test: guard engines.vscode against Cursor's VS Code base

test/suite/vscodeEngine.test.ts

@@ -0,0 +1,48 @@
+import * as fs from "fs";
+import * as path from "path";
+import * as QUnit from "qunit";
+
+// The VS Code version that the current Cursor release ships as its base. Cursor
+// tracks several minor versions behind upstream VS Code, so an `engines.vscode`
+// requirement newer than this makes the extension fail to install on Cursor
+// (it shows up greyed out / non-functional until manually downgraded).
+//
+// Bump this only after confirming the Cursor base has actually moved forward.
+// See https://github.com/slackhq/vscode-hack/pull/281 for the change that
+// motivated this guard.
+const CURSOR_VSCODE_BASE = { major: 1, minor: 105 };
+
+// Parses a caret range like "^1.105.0" into its minimum { major, minor }.
+function parseMinimumVersion(range: string): { major: number; minor: number } {
+  const match = /^\^?(\d+)\.(\d+)\./.exec(range);
+  if (!match) {
+    throw new Error(`Unable to parse VS Code engine range: ${range}`);
+  }
+  return { major: Number(match[1]), minor: Number(match[2]) };
+}
+
+QUnit.module("vscode engine compatibility", () => {
+  const pkg = JSON.parse(
+    fs.readFileSync(path.resolve(__dirname, "../../../package.json"), "utf8"),
+  ) as { engines: { vscode: string } };
+
+  QUnit.test(
+    "engines.vscode stays compatible with the Cursor VS Code base",
+    (assert) => {
+      const min = parseMinimumVersion(pkg.engines.vscode);
+
+      const withinRange =
+        min.major < CURSOR_VSCODE_BASE.major ||
+        (min.major === CURSOR_VSCODE_BASE.major &&
+          min.minor <= CURSOR_VSCODE_BASE.minor);
+
+      assert.true(
+        withinRange,
+        `engines.vscode (${pkg.engines.vscode}) requires a newer VS Code than ` +
+          `Cursor's base (${CURSOR_VSCODE_BASE.major}.${CURSOR_VSCODE_BASE.minor}.x); ` +
+          `the extension will fail to install on Cursor. Relax the requirement or ` +
+          `update CURSOR_VSCODE_BASE once Cursor's base has moved forward.`,
+      );
+    },
+  );
+});