Basic setup for contract testing

This commit contains a basic consumer side test setup.
It is still a draft but sets up the needed folder structure.

.eslintignore

@@ -9,3 +9,4 @@
 /sitespeed-result/
 /fixtures/**/*.graphql
 spec/fixtures/**/*.graphql
+**/contracts/consumer/

qa/Gemfile

@@ -35,6 +35,8 @@ gem 'confiner', '~> 0.2'
 gem 'chemlab', '~> 0.9'
 gem 'chemlab-library-www-gitlab-com', '~> 0.1'
 
+gem "pact", "~> 1.12"
+
 gem 'deprecation_toolkit', '~> 1.5.1', require: false
 
 group :development do

qa/Gemfile.lock

@@ -28,6 +28,7 @@ GEM
       require_all (>= 2, < 4)
       uuid (>= 2.3, < 3)
     ast (2.4.2)
+    awesome_print (1.9.2)
     binding_ninja (0.2.3)
     builder (3.2.4)
     byebug (9.1.0)
@@ -91,6 +92,8 @@ GEM
     ffi-compiler (1.0.1)
       ffi (>= 1.0.0)
       rake
+    filelock (1.1.1)
+    find_a_port (1.0.1)
     fog-core (2.1.0)
       builder
       excon (~> 0.58)
@@ -173,6 +176,7 @@ GEM
       concurrent-ruby (~> 1.0)
     ice_nine (0.11.2)
     influxdb-client (1.17.0)
+    json (2.6.1)
     jwt (2.3.0)
     knapsack (4.0.0)
       rake
@@ -205,6 +209,29 @@ GEM
       sawyer (~> 0.8.0, >= 0.5.3)
     oj (3.13.11)
     os (1.1.4)
+    pact (1.59.0)
+      pact-mock_service (~> 3.0, >= 3.3.1)
+      pact-support (~> 1.15)
+      rack-test (>= 0.6.3, < 2.0.0)
+      rspec (~> 3.0)
+      term-ansicolor (~> 1.0)
+      thor (>= 0.20, < 2.0)
+      webrick (~> 1.3)
+    pact-mock_service (3.6.2)
+      filelock (~> 1.1)
+      find_a_port (~> 1.0.1)
+      json
+      pact-support (~> 1.12, >= 1.12.0)
+      rack (~> 2.0)
+      rspec (>= 2.14)
+      term-ansicolor (~> 1.0)
+      thor (>= 0.19, < 2.0)
+      webrick (~> 1.3)
+    pact-support (1.15.1)
+      awesome_print (~> 1.1)
+      randexp (~> 0.1.7)
+      rspec (>= 2.14)
+      term-ansicolor (~> 1.0)
     parallel (1.19.2)
     parallel_tests (2.29.0)
       parallel
@@ -228,6 +255,7 @@ GEM
       rack (>= 1.0, < 3)
     rainbow (3.0.0)
     rake (13.0.6)
+    randexp (0.1.7)
     regexp_parser (2.1.1)
     representable (3.1.1)
       declarative (< 0.1.0)
@@ -282,12 +310,18 @@ GEM
       jwt (>= 1.5, < 3.0)
       multi_json (~> 1.10)
     slack-notifier (2.4.0)
+    sync (0.5.0)
     systemu (2.6.5)
     table_print (1.5.7)
+    term-ansicolor (1.7.1)
+      tins (~> 1.0)
     terminal-table (3.0.2)
       unicode-display_width (>= 1.1.1, < 3)
+    thor (1.2.1)
     thread_safe (0.3.6)
     timecop (0.9.1)
+    tins (1.31.0)
+      sync
     trailblazer-option (0.1.2)
     tzinfo (2.0.4)
       concurrent-ruby (~> 1.0)
@@ -337,6 +371,7 @@ DEPENDENCIES
   influxdb-client (~> 1.17)
   knapsack (~> 4.0)
   octokit (~> 4.21)
+  pact (~> 1.12)
   parallel (~> 1.19)
   parallel_tests (~> 2.29)
   pry-byebug (~> 3.5.1)

qa/bin/contract

+#!/usr/bin/env ruby
+# frozen_string_literal: true
+
+require 'rake'
+
+host = ARGV.shift
+ENV['CONTRACT_HOST'] ||= host
+
+list = []
+
+loop do
+  keyword = ARGV.shift
+  case keyword
+  when '--mr'
+    ENV['CONTRACT_MR'] ||= ARGV.shift
+    list.push 'test:merge_request'
+  else
+    break
+  end
+end
+
+app = Rake.application
+
+Dir.chdir('contracts/provider') do
+  app.init
+  app.add_import 'Rakefile'
+  app.load_rakefile
+
+  list.each do |element|
+    app[element].invoke
+  end
+end

