Pact-JS Core

A wrapper for the Pact CLI Tools.

• Pact-JS Core
  • Installation
    • Do Not Track
  • Which Library/Package should I use?
  • Usage
  • Documentation
    • Set Log Level
    • Mock Servers
      • Create Mock Server
      • List Mock Servers
      • Remove All Mock Servers
      • Start a Mock Server
      • Stop a Mock server
      • Delete a Mock server
      • Check if a Mock server is running
      • Mock Server Events
    • Provider Verification
    • Pact Broker Publishing
    • Pact Broker Deployment Check
    • Stub Servers
      • Create Stub Server
    • Message Pacts
      • Create Message Pacts
        • Example
  • CLI Tools

Installation

npm install @pact-foundation/pact-core --save-dev

Do Not Track

In order to get better statistics as to who is using Pact, we have an anonymous tracking event that triggers when Pact installs for the first time. To respect your privacy, anyone can turn it off by simply adding a 'do not track' flag within their package.json file:

{
 "name": "some-project",
 ...
 "config": {
  "pact_do_not_track": true
 },
 ...
}

Which Library/Package should I use?

TL;DR - you almost always want Pact JS.

* The "I need to run it in the browser" question comes up occasionally. The question is this - for your JS code to be able to make a call to another API, is this dependent on browser-specific code? In most cases, people use tools like React/Angular which have libraries that work on the server and client side, in which case, these tests don't need to run in a browser and could instead be executed in a Node.js environment.

Usage

Simply require the library and call the create function to start the mock service

var pact = require("@pact-foundation/pact-core");
var server = pact.createServer({ port: 9999 });
server.start().then(function() {
 // Do your testing/development here
});

Or if you're using Typescript instead of plain old Javascript

import pact from "@pact-foundation/pact-core";
const server = pact.createServer({ port: 9999 });
server.start().then(() => {
 // Do your testing/development here
});

Or you can also use the CLI

$# pact mock --port 9999

To see the list commands possible with the CLI, simply ask for help $# pact --help

Documentation

Set Log Level

var pact = require("@pact-foundation/pact-core");
pact.logLevel("debug");

Mock Servers

Mock servers are used by Pact to record interactions and create pact contracts.

Create Mock Server

var pact = require('@pact-foundation/pact-core');
var server = pact.createServer({
 ...
});

Options:

List Mock Servers

If you ever need to see which servers are currently created.

var pact = require("@pact-foundation/pact-core");
var servers = pact.listServers();
console.log(JSON.stringify(servers));

Remove All Mock Servers

Remove all servers once you're done with them in one fell swoop.

var pact = require("@pact-foundation/pact-core");
pact.removeAllServers();

Start a Mock Server

Start the current server.

var pact = require("@pact-foundation/pact-core");
pact.createServer()
 .start()
 .then(function() {
  // Do something after it started
 });

Stop a Mock server

Stop the current server.

var pact = require("@pact-foundation/pact-core");
pact.createServer()
 .stop()
 .then(function() {
  // Do something after it stopped
 });

Delete a Mock server

Stop the current server and deletes it from the list.

var pact = require("@pact-foundation/pact-core");
pact.createServer()
 .delete()
 .then(function() {
  // Do something after it was killed
 });

Check if a Mock server is running

var pact = require("@pact-foundation/pact-core");
pact.createServer().running;

Mock Server Events

There's 3 different events available, 'start', 'stop' and 'delete'. They can be listened to the same way as an EventEmitter.

var pact = require("@pact-foundation/pact-core");
var server = pact.createServer();
server.on("start", function() {
 console.log("started");
});
server.on("stop", function() {
 console.log("stopped");
});
server.on("delete", function() {
 console.log("deleted");
});

Provider Verification

Read more about Verify Pacts.

var pact = require('@pact-foundation/pact-core');

pact.verifyPacts({
 ...
});

Options:

The consumer version selector looks like this:

ConsumerVersionSelector {
  tag?: string;
  latest?: boolean;
  consumer?: string;
  deployedOrReleased?: boolean;
  deployed?: boolean; 
  released?: boolean; 
  environment?: string;
  fallbackTag?: string;
  branch?: string;
  mainBranch?: boolean;
  matchingBranch?: boolean;
}

See the Pact Broker documentation on selectors for more information.

