fix(fab): apply safe area in positioning to proper side regardless of direction

core/src/components/fab/fab.scss

@@ -23,15 +23,29 @@
 }
 
 :host(.fab-horizontal-start) {
-  @include position-horizontal(
-    calc(#{$fab-content-margin} + var(--ion-safe-area-left, 0px)), null
-  );
+  /* stylelint-disable */
+  @include ltr() {
+    left: calc(#{$fab-content-margin} + var(--ion-safe-area-left, 0px));
+  }
+
+  @include rtl() {
+    right: calc(#{$fab-content-margin} + var(--ion-safe-area-right, 0px));
+    left: unset;
+  }
+  /* stylelint-enable */
 }
 
 :host(.fab-horizontal-end) {
-  @include position-horizontal(
-    null, calc(#{$fab-content-margin} + var(--ion-safe-area-right, 0px))
-  );
+  /* stylelint-disable */
+  @include ltr() {
+    right: calc(#{$fab-content-margin} + var(--ion-safe-area-right, 0px));
+  }
+
+  @include rtl() {
+    left: calc(#{$fab-content-margin} + var(--ion-safe-area-left, 0px));
+    right: unset;
+  }
+  /* stylelint-enable */
 }
 
 

core/src/components/fab/test/safe-area/fab.e2e.ts

@@ -0,0 +1,72 @@
+import { expect } from '@playwright/test';
+import { configs, test } from '@utils/test/playwright';
+
+configs({ modes: ['md'] }).forEach(({ title, screenshot, config }) => {
+  test.describe(title('fab: safe area'), () => {
+    test('should ignore document direction in safe area positioning for start-positioned fab', async ({ page }) => {
+      await page.setContent(
+        `
+          <style>
+            :root {
+              --ion-safe-area-left: 40px;
+              --ion-safe-area-right: 20px;
+            }
+          </style>
+
+          <ion-content>
+            <ion-fab vertical="center" horizontal="start">
+              <ion-fab-button>
+                <ion-icon name="add"></ion-icon>
+              </ion-fab-button>
+            </ion-fab>
+          </ion-content>
+        `,
+        config
+      );
+
+      /**
+       * We need to capture the entire page to check the fab's position,
+       * but we don't need much extra white space.
+       */
+      await page.setViewportSize({
+        width: 200,
+        height: 200,
+      });
+
+      await expect(page).toHaveScreenshot(screenshot('fab-safe-area-horizontal-start'));
+    });
+
+    test('should ignore document direction in safe area positioning for end-positioned fab', async ({ page }) => {
+      await page.setContent(
+        `
+          <style>
+            :root {
+              --ion-safe-area-left: 40px;
+              --ion-safe-area-right: 20px;
+            }
+          </style>
+
+          <ion-content>
+            <ion-fab vertical="center" horizontal="end">
+              <ion-fab-button>
+                <ion-icon name="add"></ion-icon>
+              </ion-fab-button>
+            </ion-fab>
+          </ion-content>
+        `,
+        config
+      );
+
+      /**
+       * We need to capture the entire page to check the fab's position,
+       * but we don't need much extra white space.
+       */
+      await page.setViewportSize({
+        width: 200,
+        height: 200,
+      });
+
+      await expect(page).toHaveScreenshot(screenshot('fab-safe-area-horizontal-end'));
+    });
+  });
+});