fix: Move isMacOs to browser.ts to fix SSR error

The isMacOs() function used the `browser` variable from SvelteKit's
$app/environment but the import was missing after a rebase, causing
a ReferenceError during SSR that broke all e2e tests.

Moved isMacOs() from generic.ts to browser.ts for better separation
of concerns and updated all import references.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: AaronPlave

src/components/parameters/ExtraneousParameters.svelte

@@ -6,7 +6,7 @@
   import { createEventDispatcher } from 'svelte';
   import type { ActivityErrorCategories } from '../../types/errors';
   import type { ArgumentsMap } from '../../types/parameter';
-  import { isMacOs } from '../../utilities/generic';
+  import { isMacOs } from '../../utilities/browser';
   import { isMetaOrCtrlPressed } from '../../utilities/keyboardEvents';
   import { permissionHandler } from '../../utilities/permissionHandler';
   import { pluralize } from '../../utilities/text';

src/components/parameters/ValueSourceBadge.svelte

@@ -4,7 +4,8 @@
   import { browser } from '$app/environment';
   import { createEventDispatcher } from 'svelte';
   import type { ParameterType, ValueSource } from '../../types/parameter';
-  import { classNames, isMacOs } from '../../utilities/generic';
+  import { isMacOs } from '../../utilities/browser';
+  import { classNames } from '../../utilities/generic';
   import { isMetaOrCtrlPressed } from '../../utilities/keyboardEvents';
   import { tooltip } from '../../utilities/tooltip';
   import { useActions, type ActionArray } from '../../utilities/useActions';

src/components/sequencing/EditorToolbar.svelte

@@ -5,7 +5,7 @@
   import { Braces, Bug, Clipboard, Download, FileOutput } from 'lucide-svelte';
   import { createEventDispatcher } from 'svelte';
   import type { ActionDefinition } from '../../types/actions';
-  import { isMacOs } from '../../utilities/generic';
+  import { isMacOs } from '../../utilities/browser';
   import Tooltip from '../ui/Tooltip.svelte';
   import SequenceActionCombobox from './SequenceActionCombobox.svelte';
 

src/components/timeline/TimelineInteractionModeControl.svelte

@@ -2,8 +2,7 @@
   import CursorDefaultIcon from '@nasa-jpl/stellar/icons/cursor_default.svg?component';
   import MoveIcon from '@nasa-jpl/stellar/icons/move.svg?component';
   import { createEventDispatcher, onMount } from 'svelte';
-  import { addPageFocusListener } from '../../utilities/browser';
-  import { isMacOs } from '../../utilities/generic';
+  import { addPageFocusListener, isMacOs } from '../../utilities/browser';
   import { isMetaOrCtrlPressed } from '../../utilities/keyboardEvents';
   import { TimelineInteractionMode } from '../../utilities/timeline';
   import { tooltip } from '../../utilities/tooltip';

src/components/ui/ActivityErrorsRollup.svelte

@@ -15,7 +15,7 @@
   import OutsideBoundsIcon from '../../assets/out-of-bounds.svg?component';
   import type { Dispatcher } from '../../types/component';
   import type { ActivityErrorCategories, ActivityErrorCounts } from '../../types/errors';
-  import { isMacOs } from '../../utilities/generic';
+  import { isMacOs } from '../../utilities/browser';
   import { isMetaOrCtrlPressed } from '../../utilities/keyboardEvents';
   import { permissionHandler } from '../../utilities/permissionHandler';
   import { pluralize } from '../../utilities/text';

