test: add unit tests for cursor response ctor

Author: nbbeeken

test/unit/cmap/wire_protocol/responses.test.ts

@@ -1,7 +1,15 @@
 import { expect } from 'chai';
 import * as sinon from 'sinon';
 
-import { BSON, MongoDBResponse, OnDemandDocument } from '../../../mongodb';
+import {
+  BSON,
+  BSONError,
+  CursorResponse,
+  Int32,
+  MongoDBResponse,
+  MongoUnexpectedServerResponseError,
+  OnDemandDocument
+} from '../../../mongodb';
 
 describe('class MongoDBResponse', () => {
   it('is a subclass of OnDemandDocument', () => {
@@ -76,3 +84,90 @@ describe('class MongoDBResponse', () => {
     });
   });
 });
+
+describe('class CursorResponse', () => {
+  describe('constructor()', () => {
+    it('throws if input does not contain cursor embedded document', () => {
+      expect(() => new CursorResponse(BSON.serialize({ ok: 1 }))).to.throw(BSONError);
+    });
+
+    it('throws if input does not contain cursor.id int64', () => {
+      expect(() => new CursorResponse(BSON.serialize({ ok: 1, cursor: {} }))).to.throw(BSONError);
+    });
+
+    it('sets namespace to null if input does not contain cursor.ns', () => {
+      expect(new CursorResponse(BSON.serialize({ ok: 1, cursor: { id: 0n, firstBatch: [] } })).ns)
+        .to.be.null;
+    });
+
+    it('throws if input does not contain firstBatch nor nextBatch', () => {
+      expect(
+        () => new CursorResponse(BSON.serialize({ ok: 1, cursor: { id: 0n, batch: [] } }))
+      ).to.throw(MongoUnexpectedServerResponseError);
+    });
+
+    it('reports a length equal to the batch', () => {
+      expect(
+        new CursorResponse(BSON.serialize({ ok: 1, cursor: { id: 0n, nextBatch: [1, 2, 3] } }))
+      ).to.have.lengthOf(3);
+    });
+  });
+
+  describe('shift()', () => {
+    let response;
+
+    beforeEach(async function () {
+      response = new CursorResponse(
+        BSON.serialize({
+          ok: 1,
+          cursor: { id: 0n, nextBatch: [{ _id: 1 }, { _id: 2 }, { _id: 3 }] }
+        })
+      );
+    });
+
+    it('returns a document from the batch', () => {
+      expect(response.shift()).to.deep.equal({ _id: 1 });
+      expect(response.shift()).to.deep.equal({ _id: 2 });
+      expect(response.shift()).to.deep.equal({ _id: 3 });
+      expect(response.shift()).to.deep.equal(null);
+    });
+
+    it('passes BSON options to deserialization', () => {
+      expect(response.shift({ promoteValues: false })).to.deep.equal({ _id: new Int32(1) });
+      expect(response.shift({ promoteValues: true })).to.deep.equal({ _id: 2 });
+      expect(response.shift({ promoteValues: false })).to.deep.equal({ _id: new Int32(3) });
+      expect(response.shift()).to.deep.equal(null);
+    });
+  });
+
+  describe('clear()', () => {
+    let response;
+
+    beforeEach(async function () {
+      response = new CursorResponse(
+        BSON.serialize({
+          ok: 1,
+          cursor: { id: 0n, nextBatch: [{ _id: 1 }, { _id: 2 }, { _id: 3 }] }
+        })
+      );
+    });
+
+    it('makes length equal to 0', () => {
+      expect(response.clear()).to.be.undefined;
+      expect(response).to.have.lengthOf(0);
+    });
+
+    it('makes shift return null', () => {
+      expect(response.clear()).to.be.undefined;
+      expect(response.shift()).to.be.null;
+    });
+  });
+
+  describe('pushMany()', () =>
+    it('throws unsupported error', () =>
+      expect(CursorResponse.prototype.pushMany).to.throw(/Unsupported/i)));
+
+  describe('push()', () =>
+    it('throws unsupported error', () =>
+      expect(CursorResponse.prototype.push).to.throw(/Unsupported/i)));
+});