qa/contracts/.gitignore

+logs/
+consumer/node_modules

qa/contracts/consumer/.node-version

+14.17.5

qa/contracts/consumer/endpoints/merge_request.js

+'use strict';
+
+const axios = require('axios');
+
+exports.getMetadata = (endpoint) => {
+  const url = endpoint.url;
+
+  return axios
+    .request({
+      method: 'GET',
+      baseURL: url,
+      url: '/diffs_metadata.json',
+      headers: { Accept: '*/*' },
+    })
+    .then((response) => response.data);
+};
+
+exports.getDiscussions = (endpoint) => {
+  const url = endpoint.url;
+
+  return axios
+    .request({
+      method: 'GET',
+      baseURL: url,
+      url: '/discussions.json',
+      headers: { Accept: '*/*' },
+    })
+    .then((response) => response.data);
+};
+
+exports.getDiffs = (endpoint) => {
+  const url = endpoint.url;
+
+  return axios
+    .request({
+      method: 'GET',
+      baseURL: url,
+      url: '/diffs_batch.json?page=0',
+      headers: { Accept: '*/*' },
+    })
+    .then((response) => response.data);
+};

qa/contracts/consumer/fixtures/diffs.fixture.js

+'use strict';
+
+const { Matchers } = require('@pact-foundation/pact');
+
+const body = {
+  diff_files: Matchers.eachLike({
+    content_sha: Matchers.string('b0c94059db75b2473d616d4b1fde1a77533355a3'),
+    submodule: Matchers.boolean(false),
+    edit_path: Matchers.string('/gitlab-qa-bot/...'),
+    ide_edit_path: Matchers.string('/gitlab-qa-bot/...'),
+    old_path_html: Matchers.string('Gemfile'),
+    new_path_html: Matchers.string('Gemfile'),
+    blob: {
+      id: Matchers.string('855071bb3928d140764885964f7be1bb3e582495'),
+      path: Matchers.string('Gemfile'),
+      name: Matchers.string('Gemfile'),
+      mode: Matchers.string('1234567'),
+      readable_text: Matchers.boolean(true),
+      icon: Matchers.string('doc-text'),
+    },
+    can_modify_blob: Matchers.boolean(false),
+    file_identifier_hash: Matchers.string('67d82b8716a5b6c52c7abf0b2cd99c7594ed3587'),
+    file_hash: Matchers.string('67d82b8716a5b6c52c7abf0b2cd99c7594ed3587'),
+    file_path: Matchers.string('Gemfile'),
+    old_path: Matchers.string('Gemfile'),
+    new_path: Matchers.string('Gemfile'),
+    new_file: Matchers.boolean(false),
+    renamed_file: Matchers.boolean(false),
+    deleted_file: Matchers.boolean(false),
+    diff_refs: {
+      base_sha: Matchers.string('67d82b8716a5b6c52c7abf0b2cd99c7594ed3587'),
+      start_sha: Matchers.string('67d82b8716a5b6c52c7abf0b2cd99c7594ed3587'),
+      head_sha: Matchers.string('67d82b8716a5b6c52c7abf0b2cd99c7594ed3587'),
+    },
+    mode_changed: Matchers.boolean(false),
+    a_mode: Matchers.string('123456'),
+    b_mode: Matchers.string('123456'),
+    viewer: {
+      name: Matchers.string('text'),
+      collapsed: Matchers.boolean(false),
+    },
+    old_size: Matchers.integer(2288),
+    new_size: Matchers.integer(2288),
+    added_lines: Matchers.integer(1),
+    removed_lines: Matchers.integer(1),
+    load_collapsed_diff_url: Matchers.string('/gitlab-qa-bot/...'),
+    view_path: Matchers.string('/gitlab-qa-bot/...'),
+    context_lines_path: Matchers.string('/gitlab-qa-bot/...'),
+    highlighted_diff_lines: Matchers.eachLike({
+      // The following values can also be null which is not supported
+      //line_code: Matchers.string('de3150c01c3a946a6168173c4116741379fe3579_1_1'),
+      //old_line: Matchers.integer(1),
+      //new_line: Matchers.integer(1),
+      text: Matchers.string('source'),
+      rich_text: Matchers.string('<span></span>'),
+      can_receive_suggestion: Matchers.boolean(true),
+    }),
+    is_fully_expanded: Matchers.boolean(false),
+  }),
+  pagination: {
+    total_pages: Matchers.integer(1),
+  },
+};
+
+const Diffs = {
+  body: Matchers.extractPayload(body),
+
+  success: {
+    status: 200,
+    headers: {
+      'Content-Type': 'application/json; charset=utf-8',
+    },
+    body: body,
+  },
+
+  request: {
+    uponReceiving: 'a request for diff lines',
+    withRequest: {
+      method: 'GET',
+      path: '/diffs_batch.json',
+      headers: {
+        Accept: '*/*',
+      },
+      query: 'page=0',
+    },
+  },
+};
+
+exports.Diffs = Diffs;

