Fix unused permission detection for endowments with multiple handlers

Author: Mrtenz

packages/snaps-utils/src/manifest/validators/unused-exports.test.ts

@@ -91,4 +91,36 @@ describe('unusedExports', () => {
       ),
     );
   });
+
+  it('does not report if the Snap exports a handler and requests permission for it in the manifest', async () => {
+    const report = jest.fn();
+    assert(unusedExports.semanticCheck);
+
+    const files = getMockSnapFiles({
+      manifest: getSnapManifest({
+        initialPermissions: {
+          'endowment:page-home': {},
+          'endowment:rpc': {},
+          'endowment:lifecycle-hooks': {},
+        },
+      }),
+      manifestPath: __filename,
+    });
+
+    await unusedExports.semanticCheck(files, {
+      report,
+      options: {
+        exports: ['onRpcRequest', 'onHomePage', 'onInstall'],
+        handlerEndowments: {
+          onRpcRequest: 'endowment:rpc',
+          onHomePage: 'endowment:page-home',
+          onInstall: 'endowment:lifecycle-hooks',
+          onUpdate: 'endowment:lifecycle-hooks',
+          onUserInput: null,
+        },
+      },
+    });
+
+    expect(report).toHaveBeenCalledTimes(0);
+  });
 });

packages/snaps-utils/src/manifest/validators/unused-exports.ts

@@ -17,6 +17,16 @@ export const unusedExports: ValidatorMeta = {
       return;
     }
 
+    // Endowments used based on the exports from the Snap. This is used to
+    // filter endowments that are used by multiple handlers, e.g., the lifecycle
+    // handlers.
+    const usedEndowments = Object.entries(handlerEndowments)
+      .filter(
+        ([handler, endowment]) =>
+          endowment === null || exports.includes(handler),
+      )
+      .map(([, endowment]) => endowment);
+
     const unusedHandlers = Object.entries(handlerEndowments)
       .filter(([handler, endowment]) => {
         if (endowment === null) {
@@ -39,9 +49,11 @@ export const unusedExports: ValidatorMeta = {
         }
 
         return (
+          !usedEndowments.includes(endowment) &&
           files.manifest.result.initialPermissions[
             endowment as keyof InitialPermissions
-          ] && !exports.includes(handler)
+          ] &&
+          !exports.includes(handler)
         );
       },
     );