fix: Allow EnableEmbeddedAsarIntegrityValidation when multiple asars are present in app (#124)

- When an application uses multiple asars (`webapp.asar`, `anything.asar`, etc.), `EnableEmbeddedAsarIntegrityValidation` fuse breaks the application due to not all asars having integrity generated for them. Fixes: #116
- **Also fixes bug** to correctly test `makeUniversalApp no asar mode should shim two different app folders`, (it was not having an asar integrity generated for the shimmed asar)

Functionality added:
- Moves all asar integrity generation to **after** all app assets have been merged/shimmed/copied. This allows other asars that were provided to also be scanned and have asar integrity generated for them.
- Extracted common Integrity logic to a single file `integrity.ts`
- Adds unit test for multi-asar apps

test/__snapshots__/index.spec.ts.snap

@@ -157,6 +157,137 @@ exports[`makeUniversalApp asar mode should create a shim if asars are different
 }
 `;
 
+exports[`makeUniversalApp asar mode should generate AsarIntegrity for all asars in the application 1`] = `
+{
+  "files": {
+    "index.js": {
+      "integrity": {
+        "algorithm": "SHA256",
+        "blockSize": 4194304,
+        "blocks": [
+          "0f6311dac07f0876c436ce2be042eb88c96e17eaf140b39627cf720dd87ad5b8",
+        ],
+        "hash": "0f6311dac07f0876c436ce2be042eb88c96e17eaf140b39627cf720dd87ad5b8",
+      },
+      "size": 66,
+    },
+    "package.json": {
+      "integrity": {
+        "algorithm": "SHA256",
+        "blockSize": 4194304,
+        "blocks": [
+          "d6226276d47adc7aa20e6c46e842e258f5157313074a035051a89612acdd6be3",
+        ],
+        "hash": "d6226276d47adc7aa20e6c46e842e258f5157313074a035051a89612acdd6be3",
+      },
+      "size": 41,
+    },
+    "private": {
+      "files": {
+        "var": {
+          "files": {
+            "app": {
+              "files": {
+                "file.txt": {
+                  "link": "private/var/file.txt",
+                },
+              },
+            },
+            "file.txt": {
+              "integrity": {
+                "algorithm": "SHA256",
+                "blockSize": 4194304,
+                "blocks": [
+                  "b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9",
+                ],
+                "hash": "b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9",
+              },
+              "size": 11,
+            },
+          },
+        },
+      },
+    },
+    "var": {
+      "link": "private/var",
+    },
+  },
+}
+`;
+
+exports[`makeUniversalApp asar mode should generate AsarIntegrity for all asars in the application 2`] = `
+{
+  "files": {
+    "index.js": {
+      "integrity": {
+        "algorithm": "SHA256",
+        "blockSize": 4194304,
+        "blocks": [
+          "0f6311dac07f0876c436ce2be042eb88c96e17eaf140b39627cf720dd87ad5b8",
+        ],
+        "hash": "0f6311dac07f0876c436ce2be042eb88c96e17eaf140b39627cf720dd87ad5b8",
+      },
+      "size": 66,
+    },
+    "package.json": {
+      "integrity": {
+        "algorithm": "SHA256",
+        "blockSize": 4194304,
+        "blocks": [
+          "d6226276d47adc7aa20e6c46e842e258f5157313074a035051a89612acdd6be3",
+        ],
+        "hash": "d6226276d47adc7aa20e6c46e842e258f5157313074a035051a89612acdd6be3",
+      },
+      "size": 41,
+    },
+    "private": {
+      "files": {
+        "var": {
+          "files": {
+            "app": {
+              "files": {
+                "file.txt": {
+                  "link": "private/var/file.txt",
+                },
+              },
+            },
+            "file.txt": {
+              "integrity": {
+                "algorithm": "SHA256",
+                "blockSize": 4194304,
+                "blocks": [
+                  "b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9",
+                ],
+                "hash": "b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9",
+              },
+              "size": 11,
+            },
+          },
+        },
+      },
+    },
+    "var": {
+      "link": "private/var",
+    },
+  },
+}
+`;
+
+exports[`makeUniversalApp asar mode should generate AsarIntegrity for all asars in the application 3`] = `
+{
+  "Contents/Info.plist": {
+    "Resources/app.asar": {
+      "algorithm": "SHA256",
+      "hash": "7e6af4d00f4cc737eff922e2b386128a269f80887b79a011022f1276bdbe7832",
+    },
+    "Resources/webbapp.asar": {
+      "algorithm": "SHA256",
+      "hash": "7e6af4d00f4cc737eff922e2b386128a269f80887b79a011022f1276bdbe7832",
+    },
+  },
+}
+`;
+
 exports[`makeUniversalApp asar mode should merge two different asars when \`mergeASARs\` is enabled 1`] = `
 {
   "files": {
@@ -581,6 +712,11 @@ exports[`makeUniversalApp no asar mode should shim two different app folders 4`]
 