qa/contracts/consumer/fixtures/discussions.fixture.js

+'use strict';
+
+const { Matchers } = require('@pact-foundation/pact');
+
+const body = Matchers.eachLike({
+  id: Matchers.string('fd73763cbcbf7b29eb8765d969a38f7d735e222a'),
+  reply_id: Matchers.string('fd73763cbcbf7b29eb8765d969a38f7d735e222a'),
+  project_id: Matchers.integer(6954442),
+  confidential: Matchers.boolean(false),
+  diff_discussion: Matchers.boolean(false),
+  expanded: Matchers.boolean(false),
+  for_commit: Matchers.boolean(false),
+  individual_note: Matchers.boolean(true),
+  resolvable: Matchers.boolean(false),
+  resolved_by_push: Matchers.boolean(false),
+  notes: Matchers.eachLike({
+    id: Matchers.string('76489845'),
+    author: {
+      id: Matchers.integer(1675733),
+      username: Matchers.string('gitlab-qa-bot'),
+      name: Matchers.string('gitlab-qa-bot'),
+      state: Matchers.string('active'),
+      avatar_url: Matchers.string(
+        'https://secure.gravatar.com/avatar/8355ad0f2761367fae6b9c4fe80994b9?s=80&d=identicon',
+      ),
+      show_status: Matchers.boolean(false),
+      path: Matchers.string('/gitlab-qa-bot'),
+    },
+    created_at: Matchers.iso8601DateTimeWithMillis('2022-02-22T07:06:55.038Z'),
+    updated_at: Matchers.iso8601DateTimeWithMillis('2022-02-22T07:06:55.038Z'),
+    system: Matchers.boolean(false),
+    noteable_id: Matchers.integer(8333422),
+    noteable_type: Matchers.string('MergeRequest'),
+    resolvable: Matchers.boolean(false),
+    resolved: Matchers.boolean(true),
+    confidential: Matchers.boolean(false),
+    noteable_iid: Matchers.integer(1),
+    note: Matchers.string('This is a test comment'),
+    note_html: Matchers.string(
+      '<p data-sourcepos="1:1-1:22" dir="auto">This is a test comment</p>',
+    ),
+    current_user: {
+      can_edit: Matchers.boolean(true),
+      can_award_emoji: Matchers.boolean(true),
+      can_resolve: Matchers.boolean(false),
+      can_resolve_discussion: Matchers.boolean(false),
+    },
+    is_noteable_author: Matchers.boolean(true),
+    discussion_id: Matchers.string('fd73763cbcbf7b29eb8765d969a38f7d735e222a'),
+    emoji_awardable: Matchers.boolean(true),
+    report_abuse_path: Matchers.string('/gitlab-qa-bot/...'),
+    noteable_note_url: Matchers.string('https://staging.gitlab.com/gitlab-qa-bot/...'),
+    cached_markdown_version: Matchers.integer(1900552),
+    human_access: Matchers.string('Maintainer'),
+    is_contributor: Matchers.boolean(false),
+    project_name: Matchers.string('contract-testing'),
+    path: Matchers.string('/gitlab-qa-bot/...'),
+  }),
+  resolved: Matchers.boolean(true),
+});
+
+const Discussions = {
+  body: Matchers.extractPayload(body),
+
+  success: {
+    status: 200,
+    headers: {
+      'Content-Type': 'application/json; charset=utf-8',
+    },
+    body: body,
+  },
+
+  request: {
+    uponReceiving: 'a request for discussions',
+    withRequest: {
+      method: 'GET',
+      path: '/discussions.json',
+      headers: {
+        Accept: '*/*',
+      },
+    },
+  },
+};
+
+exports.Discussions = Discussions;