src/utilities/browser.test.ts

@@ -0,0 +1,47 @@
+import { afterAll, describe, expect, test, vi } from 'vitest';
+
+vi.mock('$app/environment', () => ({
+  browser: true,
+}));
+
+import { isMacOs } from './browser';
+
+const mockNavigator = {
+  platform: 'MacIntel',
+};
+
+vi.stubGlobal('navigator', mockNavigator);
+
+describe('Browser utility function tests', () => {
+  afterAll(() => {
+    vi.restoreAllMocks();
+  });
+
+  describe('isMacOs', () => {
+    test('Should return true for Mac browsers', () => {
+      expect(isMacOs()).toEqual(true);
+
+      mockNavigator.platform = 'MacPPC';
+      expect(isMacOs()).toEqual(true);
+
+      mockNavigator.platform = 'Mac68K';
+      expect(isMacOs()).toEqual(true);
+    });
+
+    test('Should return false for Windows browsers', () => {
+      mockNavigator.platform = 'Win32';
+      expect(isMacOs()).toEqual(false);
+
+      mockNavigator.platform = 'Windows';
+      expect(isMacOs()).toEqual(false);
+    });
+
+    test('Should return false for Linux browsers', () => {
+      mockNavigator.platform = 'Linux i686';
+      expect(isMacOs()).toEqual(false);
+
+      mockNavigator.platform = 'Linux x86_64';
+      expect(isMacOs()).toEqual(false);
+    });
+  });
+});

src/utilities/browser.ts

@@ -1,5 +1,18 @@
 import { browser } from '$app/environment';
 
+/**
+ * Returns true if the current browser is running on MacOS
+ */
+export function isMacOs(): boolean {
+  if (!browser) {
+    return false;
+  }
+  // userAgentData is not yet in TypeScript's Navigator type (only supported in Chromium browsers)
+  const nav = navigator as Navigator & { userAgentData?: { platform: string } };
+  const platform = nav.userAgentData?.platform ?? navigator.platform;
+  return /mac/i.test(platform);
+}
+
 /**
  * Adds event listeners to document and window to track if the page is in focus.
  * Returns a function that when called will remove the listeners.

src/utilities/generic.test.ts

@@ -11,18 +11,11 @@ import {
   extractQuotes,
   filterEmpty,
   filterNullish,
-  isMacOs,
   lowercase,
   parseJSONStream,
   unique,
 } from './generic';
 
-const mockNavigator = {
-  platform: 'MacIntel',
-};
-
-vi.stubGlobal('navigator', mockNavigator);
-
 describe('Generic utility function tests', () => {
   afterAll(() => {
     vi.restoreAllMocks();
@@ -129,34 +122,6 @@ describe('Generic utility function tests', () => {
     });
   });
 
-  describe('isMacOs', () => {
-    test('Should return true for Mac browsers', () => {
-      expect(isMacOs()).toEqual(true);
-
-      mockNavigator.platform = 'MacPPC';
-      expect(isMacOs()).toEqual(true);
-
-      mockNavigator.platform = 'Mac68K';
-      expect(isMacOs()).toEqual(true);
-    });
-
-    test('Should return false for Windows browsers', () => {
-      mockNavigator.platform = 'Win32';
-      expect(isMacOs()).toEqual(false);
-
-      mockNavigator.platform = 'Windows';
-      expect(isMacOs()).toEqual(false);
-    });
-
-    test('Should return false for Linux browsers', () => {
-      mockNavigator.platform = 'Linux i686';
-      expect(isMacOs()).toEqual(false);
-
-      mockNavigator.platform = 'Linux x86_64';
-      expect(isMacOs()).toEqual(false);
-    });
-  });
-
   describe('unique', () => {
     test('Should make a list of primitives unique', () => {
       const base = [1, 7, 1, 3, 2, 4, 3, 4, 15, 10, 10];

src/utilities/generic.ts

@@ -139,19 +139,6 @@ export function isEmpty(value: any): boolean {
   return value === null || value === undefined || value === '' || Number.isNaN(value);
 }
 
-/**
- * Returns true if the current browser is running on MacOS
- */
-export function isMacOs(): boolean {
-  if (!browser) {
-    return false;
-  }
-  // userAgentData is not yet in TypeScript's Navigator type (only supported in Chromium browsers)
-  const nav = navigator as Navigator & { userAgentData?: { platform: string } };
-  const platform = nav.userAgentData?.platform ?? navigator.platform;
-  return /mac/i.test(platform);
-}
-
 /**
  * Returns true if the mouse event is a right click
  */

src/utilities/keyboardEvents.ts

@@ -1,4 +1,4 @@
-import { isMacOs } from './generic';
+import { isMacOs } from './browser';
 
 export function isMetaOrCtrlPressed(event: KeyboardEvent | MouseEvent) {
   return isMacOs() ? event.metaKey : event.ctrlKey;