Add screenshots field (#505)

This adds support for a screenshots field in the registry. Snaps may
have three screenshots, with a size of 960x540. Screenshots should be
placed in `src/images/<snapId>`, i.e.,
`src/images/@organisation/snap-name`, and should be named `1.png`,
`2.png`, `3.png` (or `.jpe?g`). They can then be added to the registry
by adding `screenshots` to the metadata, with the path to each file as
array items.

```json
{
  "verifiedSnaps": {
    "npm:@organisation/snap-name": {
      "metadata": {
        "screenshots": [
          "./images/@organisation/snap-name/1.png",
          "./images/@organisation/snap-name/2.png",
          "./images/@organisation/snap-name/3.png"
        ]
      }
    }
  }
}
```

package.json

@@ -59,6 +59,7 @@
     "eslint-plugin-prettier": "^4.2.1",
     "eslint-plugin-promise": "^6.1.1",
     "fast-deep-equal": "^3.1.3",
+    "image-size": "^1.1.1",
     "jest": "^28.1.3",
     "jest-it-up": "^2.0.2",
     "prettier": "^2.7.1",

scripts/verify-snaps.ts

@@ -1,14 +1,19 @@
 import { detectSnapLocation, fetchSnap } from '@metamask/snaps-controllers';
 import type { SnapId } from '@metamask/snaps-sdk';
 import { getLocalizedSnapManifest } from '@metamask/snaps-utils';
-import { assertIsSemVerVersion } from '@metamask/utils';
+import { assertIsSemVerVersion, getErrorMessage } from '@metamask/utils';
 import deepEqual from 'fast-deep-equal';
+import { imageSize as imageSizeSync } from 'image-size';
+import { resolve } from 'path';
 import semver from 'semver/preload';
 import type { Infer } from 'superstruct';
+import { promisify } from 'util';
 
 import type { VerifiedSnapStruct } from '../src';
 import registry from '../src/registry.json';
 
+const imageSize = promisify(imageSizeSync);
+
 type VerifiedSnap = Infer<typeof VerifiedSnapStruct>;
 
 /**
@@ -65,6 +70,51 @@ async function verifySnapVersion(
   }
 }
 
+/**
+ * Get the size of an image.
+ *
+ * @param path - The path to the image.
+ * @param snapId - The snap ID.
+ */
+async function getImageSize(path: string, snapId: string) {
+  try {
+    return await imageSize(path);
+  } catch (error) {
+    throw new Error(
+      `Could not determine the size of screenshot "${path}" for "${snapId}": ${getErrorMessage(
+        error,
+      )}.`,
+    );
+  }
+}
+
+/**
+ * Verify that the screenshots for a snap exist and have the correct dimensions.
+ *
+ * @param snapId - The snap ID.
+ * @param screenshots - The screenshots.
+ * @throws If a screenshot does not exist or has the wrong dimensions.
+ */
+async function verifyScreenshots(snapId: string, screenshots: string[]) {
+  const basePath = resolve(__dirname, '..', 'src');
+
+  for (const screenshot of screenshots) {
+    const path = resolve(basePath, screenshot);
+    const size = await getImageSize(path, snapId);
+    if (!size?.width || !size?.height) {
+      throw new Error(
+        `Could not determine the size of screenshot "${screenshot}" for "${snapId}".`,
+      );
+    }
+
+    if (size.width !== 960 || size.height !== 540) {
+      throw new Error(
+        `Screenshot "${screenshot}" for "${snapId}" does not have the correct dimensions. Expected 960x540, got ${size.width}x${size.height}.`,
+      );
+    }
+  }
+}
+
 /**
  * Verify a snap.
  *
@@ -91,6 +141,14 @@ async function verifySnap(snap: VerifiedSnap) {
       process.exitCode = 1;
     });
   }
+
+  const { screenshots } = snap.metadata;
+  if (screenshots) {
+    await verifyScreenshots(snap.id, screenshots).catch((error) => {
+      console.error(error.message);
+      process.exitCode = 1;
+    });
+  }
 }
 
 /**

src/index.ts

@@ -5,6 +5,8 @@ import {
 } from '@metamask/utils';
 import type { Infer } from 'superstruct';
 import {
+  pattern,
+  size,
   object,
   array,
   record,
@@ -53,6 +55,11 @@ export const AdditionalSourceCodeStruct = object({
   url: string(),
 });
 