qa/contracts/consumer/fixtures/metadata.fixture.js

+'use strict';
+
+const { Matchers } = require('@pact-foundation/pact');
+
+const body = {
+  real_size: Matchers.string('1'),
+  size: Matchers.integer(1),
+  branch_name: Matchers.string('testing-branch-1'),
+  source_branch_exists: Matchers.boolean(true),
+  target_branch_name: Matchers.string('master'),
+  merge_request_diff: {
+    created_at: Matchers.iso8601DateTimeWithMillis('2022-02-17T11:47:08.804Z'),
+    commits_count: Matchers.integer(1),
+    latest: Matchers.boolean(true),
+    short_commit_sha: Matchers.string('aee1ffec'),
+    base_version_path: Matchers.string(
+      '/gitlab-qa-bot/contract-testing/-/merge_requests/1/diffs?diff_id=10581773',
+    ),
+    head_version_path: Matchers.string(
+      '/gitlab-qa-bot/contract-testing/-/merge_requests/1/diffs?diff_head=true',
+    ),
+    version_path: Matchers.string(
+      '/gitlab-qa-bot/contract-testing/-/merge_requests/1/diffs?diff_id=10581773',
+    ),
+    compare_path: Matchers.string(
+      '/gitlab-qa-bot/contract-testing/-/merge_requests/1/diffs?diff_id=10581773&start_sha=aee1ffec2299c0cfb17c8821e931339b73a3759f',
+    ),
+  },
+  latest_diff: Matchers.boolean(true),
+  latest_version_path: Matchers.string('/gitlab-qa-bot/contract-testing/-/merge_requests/1/diffs'),
+  added_lines: Matchers.integer(1),
+  removed_lines: Matchers.integer(1),
+  render_overflow_warning: Matchers.boolean(false),
+  email_patch_path: Matchers.string('/gitlab-qa-bot/contract-testing/-/merge_requests/1.patch'),
+  plain_diff_path: Matchers.string('/gitlab-qa-bot/contract-testing/-/merge_requests/1.diff'),
+  merge_request_diffs: Matchers.eachLike({
+    commits_count: Matchers.integer(1),
+    latest: Matchers.boolean(true),
+    short_commit_sha: Matchers.string('aee1ffec'),
+    base_version_path: Matchers.string(
+      '/gitlab-qa-bot/contract-testing/-/merge_requests/1/diffs?diff_id=10581773',
+    ),
+    head_version_path: Matchers.string(
+      '/gitlab-qa-bot/contract-testing/-/merge_requests/1/diffs?diff_head=true',
+    ),
+    version_path: Matchers.string(
+      '/gitlab-qa-bot/contract-testing/-/merge_requests/1/diffs?diff_id=10581773',
+    ),
+    compare_path: Matchers.string(
+      '/gitlab-qa-bot/contract-testing/-/merge_requests/1/diffs?diff_id=10581773&start_sha=aee1ffec2299c0cfb17c8821e931339b73a3759f',
+    ),
+  }),
+  definition_path_prefix: Matchers.string(
+    '/gitlab-qa-bot/contract-testing/-/blob/aee1ffec2299c0cfb17c8821e931339b73a3759f',
+  ),
+  diff_files: Matchers.eachLike({
+    added_lines: Matchers.integer(1),
+    removed_lines: Matchers.integer(1),
+    new_path: Matchers.string('Gemfile'),
+    old_path: Matchers.string('Gemfile'),
+    new_file: Matchers.boolean(false),
+    deleted_file: Matchers.boolean(false),
+    submodule: Matchers.boolean(false),
+    file_identifier_hash: Matchers.string('67d82b8716a5b6c52c7abf0b2cd99c7594ed3587'),
+    file_hash: Matchers.string('de3150c01c3a946a6168173c4116741379fe3579'),
+  }),
+  has_conflicts: Matchers.boolean(false),
+  can_merge: Matchers.boolean(false),
+  project_path: Matchers.string('gitlab-qa-bot/contract-testing'),
+  project_name: Matchers.string('contract-testing'),
+};
+
+const Metadata = {
+  body: Matchers.extractPayload(body),
+
+  success: {
+    status: 200,
+    headers: {
+      'Content-Type': 'application/json; charset=utf-8',
+    },
+    body: body,
+  },
+
+  request: {
+    uponReceiving: 'a request for Metadata',
+    withRequest: {
+      method: 'GET',
+      path: '/diffs_metadata.json',
+      headers: {
+        Accept: '*/*',
+      },
+    },
+  },
+};
+
+exports.Metadata = Metadata;

qa/contracts/consumer/package.json

+{
+  "name": "consumer",
+  "version": "1.0.0",
+  "description": "consumer side contract testing",
+  "license": "MIT",
+  "repository": "https://gitlab.com/gitlab-org/gitlab.git",
+  "dependencies": {
+    "@pact-foundation/pact": "^9.17.2",
+    "axios": "^0.26.0",
+    "jest": "^27.5.1",
+    "jest-pact": "^0.9.1",
+    "prettier": "^2.5.1"
+  },
+  "scripts": {
+    "test": "jest specs/ --runInBand"
+  }
+}

qa/contracts/consumer/specs/diffs.spec.js

+'use strict';
+
+const { pactWith } = require('jest-pact');
+
+const { Diffs } = require('../fixtures/diffs.fixture');
+const { getDiffs } = require('../endpoints/merge_request');
+
+pactWith(
+  {
+    consumer: 'Merge Request Page',
+    provider: 'Merge Request Diffs Endpoint',
+    log: '../logs/consumer.log',
+    dir: '../contracts',
+  },
+
+  (provider) => {
+    describe('Diffs Endpoint', () => {
+      beforeEach(() => {
+        const interaction = {
+          ...Diffs.request,
+          willRespondWith: Diffs.success,
+        };
+        return provider.addInteraction(interaction);
+      });
+
+      it('return a successful body', () => {
+        return getDiffs({
+          url: provider.mockService.baseUrl,
+        }).then((diffs) => {
+          expect(diffs).toEqual(Diffs.body);
+        });
+      });
+    });
+  },
+);

qa/contracts/consumer/specs/discussions.spec.js

+'use strict';
+
+const { pactWith } = require('jest-pact');
+
+const { Discussions } = require('../fixtures/discussions.fixture');
+const { getDiscussions } = require('../endpoints/merge_request');
+
+pactWith(
+  {
+    consumer: 'Merge Request Page',
+    provider: 'Merge Request Discussions Endpoint',
+    log: '../logs/consumer.log',
+    dir: '../contracts',
+  },
+
+  (provider) => {
+    describe('Discussions Endpoint', () => {
+      beforeEach(() => {
+        const interaction = {
+          ...Discussions.request,
+          willRespondWith: Discussions.success,
+        };
+        return provider.addInteraction(interaction);
+      });
+
+      it('return a successful body', () => {
+        return getDiscussions({
+          url: provider.mockService.baseUrl,
+        }).then((discussions) => {
+          expect(discussions).toEqual(Discussions.body);
+        });
+      });
+    });
+  },
+);

