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/backgroundApproval.test.js

@@ -267,9 +267,22 @@ function loadBackground(options) {
             lastError: null,
         },
         windows: {
-            getLastFocused: (cb) => cb(null),
+            getLastFocused: (cb) => cb(opts.lastFocused || null),
             create: (options2, cb) => {
-                created.push(options2);
+                // A copy, as the browser takes it at the call: the background
+                // reuses the object when it asks a second time.
+                created.push({ ...options2 });
+                // A browser that refuses any position it is given, as Chrome
+                // does for one it judges too far off screen.
+                if (opts.refusePosition && options2.left !== undefined) {
+                    global.chrome.runtime.lastError = {
+                        message:
+                            "Invalid value for bounds. Bounds must be at least 50% within visible screen space.",
+                    };
+                    cb(undefined);
+                    global.chrome.runtime.lastError = null;
+                    return;
+                }
                 // A browser that answers with no window at all. The approval
                 // then has no window it can ever be answered in.
                 cb(opts.noWindow ? undefined : { id: created.length });
@@ -2716,3 +2729,77 @@ describe("removing a site in Settings disconnects it", () => {
         expect(await siteAccounts(bg)).toEqual({ result: [signer.address] });
     });
 });
+
+// An approval window still open is often the last focused window, and headless
+// Chrome reports one as 1280x720. Centred on that, the next approval window
+// lands where the browser refuses to create it, and its request failed with no
+// window at all (https://git.eeqj.de/sneak/AutistMask/issues/290).
+describe("where an approval window opens", () => {
+    test("centred on the browser window the user was last in", async () => {
+        const bg = loadBackground({
+            lastFocused: {
+                type: "normal",
+                left: 0,
+                top: 0,
+                width: 1280,
+                height: 720,
+            },
+        });
+
+        bg.requestSign();
+        await settle();
+
+        expect(bg.created).toHaveLength(1);
+        expect(bg.created[0]).toMatchObject({ left: 460, top: 60 });
+    });
+
+    test("not centred on an approval window the user was last in", async () => {
+        const bg = loadBackground({
+            lastFocused: {
+                type: "popup",
+                left: 440,
+                top: 0,
+                width: 1280,
+                height: 720,
+            },
+        });
+
+        bg.requestSign();
+        await settle();
+
+        // Centred, it would be at left 900, the position the browser refused.
+        expect(bg.created).toHaveLength(1);
+        expect(bg.created[0].left).toBeUndefined();
+        expect(bg.created[0].top).toBeUndefined();
+    });
+
+    test("placed by the browser when it refuses the centred position", async () => {
+        const bg = loadBackground({
+            refusePosition: true,
+            lastFocused: {
+                type: "normal",
+                left: 1500,
+                top: 900,
+                width: 400,
+                height: 300,
+            },
+        });
+
+        const sign = bg.requestSign();
+        await settle();
+
+        expect(bg.created).toHaveLength(2);
+        expect(bg.created[0]).toMatchObject({ left: 1520, top: 750 });
+        expect(bg.created[1].left).toBeUndefined();
+        expect(bg.created[1].top).toBeUndefined();
+
+        // The request waits on the second window rather than failing:
+        // closing that window is refusing the prompt.
+        expect(sign.result()).toBeNull();
+        bg.closeWindow(2);
+        await settle();
+        expect(sign.result()).toEqual({
+            error: { code: 4001, message: "User rejected the request." },
+        });
+    });
+});