fix: open an approval window while another one has focus (closes #290)

The background centred each approval window on the last focused window,
which could be an earlier approval window still open; headless Chrome
reports one as 1280x720, the browser refused the resulting position, and
the request failed with no window. It now centres only on a browser
window, and when the browser refuses a position it asks again without one.

In the Chrome suite a test could raise its prompt while the previous
test's window was still closing. After a passed test the runner now gives
approval windows five seconds to close and fails the test if one is still
open; after a failed test it closes them.

Model: opus-5-5

tests/e2e/run.js

@@ -2676,7 +2676,9 @@ function dappMessages(page, type) {
 
 // The approval window the background opened. Approvals are raised from an
 // RPC call rather than from a user gesture, so the extension opens a real
-// popup window for them; it is an ordinary page in this context.
+// popup window for them; it is an ordinary page in this context. It is the
+// first one found: no test starts with an approval window open (see main()),
+// so within a test it can only be this test's.
 async function waitForApprovalWindow(ctx, timeout = 30000) {
     const deadline = Date.now() + timeout;
     for (;;) {
@@ -3633,6 +3635,55 @@ test("eth_sendTransaction rejected broadcasts nothing (#183)", async (env) => {
     );
 });
 
+// The extension used to centre every approval window on the last focused
+// window. Centred on another approval window, the new one landed where the
+// browser refused to create it, and the request failed with no window at all
+// (https://git.eeqj.de/sneak/AutistMask/issues/290).
+test("a prompt raised while another approval window has focus opens its own (#290)", async (env) => {
+    await startRequest(env.dapp, "focus-sign", "personal_sign", [
+        SIGN_HEX,
+        env.expectedAddress,
+    ]);
+    const signWindow = await waitForApprovalWindow(env.ctx);
+    await visible(signWindow, "#view-approve-sign");
+    await signWindow.bringToFront();
+    const focused = await env.page.evaluate(
+        () =>
+            new Promise((resolve) => {
+                chrome.windows.getLastFocused((w) => resolve(w.type));
+            }),
+    );
+    assert(
+        focused === "popup",
+        "the sign window does not have focus, so this proves nothing: the " +
+            "last focused window is a " +
+            focused,
+    );
+
+    const opened = env.ctx.waitForEvent("page");
+    await startRequest(env.dapp, "focus-tx", "eth_sendTransaction", [
+        {
+            from: env.expectedAddress,
+            to: STUB_COUNTERPARTY,
+            value: toQuantity(TX_VALUE_WEI),
+            data: TX_DATA,
+        },
+    ]);
+    const txWindow = await opened.catch(async () => {
+        const outcome = await settleRequest(env.dapp, "focus-tx", 1000);
+        throw new Error(
+            "the extension opened no window for the transaction: " +
+                JSON.stringify(outcome),
+        );
+    });
+    await visible(txWindow, "#view-approve-tx");
+
+    // Closing a window is refusing its prompt, so both answer 4001.
+    await closeApprovalPages(env.ctx);
+    await assertUserRejection(env.dapp, "focus-tx", "the transaction prompt");
+    await assertUserRejection(env.dapp, "focus-sign", "the sign prompt");
+});
+
 // The closing pass over both boundaries at once. Every message the section
 // put on either channel is re-read here and required to be free of the
 // password — and required to be there at all, method by method, so the
@@ -4002,6 +4053,36 @@ async function main() {
             failure = e.message;
         }
 
+        // No test starts with an approval window open. One that closes itself,
+        // after a signature or on Reject, can still be closing when the next
+        // test raises its prompt, and waitForApprovalWindow() would take it
+        // for the new one. After a test that passed, its windows get five
+        // seconds to close, and one still open then fails the test: it should
+        // have closed itself, and closing it here unreported would hide that.
+        // After a test that already failed, they are closed unreported, so
+        // that a prompt it left unanswered does not refuse the next one from
+        // its site.
+        if (!failure) {
+            const deadline = Date.now() + 5000;
+            let open;
+            for (;;) {
+                open = env.ctx
+                    .pages()
+                    .filter(
+                        (p) => !p.isClosed() && p.url().includes("?approval="),
+                    );
+                if (open.length === 0 || Date.now() > deadline) break;
+                await sleep(50);
+            }
+            if (open.length > 0) {
+                failure =
+                    "an approval window was still open 5000ms after the " +
+                    "test: " +
+                    open.map((p) => p.url()).join(", ");
+            }
+        }
+        await closeApprovalPages(env.ctx);
+
         // Any uncaught page error, console.error or unstubbed request
         // fails the test that provoked it, whether or not its assertions
         // passed. This is the mechanism that caught #150.