Allow computeBaseline() with no keys, formally (#3960)

Author: ddbeck

packages/compute-baseline/src/baseline/index.test.ts

@@ -175,6 +175,15 @@ describe("computeBaseline", function () {
     });
     assert.equal(actual.baseline, false);
   });
+
+  it("returns no support for no keys", function () {
+    const actual = computeBaseline({
+      compatKeys: [],
+      checkAncestors: false,
+    });
+    assert.equal(actual.baseline, false);
+    assert.equal(actual.support.size, 0);
+  });
 });
 
 describe("keystoneDateToStatus()", function () {

packages/compute-baseline/src/baseline/index.ts

@@ -94,7 +94,7 @@ export function getStatus(
  */
 export function computeBaseline(
   featureSelector: {
-    compatKeys: [string, ...string[]];
+    compatKeys: string[];
     checkAncestors?: boolean;
   },
   compat: Compat = defaultCompat,