qa/contracts/consumer/specs/metadata.spec.js

+'use strict';
+
+const { pactWith } = require('jest-pact');
+
+const { Metadata } = require('../fixtures/metadata.fixture');
+const { getMetadata } = require('../endpoints/merge_request');
+
+pactWith(
+  {
+    consumer: 'Merge Request Page',
+    provider: 'Merge Request Metadata Endpoint',
+    log: '../logs/consumer.log',
+    dir: '../contracts',
+  },
+
+  (provider) => {
+    describe('Metadata Endpoint', () => {
+      beforeEach(() => {
+        const interaction = {
+          ...Metadata.request,
+          willRespondWith: Metadata.success,
+        };
+        return provider.addInteraction(interaction);
+      });
+
+      it('return a successful body', () => {
+        return getMetadata({
+          url: provider.mockService.baseUrl,
+        }).then((metadata) => {
+          expect(metadata).toEqual(Metadata.body);
+        });
+      });
+    });
+  },
+);

qa/contracts/contracts/merge_request_page-merge_request_diffs_endpoint.json

+{
+  "consumer": {
+    "name": "Merge Request Page"
+  },
+  "provider": {
+    "name": "Merge Request Diffs Endpoint"
+  },
+  "interactions": [
+    {
+      "description": "a request for diff lines",
+      "request": {
+        "method": "GET",
+        "path": "/diffs_batch.json",
+        "query": "page=0",
+        "headers": {
+          "Accept": "*/*"
+        }
+      },
+      "response": {
+        "status": 200,
+        "headers": {
+          "Content-Type": "application/json; charset=utf-8"
+        },
+        "body": {
+          "diff_files": [
+            {
+              "content_sha": "b0c94059db75b2473d616d4b1fde1a77533355a3",
+              "submodule": false,
+              "edit_path": "/gitlab-qa-bot/...",
+              "ide_edit_path": "/gitlab-qa-bot/...",
+              "old_path_html": "Gemfile",
+              "new_path_html": "Gemfile",
+              "blob": {
+                "id": "855071bb3928d140764885964f7be1bb3e582495",
+                "path": "Gemfile",
+                "name": "Gemfile",
+                "mode": "1234567",
+                "readable_text": true,
+                "icon": "doc-text"
+              },
+              "can_modify_blob": false,
+              "file_identifier_hash": "67d82b8716a5b6c52c7abf0b2cd99c7594ed3587",
+              "file_hash": "67d82b8716a5b6c52c7abf0b2cd99c7594ed3587",
+              "file_path": "Gemfile",
+              "old_path": "Gemfile",
+              "new_path": "Gemfile",
+              "new_file": false,
+              "renamed_file": false,
+              "deleted_file": false,
+              "diff_refs": {
+                "base_sha": "67d82b8716a5b6c52c7abf0b2cd99c7594ed3587",
+                "start_sha": "67d82b8716a5b6c52c7abf0b2cd99c7594ed3587",
+                "head_sha": "67d82b8716a5b6c52c7abf0b2cd99c7594ed3587"
+              },
+              "mode_changed": false,
+              "a_mode": "123456",
+              "b_mode": "123456",
+              "viewer": {
+                "name": "text",
+                "collapsed": false
+              },
+              "old_size": 2288,
+              "new_size": 2288,
+              "added_lines": 1,
+              "removed_lines": 1,
+              "load_collapsed_diff_url": "/gitlab-qa-bot/...",
+              "view_path": "/gitlab-qa-bot/...",
+              "context_lines_path": "/gitlab-qa-bot/...",
+              "highlighted_diff_lines": [
+                {
+                  "text": "source",
+                  "rich_text": "<span></span>",
+                  "can_receive_suggestion": true
+                }
+              ],
+              "is_fully_expanded": false
+            }
+          ],
+          "pagination": {
+            "total_pages": 1
+          }
+        },
+        "matchingRules": {
+          "$.body.diff_files": {
+            "min": 1
+          },
+          "$.body.diff_files[*].*": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].content_sha": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].submodule": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].edit_path": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].ide_edit_path": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].old_path_html": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].new_path_html": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].blob.id": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].blob.path": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].blob.name": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].blob.mode": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].blob.readable_text": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].blob.icon": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].can_modify_blob": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].file_identifier_hash": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].file_hash": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].file_path": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].old_path": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].new_path": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].new_file": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].renamed_file": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].deleted_file": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].diff_refs.base_sha": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].diff_refs.start_sha": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].diff_refs.head_sha": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].mode_changed": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].a_mode": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].b_mode": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].viewer.name": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].viewer.collapsed": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].old_size": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].new_size": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].added_lines": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].removed_lines": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].load_collapsed_diff_url": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].view_path": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].context_lines_path": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].highlighted_diff_lines": {
+            "min": 1
+          },
+          "$.body.diff_files[*].highlighted_diff_lines[*].*": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].highlighted_diff_lines[*].text": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].highlighted_diff_lines[*].rich_text": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].highlighted_diff_lines[*].can_receive_suggestion": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].is_fully_expanded": {
+            "match": "type"
+          },
+          "$.body.pagination.total_pages": {
+            "match": "type"
+          }
+        }
+      }
+    }
+  ],
+  "metadata": {
+    "pactSpecification": {
+      "version": "2.0.0"
+    }
+  }
+}
\ No newline at end of file

qa/contracts/contracts/merge_request_page-merge_request_discussions_endpoint.json