+export const ImagePathStruct = pattern(
+  string(),
+  /\.\/images\/.*\/\d+\.(?:png|jpe?g)$/u,
+);
+
 export const VerifiedSnapStruct = object({
   id: NpmIdStruct,
   metadata: object({
@@ -80,6 +87,7 @@ export const VerifiedSnapStruct = object({
     privacyPolicy: optional(string()),
     termsOfUse: optional(string()),
     additionalSourceCode: optional(array(AdditionalSourceCodeStruct)),
+    screenshots: optional(size(array(ImagePathStruct), 3, 3)),
   }),
   versions: record(VersionStruct, VerifiedSnapVersionStruct),
 });

src/registry.test.ts

@@ -58,6 +58,11 @@ describe('Snaps Registry', () => {
                 url: 'https://metamask.io/example/source-code3',
               },
             ],
+            screenshots: [
+              './images/example-snap/1.png',
+              './images/example-snap/2.jpg',
+              './images/example-snap/3.jpeg',
+            ],
           },
           versions: {
             ['0.1.0' as SemVerVersion]: {
@@ -120,7 +125,7 @@ describe('Snaps Registry', () => {
     expect(() => assert(registryDb, SnapsRegistryDatabaseStruct)).not.toThrow();
   });
 
-  it('should throw when the metadata has an unexpected field', () => {
+  it('throws when the metadata has an unexpected field', () => {
     const registryDb: SnapsRegistryDatabase = {
       verifiedSnaps: {
         'npm:example-snap': {
@@ -145,4 +150,60 @@ describe('Snaps Registry', () => {
       'At path: verifiedSnaps.npm:example-snap.metadata.unexpected -- Expected a value of type `never`, but received: `"field"`',
     );
   });
+
+  it('throws when the screenshots are invalid', () => {
+    expect(() =>
+      assert(
+        {
+          verifiedSnaps: {
+            'npm:example-snap': {
+              id: 'npm:example-snap',
+              metadata: {
+                name: 'Example Snap',
+                screenshots: ['./images/example-snap/1.png'],
+              },
+              versions: {
+                ['0.1.0' as SemVerVersion]: {
+                  checksum: 'A83r5/ZIcKeKw3An13HBeV4CAofj7jGK5hOStmHY6A0=',
+                },
+              },
+            },
+          },
+          blockedSnaps: [],
+        },
+        SnapsRegistryDatabaseStruct,
+      ),
+    ).toThrow(
+      'At path: verifiedSnaps.npm:example-snap.metadata.screenshots -- Expected a array with a length of `3` but received one with a length of `1`',
+    );
+
+    expect(() =>
+      assert(
+        {
+          verifiedSnaps: {
+            'npm:example-snap': {
+              id: 'npm:example-snap',
+              metadata: {
+                name: 'Example Snap',
+                screenshots: [
+                  './images/example-snap/1.png',
+                  './images/example-snap/2.png',
+                  './images/example-snap/3.gif',
+                ],
+              },
+              versions: {
+                ['0.1.0' as SemVerVersion]: {
+                  checksum: 'A83r5/ZIcKeKw3An13HBeV4CAofj7jGK5hOStmHY6A0=',
+                },
+              },
+            },
+          },
+          blockedSnaps: [],
+        },
+        SnapsRegistryDatabaseStruct,
+      ),
+    ).toThrow(
+      'At path: verifiedSnaps.npm:example-snap.metadata.screenshots.2 -- Expected a string matching `/\\.\\/images\\/.*\\/\\d+\\.(?:png|jpe?g)$/` but received "./images/example-snap/3.gif"',
+    );
+  });
 });

yarn.lock

@@ -1236,6 +1236,7 @@ __metadata:
     eslint-plugin-prettier: ^4.2.1
     eslint-plugin-promise: ^6.1.1
     fast-deep-equal: ^3.1.3
+    image-size: ^1.1.1
     jest: ^28.1.3
     jest-it-up: ^2.0.2
     prettier: ^2.7.1
@@ -4065,6 +4066,17 @@ __metadata:
   languageName: node
   linkType: hard
 
+"image-size@npm:^1.1.1":
+  version: 1.1.1
+  resolution: "image-size@npm:1.1.1"
+  dependencies:
+    queue: 6.0.2
+  bin:
+    image-size: bin/image-size.js
+  checksum: 23b3a515dded89e7f967d52b885b430d6a5a903da954fce703130bfb6069d738d80e6588efd29acfaf5b6933424a56535aa7bf06867e4ebd0250c2ee51f19a4a
+  languageName: node
+  linkType: hard
+
 "immer@npm:^9.0.6":
   version: 9.0.21
   resolution: "immer@npm:9.0.21"
@@ -5913,6 +5925,15 @@ __metadata:
   languageName: node
   linkType: hard
 
+"queue@npm:6.0.2":
+  version: 6.0.2
+  resolution: "queue@npm:6.0.2"
+  dependencies:
+    inherits: ~2.0.3
+  checksum: ebc23639248e4fe40a789f713c20548e513e053b3dc4924b6cb0ad741e3f264dcff948225c8737834dd4f9ec286dbc06a1a7c13858ea382d9379f4303bcc0916
+  languageName: node
+  linkType: hard
+
 "react-is@npm:^18.0.0":
   version: 18.2.0
   resolution: "react-is@npm:18.2.0"