Pact Broker Publishing

var pact = require('@pact-foundation/pact-core');
var opts = {
 ...
};

pact.publishPacts(opts).then(function () {
 // do something
});

Options:

Pact Broker Deployment Check

var pact = require('@pact-foundation/pact-core');
var opts = {
 ...
};

pact.canDeploy(opts)
 .then(function (result) {
  // You can deploy this
    // If output is not specified or is json, result describes the result of the check.
    // If outout is 'table', it is the human readable string returned by the check
 })
 .catch(function(error) {
  // You can't deploy this
    // if output is not specified, or is json, error will be an object describing
    // the result of the check (if the check failed),
    // if output is 'table', then the error will be a string describing the output from the binary,

    // In both cases, `error` will be an Error object if something went wrong during the check.
 });

Options:

Stub Servers

Stub servers create runnable APIs from existing pact files.

The interface is comparable to the Mock Server API.

Create Stub Server

var pact = require('@pact-foundation/pact-core');
var server = pact.createStub({
 ...
});

Options:

Message Pacts

Create Message Pacts

var pact = require('@pact-foundation/pact-core');
var message = pact.createMessage({
 ...
});

Options:

Example

const messageFactory = messageFactory({
 consumer: "consumer",
 provider: "provider",
 dir: dirname(`${__filename}/pacts`),
 content: `{
  "description": "a test mesage",
  "content": {
   "name": "Mary"
  }
 }`
});

messageFactory.createMessage();

CLI Tools

This package also comes with the Pact Standalone Tools available as linked binaries in the standard NPM installation directory (e..g. ./node_modules/.bin).

This means you may call them direct from scripts in your package json, for example:

"scripts": {
  "pactPublish": "pact-broker publish ./pacts --consumer-app-version=$\(git describe\) --broker-base-url=$BROKER_BASE_URL --broker-username=$BROKER_USERNAME --broker-password=BROKER_PASSWORD"`
}
These are available in circumstances where `pact-core` has not yet implemented a feature or access via JavaScript APIs is not desirable. To run the binaries is as simple as the following:

*Example can-i-deploy check*:
```sh
./node_modules/.bin/pact-broker can-i-deploy --pacticipant "Banana Service" --broker-base-url https://test.pact.dius.com.au --latest --broker-username dXfltyFMgNOFZAxr8io9wJ37iUpY42M --broker-password O5AIZWxelWbLvqMd8PkAVycBJh2Psyg1

Computer says no ¯\_(ツ)_/¯

CONSUMER       | C.VERSION | PROVIDER       | P.VERSION | SUCCESS?
---------------|-----------|----------------|-----------|---------
Banana Service | 1.0.0     | Fofana Service | 1.0.0     | false

The verification between the latest version of Banana Service (1.0.0) and version 1.0.0 of Fofana Service failed

The following are the binaries currently made available:

• pact-mock-service
• pact-broker
• pact-stub-service
• pact-message
• pact-provider-verifier
• pact

Windows Issues

Enable Long Paths

Windows has a default path length limit of 260 causing issues with projects that are nested deep inside several directory and with how npm handles node_modules directory structures. To fix this issue, please enable Windows Long Paths in the registry by running regedit.exe, find the key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem\LongPathsEnabled and change the value from 0 to 1, then reboot your computer. Pact should now work as it should, if not, please raise an issue on github.

Contributing

To develop this project, simply install the dependencies with npm install --ignore-scripts, and run npm run watch to for continual development, linting and testing when a source file changes.

Testing

Running npm test will execute the tests that has the *.spec.js pattern.

Questions?

Please search for potential answers or post question on our official Pact StackOverflow.