/
resource-stream.ts
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/
resource-stream.ts
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// Copyright 2019 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
import * as assert from 'assert';
import {describe, it} from 'mocha';
import * as sinon from 'sinon';
import {Transform} from 'stream';
import {ResourceStream} from '../src/resource-stream';
describe('ResourceStream', () => {
const sandbox = sinon.createSandbox();
const config = {
maxApiCalls: -1,
maxResults: -1,
query: {},
};
let requestSpy: sinon.SinonSpy;
let stream: ResourceStream<{}>;
// eslint-disable-next-line no-undef
beforeEach(() => {
requestSpy = sandbox.spy();
stream = new ResourceStream(config, requestSpy);
});
// eslint-disable-next-line no-undef
afterEach(() => {
sandbox.restore();
});
describe('instantiation', () => {
it('should pass the streamingOptions to the constructor', () => {
const highWaterMark = 1;
const options = {
streamOptions: {highWaterMark},
},
stream = new ResourceStream(options, requestSpy);
assert.strictEqual(stream.readableHighWaterMark, highWaterMark);
});
it('should set ended to false', () => {
assert.strictEqual(stream._ended, false);
});
it('should set reading to false', () => {
assert.strictEqual(stream._reading, false);
});
it('should set requestsMade to 0', () => {
assert.strictEqual(stream._requestsMade, 0);
});
it('should localize the first query', () => {
assert.strictEqual(stream._nextQuery, config.query);
});
it('should localize the request function', () => {
assert.strictEqual(stream._requestFn, requestSpy);
});
describe('maxApiCalls', () => {
it('should localize maxApiCalls', () => {
const maxApiCalls = 100;
stream = new ResourceStream({maxApiCalls}, requestSpy);
assert.strictEqual(stream._maxApiCalls, maxApiCalls);
});
it('should set it to Infinity if not specified', () => {
assert.strictEqual(stream._maxApiCalls, Infinity);
});
});
describe('resultsToSend', () => {
it('should localize maxResults as resultsToSend', () => {
const maxResults = 100;
stream = new ResourceStream({maxResults}, requestSpy);
assert.strictEqual(stream._resultsToSend, maxResults);
});
it('should set it to Infinity if not specified', () => {
assert.strictEqual(stream._resultsToSend, Infinity);
});
});
});
describe('end', () => {
it('should set ended to true', () => {
stream.end();
assert.strictEqual(stream._ended, true);
});
it('should call through to super.end', () => {
const stub = sandbox.stub(Transform.prototype, 'end');
stream.end();
assert.strictEqual(stub.callCount, 1);
});
});
describe('_read', () => {
it('should set reading to true', () => {
stream._read();
assert.strictEqual(stream._reading, true);
});
it('should noop if already reading', () => {
stream._read();
stream._read();
assert.strictEqual(requestSpy.callCount, 1);
});
it('should pass in the query options', () => {
stream._read();
const query = requestSpy.lastCall.args[0];
assert.strictEqual(query, config.query);
});
it('should destroy the stream if an error occurs', () => {
const fakeError = new Error('err');
const stub = sandbox.stub(stream, 'destroy').withArgs(fakeError);
stream._read();
const callback = requestSpy.lastCall.args[1];
callback(fakeError);
assert.strictEqual(stub.callCount, 1);
});
it('should cache the next query', () => {
const fakeQuery = {};
stream._read();
const callback = requestSpy.lastCall.args[1];
callback(null, [], fakeQuery);
assert.strictEqual(stream._nextQuery, fakeQuery);
});
it('should adjust the results to send counter', () => {
const maxResults = 100;
const results = [{}, {}];
const expected = maxResults - results.length;
stream = new ResourceStream({maxResults}, requestSpy);
stream._read();
const callback = requestSpy.lastCall.args[1];
callback(null, results);
assert.strictEqual(stream._resultsToSend, expected);
});
it('should push in all the results', () => {
// tslint:disable-next-line ban
const results = Array(20).fill({});
const stub = sandbox.stub(stream, 'push');
stream._read();
const callback = requestSpy.lastCall.args[1];
callback(null, results, {});
assert.strictEqual(stub.callCount, results.length);
results.forEach((result, i) => {
const pushed = stub.getCall(i).args[0];
assert.strictEqual(pushed, result);
});
});
it('should stop pushing results if the stream is ended', () => {
// tslint:disable-next-line ban
const results = Array(20).fill({});
stream.on('data', () => stream.end());
stream._read();
const callback = requestSpy.lastCall.args[1];
callback(null, results, {});
assert.strictEqual(requestSpy.callCount, 1);
});
it('should end the stream if there is no next query', () => {
const stub = sandbox.stub(stream, 'end');
stream._read();
const callback = requestSpy.lastCall.args[1];
callback(null, []);
assert.strictEqual(stub.callCount, 1);
});
it('should end the stream if max results is hit', () => {
const maxResults = 10;
// tslint:disable-next-line ban
const results = Array(maxResults).fill({});
stream = new ResourceStream({maxResults}, requestSpy);
const stub = sandbox.stub(stream, 'end');
stream._read();
const callback = requestSpy.lastCall.args[1];
callback(null, results, {});
assert.strictEqual(stub.callCount, 1);
});
it('should end the stream if max api calls is hit', () => {
const maxApiCalls = 1;
stream = new ResourceStream({maxApiCalls}, requestSpy);
const stub = sandbox.stub(stream, 'end');
stream._read();
const callback = requestSpy.lastCall.args[1];
callback(null, [], {});
assert.strictEqual(stub.callCount, 1);
});
it('should stop reading if the buffer is full', () => {
const clock = sandbox.useFakeTimers();
// tslint:disable-next-line ban
const results = Array(stream.readableHighWaterMark).fill({});
stream._read();
const callback = requestSpy.lastCall.args[1];
callback(null, results, {});
const stub = sandbox.stub(stream, '_read');
clock.runAll();
assert.strictEqual(stub.callCount, 0);
});
it('should stop reading if the stream ended', () => {
const clock = sandbox.useFakeTimers();
stream.on('data', () => stream.end());
stream._read();
const callback = requestSpy.lastCall.args[1];
callback(null, [{}], {});
const stub = sandbox.stub(stream, '_read');
clock.runAll();
assert.strictEqual(stub.callCount, 0);
});
it('should keep reading if not full/ended', () => {
const clock = sandbox.useFakeTimers();
stream._read();
const callback = requestSpy.lastCall.args[1];
callback(null, [{}], {});
const stub = sandbox.stub(stream, '_read');
clock.runAll();
assert.strictEqual(stub.callCount, 1);
});
it('should set reading to false inbetween reads', () => {
stream._read();
const callback = requestSpy.lastCall.args[1];
callback(null, [{}], {});
assert.strictEqual(stream._reading, false);
});
});
});