test(spinner): add transform test back (#31017)

Issue number: N/A

---------

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issue. -->

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## What is the current behavior?
<!-- Please describe the current behavior that you are modifying. -->

While working on the migration for the spinner to Ionic Modular, I
noticed that we had a [Transform test
page](https://github.com/ionic-team/ionic-framework/blob/2b5b9137fc164c2f3305e493510a884c0afbfcf0/core/src/components/spinner/test/transform/index.html#L5)
without any context of why it was there. I found out that it's meant for
a [bug](#19247) that
was reported in v4 and we did have a
[test](https://github.com/ionic-team/ionic-framework/pull/24643/changes#diff-7b7ff84d3845fbde015775aa2da960310e80f79ec01b1f4a5957d751eddce7c9R1)
for it at some point but it was removed at a later date because it was
[discovered](#25259)
that it wasn't doing anything.

So we don't have any coverage of it if there's a regression.

## What is the new behavior?
<!-- Please describe the behavior or changes that are being added by
this PR. -->

- Added a test to prevent a regression

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

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## Other information

<!-- Any other information that is important to this PR such as
screenshots of how the component looks before and after the change. -->

How to test:
1. Be on your local
2. Navigate to `spinner.scss`
3. Update the following code snippet:
```diff
- :host(.spinner-circular) svg {
+ :host(.spinner-circular) {
  animation: spinner-circular linear infinite;
}
```
4. By making this code change, we are introducing the [original
issue](https://github.com/ionic-team/ionic-framework/pull/24643/changes#diff-fa8f6fb72eceb39e2482c0dbc083f69ecdabd411be541c21947f8e8e9bf9ee48L118).
5. Run the test
6. Notice that it fails
7. Undo the code change
8. Run the test
9. Verify that it passes

Author: thetaPC

core/src/components/spinner/test/transform/spinner.e2e.ts

@@ -0,0 +1,47 @@
+import { expect } from '@playwright/test';
+import { configs, test } from '@utils/test/playwright';
+
+/**
+ * This behavior does not vary across directions/modes.
+ */
+configs({ directions: ['ltr'], modes: ['md'] }).forEach(({ title, config }) => {
+  test.describe(title('spinner: transform'), () => {
+    test('should not overwrite circular animation when transform style is applied', async ({ page }, testInfo) => {
+      testInfo.annotations.push({
+        type: 'issue',
+        description: 'https://github.com/ionic-team/ionic-framework/issues/19247',
+      });
+
+      await page.setContent(
+        `
+          <style>
+            ion-spinner {
+              position: absolute;
+              left: 50%;
+              top: 50%;
+              transform: translate(-50%, -50%);
+            }
+          </style>
+    
+          <ion-spinner name="circular"></ion-spinner>
+        `,
+        config
+      );
+
+      const spinner = page.locator('ion-spinner');
+
+      // Get initial position
+      const initialBox = await spinner.boundingBox();
+
+      // Wait for a few animation cycles
+      await page.waitForTimeout(500);
+
+      // Get position after the cycles
+      const finalBox = await spinner.boundingBox();
+
+      // The x and y coordinates should remain identical
+      expect(initialBox!.x).toBe(finalBox!.x);
+      expect(initialBox!.y).toBe(finalBox!.y);
+    });
+  });
+});