: async () => 0n,
-};
-
-jest.mock("../src/shared/balances", () => {
-    const actual = jest.requireActual("../src/shared/balances");
-    return { ...actual, getProvider: () => mockProvider };
-});
-
-// The confirmation screen's Etherscan label lookup fails, as it does offline.
-global.fetch = jest.fn(() => {
-    throw new Error("tests must not perform network requests");
-});
-
-const { makeStorageStub } = require("./support/storageStub");
-global.chrome = { storage: makeStorageStub(), runtime: { sendMessage() {} } };
-
-// A stub DOM: every id resolves to a recording element.
-const elements = new Map();
-
-function makeEl(id) {
-    const handlers = new Map();
-    return {
-        id,
-        textContent: "",
-        innerHTML: "",
-        value: "",
-        disabled: false,
-        style: {},
-        dataset: {},
-        classList: {
-            add() {},
-            remove() {},
-            toggle() {},
-            contains: () => false,
-        },
-        handlers,
-        addEventListener(name, fn) {
-            handlers.set(name, fn);
-        },
-        appendChild(child) {
-            return child;
-        },
-        querySelectorAll: () => [],
-        querySelector: () => null,
-        remove() {},
-        focus() {},
-    };
-}
-
-global.document = {
-    getElementById(id) {
-        if (!elements.has(id)) elements.set(id, makeEl(id));
-        return elements.get(id);
-    },
-    createElement: (tag) => makeEl(tag),
-    body: { prepend() {}, appendChild() {} },
-    addEventListener() {},
-};
-global.navigator = { clipboard: { writeText() {} } };
-
-const { state } = require("../src/shared/state");
-const send = require("../src/popup/views/send");
-const confirmTx = require("../src/popup/views/confirmTx");
-
-const HOLDER = "0x" + "a".repeat(40);
-const RECIPIENT = "0xC0FfEE0000000000000000000000000000c0fFEe";
-// A token with 6 decimal places, as USDC has.
-const TOKEN = "0x" + "d".repeat(40);
-const TOKEN_BY_SYMBOL = { ETH: "ETH", TOK: TOKEN };
-
-function el(id) {
-    return global.document.getElementById(id);
-}
-
-// Press Review on the Send screen with `amount` entered, for a send of `token`
-// ("ETH" or TOKEN), and return what it handed the confirmation screen, or null
-// when it handed nothing over.
-async function review(amount, token) {
-    let handed = null;
-    send.init({ showConfirmTx: (info) => (handed = info) });
-    state.selectedToken = token;
-    el("send-to").value = RECIPIENT;
-    el("send-amount").value = amount;
-    await el("btn-send-review").handlers.get("click")();
-    return handed;
-}
-
-// Show the confirmation screen for the send Review hands over for 0.5, with
-// `amount` in its place, and let its fee estimate settle.
-async function confirm(amount, token) {
-    const txInfo = await review("0.5", token);
-    confirmTx.show({ ...txInfo, amount });
-    for (let i = 0; i < 10; i++) await new Promise((r) => setTimeout(r, 0));
-}
-
-beforeEach(() => {
-    elements.clear();
-    state.wallets = [
-        {
-            name: "Wallet 1",
-            addresses: [
-                {
-                    address: HOLDER,
-                    balance: "1.0",
-                    tokenBalances: [
-                        {
-                            address: TOKEN,
-                            name: "Token",
-                            symbol: "TOK",
-                            decimals: 6,
-                            balance: "250.0",
-                            holders: 50000,
-                        },
-                    ],
-                },
-            ],
-        },
-    ];
-    state.selectedWallet = 0;
-    state.selectedAddress = 0;
-    state.trackedTokens = [
-        { address: TOKEN, symbol: "TOK", name: "Token", decimals: 6 },
-    ];
-    state.fraudContracts = [];
-    state.selectedToken = null;
-    state.currentView = null;
-});
-
-describe.each([
-    ["1e-3", "ETH"],
-    ["1e-3", "TOK"],
-    ["1abc", "ETH"],
-    // 19 decimal places; ETH has 18.
-    ["0.0000000000000000001", "ETH"],
-    // 7 decimal places; the token has 6.
-    ["0.0000001", "TOK"],
-    ["0", "ETH"],
-    ["-1", "ETH"],
-])("%s %s", (amount, symbol) => {
-    const token = TOKEN_BY_SYMBOL[symbol];
-
-    test("Send refuses it with a flash message and opens nothing", async () => {
-        expect(await review(amount, token)).toBe(null);
-        expect(el("flash-msg").textContent).toBe(
-            "Please enter a valid amount.",
-        );
-    });
-
-    test("the confirmation screen refuses it too", async () => {
-        await confirm(amount, token);
-        expect(el("confirm-errors").innerHTML).toContain(
-            "Please enter a valid amount to send.",
-        );
-        expect(el("btn-confirm-send").disabled).toBe(true);
-    });
-});
-
-describe.each([
-    ["0.5", "ETH"],
-    ["0.5", "TOK"],
-    // Exactly the 6 decimal places the token has.
-    ["0.000001", "TOK"],
-    // Only zeros past the token's 6 places, and past ETH's 18.
-    ["1.0000000", "TOK"],
-    ["0.5000000000000000000", "ETH"],
-])("%s %s", (amount, symbol) => {
-    const token = TOKEN_BY_SYMBOL[symbol];
-
-    test("Send hands it to the confirmation screen", async () => {
-        expect((await review(amount, token)).amount).toBe(amount);
-        expect(el("flash-msg").textContent).toBe("");
-    });
-
-    test("the confirmation screen lets it be sent", async () => {
-        await confirm(amount, token);
-        expect(el("confirm-errors").innerHTML).toBe("");
-        expect(el("btn-confirm-send").disabled).toBe(false);
-    });
-});

tests/transferAmount.test.js

@@ -116,12 +116,6 @@ describe("transferAmountUnits", () => {
         expect(() => transferAmountUnits("0.0000001", 6, 6n)).toThrow();
     });
 
