Preserve query filters across reload and history traversal

src/Exceptionless.Web/ClientApp/e2e/tests/project-scoping.e2e.ts

@@ -50,5 +50,58 @@ test('operator can scope Events to a project and clear the project filter', asyn
 
         await expect(page).not.toHaveURL(/[?&]project=/);
         await expect(getVisibleText(page, e2eSecondaryProject.message)).toBeVisible({ timeout: 30_000 });
+
+        await page.goBack();
+        await expect(page).toHaveURL(new RegExp(`[?&]project=${e2eScenario.projectId}(?:&|$)`));
+        await expect(page.getByRole('button', { name: new RegExp(`^Project\\s+${escapeRegExp(e2eScenario.projectName)}`) })).toBeVisible();
+        await expect(getVisibleText(page, e2eSecondaryProject.message)).toBeHidden({ timeout: 30_000 });
+
+        await page.goForward();
+        await expect(page).not.toHaveURL(/[?&]project=/);
+        await expect(getVisibleText(page, e2eSecondaryProject.message)).toBeVisible({ timeout: 30_000 });
+    });
+});
+
+test('project scope on Most Frequent Errors survives immediate reload and history traversal', async ({ e2eApi, e2eScenario, page }) => {
+    await test.step('seed an error and scope the stack list from its details', async () => {
+        await seedRepresentativeEvent(e2eApi, e2eScenario.userToken, {
+            message: e2eScenario.message,
+            projectId: e2eScenario.projectId,
+            projectToken: e2eScenario.projectToken,
+            referenceId: e2eScenario.referenceId
+        });
+
+        await page.goto('/next/stack/most-frequent-errors');
+        const stackRow = getVisibleRow(page, e2eScenario.message);
+        await expect(stackRow).toBeVisible({ timeout: 30_000 });
+        await stackRow.click();
+
+        const stackSheet = page.getByRole('dialog', { name: 'Stack' });
+        await expect(stackSheet).toBeVisible();
+        await stackSheet.getByTitle(`Filter project:${e2eScenario.projectId}`).click();
+    });
+
+    await test.step('retain scope through an immediate reload', async () => {
+        await page.reload();
+
+        await expect(page).toHaveURL(new RegExp(`[?&]project=${e2eScenario.projectId}(?:&|$)`));
+        await expect(page.getByRole('button', { name: new RegExp(`^Project\\s+${escapeRegExp(e2eScenario.projectName)}`) })).toBeVisible();
+        await expect(page.getByTitle('Refresh results').locator('svg')).not.toHaveClass(/animate-spin/);
+    });
+
+    await test.step('restore the scoped and unscoped states through Back and Forward', async () => {
+        const projectFilter = page.getByRole('button', { name: new RegExp(`^Project\\s+${escapeRegExp(e2eScenario.projectName)}`) });
+        await projectFilter.click();
+        await expect(projectFilter).toHaveAttribute('aria-expanded', 'true');
+        await page.getByRole('button', { name: 'Remove filter' }).click();
+        await expect(page).not.toHaveURL(/[?&]project=/);
+
+        await page.goBack();
+        await expect(page).toHaveURL(new RegExp(`[?&]project=${e2eScenario.projectId}(?:&|$)`));
+        await expect(projectFilter).toBeVisible();
+
+        await page.goForward();
+        await expect(page).not.toHaveURL(/[?&]project=/);
+        await expect(projectFilter).toBeHidden();
     });
 });

src/Exceptionless.Web/ClientApp/src/lib/features/shared/query-params/README.md

@@ -5,10 +5,11 @@ Exceptionless's shared Svelte query-parameter state module. It is intentionally
 - top-level string, number, boolean, date, and enum parameters;
 - typed property access and atomic multi-parameter updates;
 - preservation of unrelated URL parameters;
-- debounced push or replace navigation;
+- immediate, reload-safe URL synchronization;
+- coalescing of rapid push-history updates into one Back-button entry;
 - synchronization with browser navigation;
 - no state, URL, or history writes for unchanged values after coercion;
-- cancellation of pending synchronization during navigation and component teardown.
+- settlement of history-entry coalescing during navigation and component teardown.
 
 ```ts
 import { createQueryParameters } from '$shared/query-params';
@@ -27,4 +28,6 @@ queryParams.update({ filter: 'status:open', page: 1 });
 
 Updates may also assign a single schema property directly. Use `update()` when several parameters form one logical state change so they produce one reactive update and one URL synchronization.
 
+With `history: 'push'`, the first update immediately pushes a durable Back-button entry. Rapid follow-up updates are coalesced into one replacement after `debounceMilliseconds`, avoiding browser History API mutation limits, and a pending replacement is flushed before reload, link navigation, or teardown. If a burst returns to its starting URL, comparison is independent of query encoding and parameter order, and the return is pushed so the transient state remains a meaningful Back target rather than creating adjacent duplicate URLs. Immediate Back keeps a pending replacement associated with its unique source entry; Forward restores the latest value after route teardown or reload without rewriting the Back destination or replaying it onto a later visit to the same URL. Session-storage persistence is best-effort; if browser policy denies storage, current-page coalescing continues without blocking hydration. With `history: 'replace'`, every update immediately replaces the current entry.
+
 The implementation was originally derived from [beynar/kit-query-params](https://github.com/beynar/kit-query-params) version 0.0.26 at commit `7c90edf7`. The original copyright and MIT license are retained in [LICENSE](./LICENSE). This module is maintained as first-party Exceptionless code and does not track the upstream package API.