test: add unit tests for User-Agent header on HTTP(S) schema fetch

Cover version from env var, 'unknown' fallback, http:// parity,
Accept-Encoding preservation, successful response handling, and
xhr error rejection.

Author: svifred

test/schemaRequestHandler.test.ts

@@ -5,6 +5,8 @@
 
 import { schemaRequestHandler } from '../src/languageservice/services/schemaRequestHandler';
 import * as sinon from 'sinon';
+import * as request from 'request-light';
+import { XHRResponse } from 'request-light';
 import { Connection } from 'vscode-languageserver';
 import { URI } from 'vscode-uri';
 import * as chai from 'chai';
@@ -66,4 +68,85 @@ describe('Schema Request Handler Tests', () => {
       expect(result).to.be.equal('{some: "json"}');
     });
   });
+
+  describe('HTTP(S) schema requests', () => {
+    const sandbox = sinon.createSandbox();
+    let xhrStub: sinon.SinonStub;
+    const connection = {} as Connection;
+
+    beforeEach(() => {
+      xhrStub = sandbox.stub(request, 'xhr');
+      xhrStub.resolves({ responseText: '{"$schema":"http://json-schema.org/draft-07/schema"}', status: 200 } as XHRResponse);
+    });
+
+    afterEach(() => {
+      sandbox.restore();
+      delete process.env.YAML_LANGUAGE_SERVER_VERSION;
+    });
+
+    it('should send correct User-Agent with version, Node runtime and platform', async () => {
+      process.env.YAML_LANGUAGE_SERVER_VERSION = '1.0.0-test';
+      await schemaRequestHandler(connection, 'https://example.com/schema.json', [], URI.parse(''), false, testFileSystem, false);
+
+      expect(xhrStub).calledOnce;
+      const { headers } = xhrStub.firstCall.args[0];
+      expect(headers['User-Agent']).to.equal(
+        `yaml-language-server/1.0.0-test (RedHat) node/${process.versions.node} (${process.platform})`
+      );
+    });
+
+    it('should fall back to "unknown" version when YAML_LANGUAGE_SERVER_VERSION is not set', async () => {
+      delete process.env.YAML_LANGUAGE_SERVER_VERSION;
+      await schemaRequestHandler(connection, 'https://example.com/schema.json', [], URI.parse(''), false, testFileSystem, false);
+
+      const { headers } = xhrStub.firstCall.args[0];
+      expect(headers['User-Agent']).to.match(/^yaml-language-server\/unknown \(RedHat\)/);
+    });
+
+    it('should send User-Agent on http:// URIs as well as https://', async () => {
+      process.env.YAML_LANGUAGE_SERVER_VERSION = '2.0.0';
+      await schemaRequestHandler(connection, 'http://example.com/schema.json', [], URI.parse(''), false, testFileSystem, false);
+
+      const { headers } = xhrStub.firstCall.args[0];
+      expect(headers['User-Agent']).to.match(/^yaml-language-server\/2\.0\.0 \(RedHat\)/);
+    });
+
+    it('should preserve Accept-Encoding header alongside User-Agent', async () => {
+      await schemaRequestHandler(connection, 'https://example.com/schema.json', [], URI.parse(''), false, testFileSystem, false);
+
+      const { headers } = xhrStub.firstCall.args[0];
+      expect(headers['Accept-Encoding']).to.equal('gzip, deflate');
+    });
+
+    it('should return the response text on success', async () => {
+      const result = await schemaRequestHandler(
+        connection,
+        'https://example.com/schema.json',
+        [],
+        URI.parse(''),
+        false,
+        testFileSystem,
+        false
+      );
+      expect(result).to.equal('{"$schema":"http://json-schema.org/draft-07/schema"}');
+    });
+
+    it('should reject with responseText on xhr error', async () => {
+      xhrStub.rejects({ responseText: 'Not Found', status: 404 } as XHRResponse);
+      try {
+        await schemaRequestHandler(
+          connection,
+          'https://example.com/schema.json',
+          [],
+          URI.parse(''),
+          false,
+          testFileSystem,
+          false
+        );
+        expect.fail('Expected promise to be rejected');
+      } catch (err) {
+        expect(err).to.equal('Not Found');
+      }
+    });
+  });
 });