fix!: Automatically move host_permissions to permissions for MV2 (#626)

BREAKING CHANGE: Out of an abundance of caution, I've marked this as a breaking change because permission generation has changed. ***If you list `host_permissions` in your `wxt.config.ts`'s manifest and have released your extension***, double check that your `permissions` and `host_permissions` have not changed for all browsers you target. Permission changes can cause the extension to be disabled on update, and can cause a drop in users, so be sure to double check for differences compared to the previous manifest version.

src/core/utils/__tests__/manifest.test.ts

@@ -1447,6 +1447,53 @@ describe('Manifest Utils', () => {
         },
       );
     });
+
+    describe('host_permissions', () => {
+      it('should keep host_permissions as-is for MV3', async () => {
+        const expectedHostPermissions = ['https://google.com/*'];
+        const expectedPermissions = ['scripting'];
+        setFakeWxt({
+          config: {
+            manifest: {
+              host_permissions: expectedHostPermissions,
+              permissions: expectedPermissions,
+            },
+            manifestVersion: 3,
+            command: 'build',
+          },
+        });
+        const output = fakeBuildOutput();
+
+        const { manifest: actual } = await generateManifest([], output);
+
+        expect(actual.permissions).toEqual(expectedPermissions);
+        expect(actual.host_permissions).toEqual(expectedHostPermissions);
+      });
+
+      it('should move host_permissions to permissions for MV2, ignoring duplicates', async () => {
+        const expectedPermissions = [
+          'scripting',
+          '*://*.youtube.com/*',
+          'https://google.com/*',
+        ];
+        setFakeWxt({
+          config: {
+            manifest: {
+              host_permissions: ['https://google.com/*', '*://*.youtube.com/*'],
+              permissions: ['scripting', '*://*.youtube.com/*'],
+            },
+            manifestVersion: 2,
+            command: 'build',
+          },
+        });
+        const output = fakeBuildOutput();
+
+        const { manifest: actual } = await generateManifest([], output);
+
+        expect(actual.permissions).toEqual(expectedPermissions);
+        expect(actual.host_permissions).toBeUndefined();
+      });
+    });
   });
 
   describe('stripPathFromMatchPattern', () => {

src/core/utils/manifest.ts

@@ -117,6 +117,7 @@ export async function generateManifest(
   if (wxt.config.manifestVersion === 2) {
     convertWebAccessibleResourcesToMv2(manifest);
     convertActionToMv2(manifest);
+    moveHostPermissionsToPermissions(manifest);
   }
 
   if (wxt.config.manifestVersion === 3) {
@@ -617,6 +618,17 @@ export function convertWebAccessibleResourcesToMv2(
   );
 }
 
+function moveHostPermissionsToPermissions(
+  manifest: Manifest.WebExtensionManifest,
+): void {
+  if (!manifest.host_permissions?.length) return;
+
+  manifest.host_permissions.forEach((permission) =>
+    addPermission(manifest, permission),
+  );
+  delete manifest.host_permissions;
+}
+
 function convertActionToMv2(manifest: Manifest.WebExtensionManifest): void {
   if (
     manifest.action == null ||