fix(extension): icon exceeds the Marketplace size limit

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Fixed
+
+- The VS Code extension icon fits within the Marketplace's 1024 × 1024 pixel limit, which blocked publishing 0.1.5 to the Marketplace.
+
 ## 0.1.5
 
 ### Fixed

test/vsix.spec.test.ts

@@ -4,14 +4,17 @@
 
 import { readFile } from "node:fs/promises";
 import { unzipSync } from "fflate";
-import { expect, it } from "vitest";
+import { assert, expect, it } from "vitest";
 import { z } from "zod";
 import {
   extensionArchivePath,
   packageManifest,
 } from "../scripts/package/metadata.js";
 import { extensionFileList } from "./package/contents.js";
 
+// The Marketplace rejects a larger icon at publication.
+const MAXIMUM_ICON_DIMENSION = 1_024;
+
 it("contains only the extension runtime and required metadata", async () => {
   expect(
     Object.keys(
@@ -72,3 +75,21 @@ it("targets the Busy Octopus UI extension", async () => {
     new Uint8Array(await readFile(manifest.icon)),
   );
 });
+
+it("keeps the icon within the Marketplace dimension limit", async () => {
+  const icon = unzipSync(new Uint8Array(await readFile(extensionArchivePath)))[
+    `extension/${packageManifest.icon}`
+  ];
+
+  assert(icon !== undefined);
+  // A PNG signature is followed by the IHDR chunk, whose data starts with the width and height.
+  expect(Array.from(icon.subarray(0, 8))).toEqual([
+    0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a,
+  ]);
+  expect(new TextDecoder().decode(icon.subarray(12, 16))).toBe("IHDR");
+
+  const view = new DataView(icon.buffer, icon.byteOffset, icon.byteLength);
+
+  expect(view.getUint32(16)).toBeLessThanOrEqual(MAXIMUM_ICON_DIMENSION);
+  expect(view.getUint32(20)).toBeLessThanOrEqual(MAXIMUM_ICON_DIMENSION);
+});