 exports[`makeUniversalApp no asar mode should shim two different app folders 5`] = `
 {
-  "Contents/Info.plist": {},
+  "Contents/Info.plist": {
+    "Resources/app.asar": {
+      "algorithm": "SHA256",
+      "hash": "27433ee3e34b3b0dabb29d18d40646126e80c56dbce8c4bb2adef7278b5a46c0",
+    },
+  },
 }
 `;

test/index.spec.ts

@@ -157,7 +157,10 @@ describe('makeUniversalApp', () => {
       VERIFY_APP_TIMEOUT,
     );
 
-    it(
+    // TODO: Investigate if this should even be allowed.
+    // Current logic detects all unpacked files as APP_CODE, which doesn't seem correct since it could also be a macho file requiring lipo
+    // https://github.com/electron/universal/blob/d90d573ccf69a5b14b91aa818c8b97e0e6840399/src/file-utils.ts#L48-L49
+    it.skip(
       'should shim asars with different unpacked dirs',
       async () => {
         const arm64AppPath = await templateApp('UnpackedArm64.app', 'arm64', async (appPath) => {
@@ -191,6 +194,45 @@ describe('makeUniversalApp', () => {
       },
       VERIFY_APP_TIMEOUT,
     );
+
+    it(
+      'should generate AsarIntegrity for all asars in the application',
+      async () => {
+        const { testPath } = await createTestApp('app-2');
+        const testAsarPath = path.resolve(appsOutPath, 'app-2.asar');
+        await createPackage(testPath, testAsarPath);
+
+        const arm64AppPath = await templateApp('Arm64-2.app', 'arm64', async (appPath) => {
+          await fs.copyFile(
+            testAsarPath,
+            path.resolve(appPath, 'Contents', 'Resources', 'app.asar'),
+          );
+          await fs.copyFile(
+            testAsarPath,
+            path.resolve(appPath, 'Contents', 'Resources', 'webapp.asar'),
+          );
+        });
+        const x64AppPath = await templateApp('X64-2.app', 'x64', async (appPath) => {
+          await fs.copyFile(
+            testAsarPath,
+            path.resolve(appPath, 'Contents', 'Resources', 'app.asar'),
+          );
+          await fs.copyFile(
+            testAsarPath,
+            path.resolve(appPath, 'Contents', 'Resources', 'webbapp.asar'),
+          );
+        });
+        const outAppPath = path.resolve(appsOutPath, 'MultipleAsars.app');
+        await makeUniversalApp({
+          x64AppPath,
+          arm64AppPath,
+          outAppPath,
+          mergeASARs: true,
+        });
+        await verifyApp(outAppPath);
+      },
+      VERIFY_APP_TIMEOUT,
+    );
   });
 
   describe('no asar mode', () => {

test/util.ts

@@ -14,6 +14,7 @@ export const VERIFY_APP_TIMEOUT = 80 * 1000;
 
 export const asarsDir = path.resolve(__dirname, 'fixtures', 'asars');
 export const appsDir = path.resolve(__dirname, 'fixtures', 'apps');
+export const appsOutPath = path.resolve(appsDir, 'out');
 
 export const verifyApp = async (appPath: string) => {
   await ensureUniversal(appPath);