+{
+  "consumer": {
+    "name": "Merge Request Page"
+  },
+  "provider": {
+    "name": "Merge Request Discussions Endpoint"
+  },
+  "interactions": [
+    {
+      "description": "a request for discussions",
+      "request": {
+        "method": "GET",
+        "path": "/discussions.json",
+        "headers": {
+          "Accept": "*/*"
+        }
+      },
+      "response": {
+        "status": 200,
+        "headers": {
+          "Content-Type": "application/json; charset=utf-8"
+        },
+        "body": [
+          {
+            "id": "fd73763cbcbf7b29eb8765d969a38f7d735e222a",
+            "reply_id": "fd73763cbcbf7b29eb8765d969a38f7d735e222a",
+            "project_id": 6954442,
+            "confidential": false,
+            "diff_discussion": false,
+            "expanded": false,
+            "for_commit": false,
+            "individual_note": true,
+            "resolvable": false,
+            "resolved_by_push": false,
+            "notes": [
+              {
+                "id": "76489845",
+                "author": {
+                  "id": 1675733,
+                  "username": "gitlab-qa-bot",
+                  "name": "gitlab-qa-bot",
+                  "state": "active",
+                  "avatar_url": "https://secure.gravatar.com/avatar/8355ad0f2761367fae6b9c4fe80994b9?s=80&d=identicon",
+                  "show_status": false,
+                  "path": "/gitlab-qa-bot"
+                },
+                "created_at": "2022-02-22T07:06:55.038Z",
+                "updated_at": "2022-02-22T07:06:55.038Z",
+                "system": false,
+                "noteable_id": 8333422,
+                "noteable_type": "MergeRequest",
+                "resolvable": false,
+                "resolved": true,
+                "confidential": false,
+                "noteable_iid": 1,
+                "note": "This is a test comment",
+                "note_html": "<p data-sourcepos=\"1:1-1:22\" dir=\"auto\">This is a test comment</p>",
+                "current_user": {
+                  "can_edit": true,
+                  "can_award_emoji": true,
+                  "can_resolve": false,
+                  "can_resolve_discussion": false
+                },
+                "is_noteable_author": true,
+                "discussion_id": "fd73763cbcbf7b29eb8765d969a38f7d735e222a",
+                "emoji_awardable": true,
+                "report_abuse_path": "/gitlab-qa-bot/...",
+                "noteable_note_url": "https://staging.gitlab.com/gitlab-qa-bot/...",
+                "cached_markdown_version": 1900552,
+                "human_access": "Maintainer",
+                "is_contributor": false,
+                "project_name": "contract-testing",
+                "path": "/gitlab-qa-bot/..."
+              }
+            ],
+            "resolved": true
+          }
+        ],
+        "matchingRules": {
+          "$.body": {
+            "min": 1
+          },
+          "$.body[*].*": {
+            "match": "type"
+          },
+          "$.body[*].id": {
+            "match": "type"
+          },
+          "$.body[*].reply_id": {
+            "match": "type"
+          },
+          "$.body[*].project_id": {
+            "match": "type"
+          },
+          "$.body[*].confidential": {
+            "match": "type"
+          },
+          "$.body[*].diff_discussion": {
+            "match": "type"
+          },
+          "$.body[*].expanded": {
+            "match": "type"
+          },
+          "$.body[*].for_commit": {
+            "match": "type"
+          },
+          "$.body[*].individual_note": {
+            "match": "type"
+          },
+          "$.body[*].resolvable": {
+            "match": "type"
+          },
+          "$.body[*].resolved_by_push": {
+            "match": "type"
+          },
+          "$.body[*].notes": {
+            "min": 1
+          },
+          "$.body[*].notes[*].*": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].id": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].author.id": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].author.username": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].author.name": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].author.state": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].author.avatar_url": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].author.show_status": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].author.path": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].created_at": {
+            "match": "regex",
+            "regex": "^\\d{4}-[01]\\d-[0-3]\\dT[0-2]\\d:[0-5]\\d:[0-5]\\d\\.\\d+([+-][0-2]\\d(:?[0-5]\\d)?|Z)$"
+          },
+          "$.body[*].notes[*].updated_at": {
+            "match": "regex",
+            "regex": "^\\d{4}-[01]\\d-[0-3]\\dT[0-2]\\d:[0-5]\\d:[0-5]\\d\\.\\d+([+-][0-2]\\d(:?[0-5]\\d)?|Z)$"
+          },
+          "$.body[*].notes[*].system": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].noteable_id": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].noteable_type": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].resolvable": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].resolved": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].confidential": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].noteable_iid": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].note": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].note_html": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].current_user.can_edit": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].current_user.can_award_emoji": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].current_user.can_resolve": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].current_user.can_resolve_discussion": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].is_noteable_author": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].discussion_id": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].emoji_awardable": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].report_abuse_path": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].noteable_note_url": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].cached_markdown_version": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].human_access": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].is_contributor": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].project_name": {
+            "match": "type"
+          },
+          "$.body[*].notes[*].path": {
+            "match": "type"
+          },
+          "$.body[*].resolved": {
+            "match": "type"
+          }
+        }
+      }
+    }
+  ],
+  "metadata": {
+    "pactSpecification": {
+      "version": "2.0.0"
+    }
+  }
+}
\ No newline at end of file

