test: add encodeAndAddWellKnownMetadata tests

Signed-off-by: Kevin Viglucci <[email protected]>

Author: viglucci

packages/rsocket-composite-metadata/__tests__/encodeAndAddWellKnownMetadata.ts

@@ -0,0 +1,44 @@
+import {
+  encodeAndAddWellKnownMetadata,
+  WellKnownMimeType,
+} from "rsocket-composite-metadata";
+import { readUInt24BE } from "rsocket-core";
+
+describe("encodeWellKnownMetadataHeader", () => {
+  it("encodes the header as per spec when WellKnownMimeType given", () => {
+    const metadata = encodeAndAddWellKnownMetadata(
+      Buffer.from([]),
+      WellKnownMimeType.MESSAGE_RSOCKET_MIMETYPE,
+      Buffer.from("test")
+    );
+
+    // 122 | 128
+    const maskedId = metadata.readUInt8(0);
+    const length = readUInt24BE(metadata, 1);
+    const value = metadata.slice(4, metadata.length);
+
+    expect(maskedId).toBe(250);
+    expect(length).toBe(4);
+    expect(value.length).toBe(4);
+    expect(value.toString("utf-8")).toBe("test");
+  });
+
+  it("encodes the header as per spec when identifier given", () => {
+    const metadata = encodeAndAddWellKnownMetadata(
+      Buffer.from([]),
+      // MESSAGE_RSOCKET_MIMETYPE
+      122,
+      Buffer.from("test")
+    );
+
+    // 122 | 128
+    const maskedId = metadata.readUInt8(0);
+    const length = readUInt24BE(metadata, 1);
+    const value = metadata.slice(4, metadata.length);
+
+    expect(maskedId).toBe(250);
+    expect(length).toBe(4);
+    expect(value.length).toBe(4);
+    expect(value.toString("utf-8")).toBe("test");
+  });
+});