fix: closing a transaction or signature approval window leaves the request pending (closes #673)

The browser can close the approval window when the user clicks away from it,
for example to copy the password from a password manager. Closing it used to
reject the request with 4001. Now the request stays pending and the site gets
no answer. Until it is answered, the toolbar popup opens the oldest such
approval. The toolbar popup skips an approval while its transaction is being
sent or its signature checked. A worker that starts holds no approvals, so it
points the toolbar popup back at the wallet.

Reject now closes its window only after the background has the rejection. A
rejection the background refuses leaves the window open with the background's
message.

Site-connection and network-switch windows still reject the request when
closed.

Model: opus-5-5

tests/approvalWindow.test.js

@@ -12,6 +12,7 @@ const {
     cleanupPopup,
     settle,
     unversionedValidProfile,
+    ADDRESS,
 } = require("./support/popupBoot");
 
 afterEach(cleanupPopup);
@@ -174,3 +175,136 @@ test("a connection prompt in the toolbar popup leaves the browser window alone",
     expect(windows.updates).toEqual([]);
     expect(env.pageErrors).toEqual([]);
 });
+
+// Each row holds a transaction or signature approval as the background
+// describes it, plus the element ids of the screen that shows it. `refusal` is
+// the message the background refuses a Reject with.
+const TX_AND_SIGN_APPROVALS = [
+    {
+        kind: "transaction",
+        view: "approve-tx",
+        reject: "btn-reject-tx",
+        error: "approve-tx-error",
+        type: "AUTISTMASK_TX_RESPONSE",
+        refusal: "This transaction is already being sent.",
+        approval: {
+            type: "tx",
+            approvedFrom: ADDRESS,
+            approvedTx: {
+                chainId: 1,
+                to: ADDRESS,
+                value: "0",
+                data: "0x",
+                gasLimit: "21000",
+                maxFeePerGas: "1000000000",
+                maxPriorityFeePerGas: "1000000000",
+                nonce: 0,
+            },
+        },
+    },
+    {
+        kind: "signature",
+        view: "approve-sign",
+        reject: "btn-reject-sign",
+        error: "approve-sign-error",
+        type: "AUTISTMASK_SIGN_RESPONSE",
+        refusal: "This request is already being signed.",
+        approval: {
+            type: "sign",
+            approvedFrom: ADDRESS,
+            signParams: {
+                method: "personal_sign",
+                message: "0x48656c6c6f",
+                from: ADDRESS,
+            },
+        },
+    },
+];
+
+// A closed transaction or signature window leaves its request pending
+// (https://git.eeqj.de/sneak/AutistMask/issues/673). So Reject closes the
+// window only once the background has the rejection. A message sent as the
+// window closes can be lost, and the request would stay pending although the
+// user rejected it.
+test.each(TX_AND_SIGN_APPROVALS)(
+    "Reject on a $kind approval closes the window only once the background has answered",
+    async ({ view, reject, type, approval }) => {
+        let describeApproval = null;
+        let answerReject = null;
+        const sent = [];
+        const env = await bootPopup(unversionedValidProfile(), {
+            search: "?approval=approval-1",
+            runtime: {
+                connect: () => ({ postMessage: () => {} }),
+                sendMessage: (msg, reply) => {
+                    if (msg.type === "AUTISTMASK_GET_APPROVAL") {
+                        describeApproval = reply;
+                    }
+                    if (msg.type === type) {
+                        sent.push(msg);
+                        answerReject = reply;
+                    }
+                },
+            },
+        });
+        describeApproval({
+            ...approval,
+            origin: "https://dapp.example",
+            isPhishingDomain: false,
+        });
+        await settle();
+        expect(env.visibleViews()).toEqual([view]);
+        const close = jest.fn();
+        globalThis.window.close = close;
+
+        const clicked = env.click(reject);
+        await settle();
+        expect(sent).toEqual([{ type, id: "approval-1", approved: false }]);
+        expect(close).not.toHaveBeenCalled();
+
+        answerReject(null);
+        await clicked;
+        expect(close).toHaveBeenCalledTimes(1);
+        expect(env.pageErrors).toEqual([]);
+    },
+);
+
+// After Confirm or Sign, the background refuses a Reject while the transaction
+// is being sent or the signature checked. The request is not rejected then, so
+// the window stays open and shows the background's message.
+test.each(TX_AND_SIGN_APPROVALS)(
+    "Reject on a $kind approval that the background refuses shows the background's message and keeps the window open",
+    async ({ view, reject, error, type, refusal, approval }) => {
+        let describeApproval = null;
+        let answerReject = null;
+        const env = await bootPopup(unversionedValidProfile(), {
+            search: "?approval=approval-1",
+            runtime: {
+                connect: () => ({ postMessage: () => {} }),
+                sendMessage: (msg, reply) => {
+                    if (msg.type === "AUTISTMASK_GET_APPROVAL") {
+                        describeApproval = reply;
+                    }
+                    if (msg.type === type) answerReject = reply;
+                },
+            },
+        });
+        describeApproval({
+            ...approval,
+            origin: "https://dapp.example",
+            isPhishingDomain: false,
+        });
+        await settle();
+        const close = jest.fn();
+        globalThis.window.close = close;
+
+        const clicked = env.click(reject);
+        await settle();
+        answerReject({ error: refusal, retryable: false });
+        await clicked;
+        expect(close).not.toHaveBeenCalled();
+        expect(env.visibleViews()).toEqual([view]);
+        expect(env.text(error)).toBe(refusal);
+        expect(env.pageErrors).toEqual([]);
+    },
+);