qa/contracts/contracts/merge_request_page-merge_request_metadata_endpoint.json

+{
+  "consumer": {
+    "name": "Merge Request Page"
+  },
+  "provider": {
+    "name": "Merge Request Metadata Endpoint"
+  },
+  "interactions": [
+    {
+      "description": "a request for Metadata",
+      "request": {
+        "method": "GET",
+        "path": "/diffs_metadata.json",
+        "headers": {
+          "Accept": "*/*"
+        }
+      },
+      "response": {
+        "status": 200,
+        "headers": {
+          "Content-Type": "application/json; charset=utf-8"
+        },
+        "body": {
+          "real_size": "1",
+          "size": 1,
+          "branch_name": "testing-branch-1",
+          "source_branch_exists": true,
+          "target_branch_name": "master",
+          "merge_request_diff": {
+            "created_at": "2022-02-17T11:47:08.804Z",
+            "commits_count": 1,
+            "latest": true,
+            "short_commit_sha": "aee1ffec",
+            "base_version_path": "/gitlab-qa-bot/contract-testing/-/merge_requests/1/diffs?diff_id=10581773",
+            "head_version_path": "/gitlab-qa-bot/contract-testing/-/merge_requests/1/diffs?diff_head=true",
+            "version_path": "/gitlab-qa-bot/contract-testing/-/merge_requests/1/diffs?diff_id=10581773",
+            "compare_path": "/gitlab-qa-bot/contract-testing/-/merge_requests/1/diffs?diff_id=10581773&start_sha=aee1ffec2299c0cfb17c8821e931339b73a3759f"
+          },
+          "latest_diff": true,
+          "latest_version_path": "/gitlab-qa-bot/contract-testing/-/merge_requests/1/diffs",
+          "added_lines": 1,
+          "removed_lines": 1,
+          "render_overflow_warning": false,
+          "email_patch_path": "/gitlab-qa-bot/contract-testing/-/merge_requests/1.patch",
+          "plain_diff_path": "/gitlab-qa-bot/contract-testing/-/merge_requests/1.diff",
+          "merge_request_diffs": [
+            {
+              "commits_count": 1,
+              "latest": true,
+              "short_commit_sha": "aee1ffec",
+              "base_version_path": "/gitlab-qa-bot/contract-testing/-/merge_requests/1/diffs?diff_id=10581773",
+              "head_version_path": "/gitlab-qa-bot/contract-testing/-/merge_requests/1/diffs?diff_head=true",
+              "version_path": "/gitlab-qa-bot/contract-testing/-/merge_requests/1/diffs?diff_id=10581773",
+              "compare_path": "/gitlab-qa-bot/contract-testing/-/merge_requests/1/diffs?diff_id=10581773&start_sha=aee1ffec2299c0cfb17c8821e931339b73a3759f"
+            }
+          ],
+          "definition_path_prefix": "/gitlab-qa-bot/contract-testing/-/blob/aee1ffec2299c0cfb17c8821e931339b73a3759f",
+          "diff_files": [
+            {
+              "added_lines": 1,
+              "removed_lines": 1,
+              "new_path": "Gemfile",
+              "old_path": "Gemfile",
+              "new_file": false,
+              "deleted_file": false,
+              "submodule": false,
+              "file_identifier_hash": "67d82b8716a5b6c52c7abf0b2cd99c7594ed3587",
+              "file_hash": "de3150c01c3a946a6168173c4116741379fe3579"
+            }
+          ],
+          "has_conflicts": false,
+          "can_merge": false,
+          "project_path": "gitlab-qa-bot/contract-testing",
+          "project_name": "contract-testing"
+        },
+        "matchingRules": {
+          "$.body.real_size": {
+            "match": "type"
+          },
+          "$.body.size": {
+            "match": "type"
+          },
+          "$.body.branch_name": {
+            "match": "type"
+          },
+          "$.body.source_branch_exists": {
+            "match": "type"
+          },
+          "$.body.target_branch_name": {
+            "match": "type"
+          },
+          "$.body.merge_request_diff.created_at": {
+            "match": "regex",
+            "regex": "^\\d{4}-[01]\\d-[0-3]\\dT[0-2]\\d:[0-5]\\d:[0-5]\\d\\.\\d+([+-][0-2]\\d(:?[0-5]\\d)?|Z)$"
+          },
+          "$.body.merge_request_diff.commits_count": {
+            "match": "type"
+          },
+          "$.body.merge_request_diff.latest": {
+            "match": "type"
+          },
+          "$.body.merge_request_diff.short_commit_sha": {
+            "match": "type"
+          },
+          "$.body.merge_request_diff.base_version_path": {
+            "match": "type"
+          },
+          "$.body.merge_request_diff.head_version_path": {
+            "match": "type"
+          },
+          "$.body.merge_request_diff.version_path": {
+            "match": "type"
+          },
+          "$.body.merge_request_diff.compare_path": {
+            "match": "type"
+          },
+          "$.body.latest_diff": {
+            "match": "type"
+          },
+          "$.body.latest_version_path": {
+            "match": "type"
+          },
+          "$.body.added_lines": {
+            "match": "type"
+          },
+          "$.body.removed_lines": {
+            "match": "type"
+          },
+          "$.body.render_overflow_warning": {
+            "match": "type"
+          },
+          "$.body.email_patch_path": {
+            "match": "type"
+          },
+          "$.body.plain_diff_path": {
+            "match": "type"
+          },
+          "$.body.merge_request_diffs": {
+            "min": 1
+          },
+          "$.body.merge_request_diffs[*].*": {
+            "match": "type"
+          },
+          "$.body.merge_request_diffs[*].commits_count": {
+            "match": "type"
+          },
+          "$.body.merge_request_diffs[*].latest": {
+            "match": "type"
+          },
+          "$.body.merge_request_diffs[*].short_commit_sha": {
+            "match": "type"
+          },
+          "$.body.merge_request_diffs[*].base_version_path": {
+            "match": "type"
+          },
+          "$.body.merge_request_diffs[*].head_version_path": {
+            "match": "type"
+          },
+          "$.body.merge_request_diffs[*].version_path": {
+            "match": "type"
+          },
+          "$.body.merge_request_diffs[*].compare_path": {
+            "match": "type"
+          },
+          "$.body.definition_path_prefix": {
+            "match": "type"
+          },
+          "$.body.diff_files": {
+            "min": 1
+          },
+          "$.body.diff_files[*].*": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].added_lines": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].removed_lines": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].new_path": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].old_path": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].new_file": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].deleted_file": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].submodule": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].file_identifier_hash": {
+            "match": "type"
+          },
+          "$.body.diff_files[*].file_hash": {
+            "match": "type"
+          },
+          "$.body.has_conflicts": {
+            "match": "type"
+          },
+          "$.body.can_merge": {
+            "match": "type"
+          },
+          "$.body.project_path": {
+            "match": "type"
+          },
+          "$.body.project_name": {
+            "match": "type"
+          }
+        }
+      }
+    }
+  ],
+  "metadata": {
+    "pactSpecification": {
+      "version": "2.0.0"
+    }
+  }
+}
\ No newline at end of file

