first commit

packages/cli/test/extend-expect.ts

@@ -0,0 +1,34 @@
+expect.extend({
+	toBeEmptyArray(this: jest.MatcherContext, actual: unknown) {
+		const pass = Array.isArray(actual) && actual.length === 0;
+
+		return {
+			pass,
+			message: pass
+				? () => `Expected ${actual} to be an empty array`
+				: () => `Expected ${actual} not to be an empty array`,
+		};
+	},
+
+	toBeEmptySet(this: jest.MatcherContext, actual: unknown) {
+		const pass = actual instanceof Set && actual.size === 0;
+
+		return {
+			pass,
+			message: pass
+				? () => `Expected ${[...actual]} to be an empty set`
+				: () => `Expected ${actual} not to be an empty set`,
+		};
+	},
+
+	toBeSetContaining(this: jest.MatcherContext, actual: unknown, ...expectedElements: string[]) {
+		const pass = actual instanceof Set && expectedElements.every((e) => actual.has(e));
+
+		return {
+			pass,
+			message: pass
+				? () => `Expected ${[...actual]} to be a set containing ${expectedElements}`
+				: () => `Expected ${actual} not to be a set containing ${expectedElements}`,
+		};
+	},
+});