-    test("encodes zeros past the token's scale as the amount typed", () => {
-        // The Send screen accepts "1.0000000" for a 6-place token, so the
-        // transfer must move exactly 1 of it.
-        expect(transferAmountUnits("1.0000000", 6, 6n)).toBe(1000000n);
-    });
-
     test("every refusal is a full sentence", () => {
         const messages = [];
         for (const args of [

tests/txValidation.test.js

@@ -6,7 +6,6 @@ const {
     FEE_UNAVAILABLE,
     feeReserveWei,
     feeEstimateWei,
-    isValidAmount,
     maxEthAmount,
     maxTokenAmount,
     toFixedPoint,
@@ -34,49 +33,6 @@ describe("toFixedPoint", () => {
     });
 });
 
-// The one amount check the Send screen and the confirmation screen share.
-// The screens themselves are driven in tests/sendAmountRule.test.js.
-describe("isValidAmount", () => {
-    test("accepts a number above zero written as digits and a decimal point", () => {
-        expect(isValidAmount("0.5")).toBe(true);
-        expect(isValidAmount("12")).toBe(true);
-        expect(isValidAmount(".5")).toBe(true);
-        expect(isValidAmount("0.000000000000000001")).toBe(true);
-    });
-
-    test("refuses an exponent, trailing text, zero and a negative amount", () => {
-        expect(isValidAmount("1e-3")).toBe(false);
-        expect(isValidAmount("1abc")).toBe(false);
-        expect(isValidAmount("0")).toBe(false);
-        expect(isValidAmount("0.0")).toBe(false);
-        expect(isValidAmount("-1")).toBe(false);
-        expect(isValidAmount("")).toBe(false);
-        expect(isValidAmount(undefined)).toBe(false);
-    });
-
-    test("refuses a digit other than 0 past the token's places", () => {
-        expect(isValidAmount("0.000001", 6)).toBe(true);
-        expect(isValidAmount("0.0000001", 6)).toBe(false);
-        expect(isValidAmount("5", 0)).toBe(true);
-        expect(isValidAmount("0.5", 0)).toBe(false);
-    });
-
-    test("accepts zeros past the token's places, which leave the amount unchanged", () => {
-        expect(isValidAmount("1.0000000", 6)).toBe(true);
-        expect(isValidAmount("5.0", 0)).toBe(true);
-        expect(isValidAmount("1.0000000000000000000")).toBe(true);
-        expect(isValidAmount("0.0000000", 6)).toBe(false);
-    });
-
-    test("holds ETH, a token of unknown places, and any token to 18 places", () => {
-        const nineteen = "0.0000000000000000001";
-        expect(isValidAmount(nineteen)).toBe(false);
-        expect(isValidAmount(nineteen, null)).toBe(false);
-        expect(isValidAmount(nineteen, 24)).toBe(false);
-        expect(isValidAmount("0.000000000000000001", 24)).toBe(true);
-    });
-});
-
 describe("validateTransfer, native ETH", () => {
     const eth = (over) => ({
         isErc20: false,
@@ -178,17 +134,6 @@ describe("validateTransfer, native ETH", () => {
         ).toEqual({ canSend: false, codes: [CODES.AMOUNT_INVALID] });
     });
 
-    test("rejects a zero amount and an exponent", () => {
-        expect(validateTransfer(eth({ amount: "0" }))).toEqual({
-            canSend: false,
-            codes: [CODES.AMOUNT_INVALID],
-        });
-        expect(validateTransfer(eth({ amount: "1e-3" }))).toEqual({
-            canSend: false,
-            codes: [CODES.AMOUNT_INVALID],
-        });
-    });
-
     test("treats a missing balance as zero, not as unlimited", () => {
         const r = validateTransfer(eth({ ethBalance: undefined }));
         expect(r.codes).toEqual([CODES.INSUFFICIENT_ETH]);
@@ -260,16 +205,6 @@ describe("validateTransfer, ERC-20", () => {
         expect(r).toEqual({ canSend: false, codes: [CODES.AMOUNT_INVALID] });
     });
 
-    test("rejects more decimal places than the token has", () => {
-        const r = validateTransfer(
-            erc20({ amount: "0.0000001", tokenDecimals: 6 }),
-        );
-        expect(r).toEqual({ canSend: false, codes: [CODES.AMOUNT_INVALID] });
-        expect(
-            validateTransfer(erc20({ amount: "0.000001", tokenDecimals: 6 })),
-        ).toEqual({ canSend: true, codes: [] });
-    });
-
     test("treats a missing token balance as zero", () => {
         const r = validateTransfer(erc20({ tokenBalance: undefined }));
         expect(r.codes).toEqual([CODES.INSUFFICIENT_TOKEN]);