feat(formats): add arazzo format (stoplightio#2663)

Author: frankkilcommins

packages/formats/src/__tests__/arazzo.test.ts

@@ -0,0 +1,27 @@
+import { arazzo1_0 } from '../arazzo';
+
+describe('Arazzo format', () => {
+  describe('Arazzo 1.0.x', () => {
+    it.each(['1.0.0', '1.0', '1.0.1', '1.0.2', '1.0.99'])('recognizes %s version correctly', version => {
+      expect(arazzo1_0({ arazzo: version }, null)).toBe(true);
+    });
+
+    const testCases = [
+      { arazzo: '0.1' },
+      { arazzo: '1.1.0' },
+      { arazzo: '2' },
+      { arazzo: '2.0' },
+      { arazzo: '2.0.' },
+      { arazzo: '2.0.01' },
+      { arazzo: 2 },
+      { arazzo: null },
+      { arazzo: '4.0' },
+      {},
+      null,
+    ];
+
+    it.each(testCases)('does not recognize invalid document %o', document => {
+      expect(arazzo1_0(document, null)).toBe(false);
+    });
+  });
+});

packages/formats/src/arazzo.ts

@@ -0,0 +1,12 @@
+import type { Format } from '@stoplight/spectral-core';
+import { isPlainObject } from '@stoplight/json';
+
+type MaybeArazzo = { arazzo: unknown } & Record<string, unknown>;
+
+const arazzo1_0Regex = /^1\.0(?:\.[0-9]*)?$/;
+
+const isArazzo = (document: unknown): document is { arazzo: string } & Record<string, unknown> =>
+  isPlainObject(document) && 'arazzo' in document && arazzo1_0Regex.test(String((document as MaybeArazzo).arazzo));
+
+export const arazzo1_0: Format = isArazzo;
+arazzo1_0.displayName = 'Arazzo 1.0.x';

packages/formats/src/index.ts

@@ -1,3 +1,4 @@
 export * from './openapi';
 export * from './asyncapi';
 export * from './jsonSchema';
+export * from './arazzo';