qa/contracts/provider/Rakefile

+# frozen_string_literal: true
+
+require 'pact/tasks/verification_task'
+
+Pact::VerificationTask.new(:metadata) do |pact|
+  pact.uri '../contracts/merge_request_page-merge_request_metadata_endpoint.json', pact_helper: './spec/metadata_helper.rb'
+end
+
+Pact::VerificationTask.new(:discussions) do |pact|
+  pact.uri '../contracts/merge_request_page-merge_request_discussions_endpoint.json', pact_helper: './spec/discussions_helper.rb'
+end
+
+Pact::VerificationTask.new(:diffs) do |pact|
+  pact.uri '../contracts/merge_request_page-merge_request_diffs_endpoint.json', pact_helper: './spec/diffs_helper.rb'
+end
+
+task 'test:merge_request' => ['pact:verify:metadata', 'pact:verify:discussions', 'pact:verify:diffs']

qa/contracts/provider/environments/base.rb

+# frozen_string_literal: true
+
+require 'faraday'
+
+module Environments
+  class Base
+    attr_writer :base_url, :merge_request
+
+    def call(env)
+      @payload
+    end
+
+    def http(endpoint)
+      Faraday.default_adapter = :net_http
+      response = Faraday.get(@base_url + endpoint)
+      @payload = [response.status, response.headers, [response.body]]
+      self
+    end
+
+    def merge_request(endpoint)
+      if endpoint.include? '.json'
+        http(@merge_request + endpoint)
+      end
+    end
+  end
+end

qa/contracts/provider/environments/local.rb

+# frozen_string_literal: true
+
+require_relative './base'
+
+module Environments
+  class Local < Base
+    def initialize
+      @base_url = ENV['CONTRACT_HOST']
+      @merge_request = ENV['CONTRACT_MR']
+    end
+  end
+end

qa/contracts/provider/spec/diffs_helper.rb

+# frozen_string_literal: true
+
+require_relative '../environments/local'
+
+module DiffsHelper
+  local = Environments::Local.new
+
+  Pact.service_provider "Merge Request Diffs Endpoint" do
+    app { local.merge_request('/diffs_batch.json?page=0') }
+
+    honours_pact_with 'Merge Request Page' do
+      pact_uri '../contracts/merge_request_page-merge_request_diffs_endpoint.json'
+    end
+  end
+end

qa/contracts/provider/spec/discussions_helper.rb

+# frozen_string_literal: true
+
+require_relative '../environments/local'
+
+module DiscussionsHelper
+  local = Environments::Local.new
+
+  Pact.service_provider "Merge Request Discussions Endpoint" do
+    app { local.merge_request('/discussions.json') }
+
+    honours_pact_with 'Merge Request Page' do
+      pact_uri '../contracts/merge_request_page-merge_request_discussions_endpoint.json'
+    end
+  end
+end

qa/contracts/provider/spec/metadata_helper.rb

+# frozen_string_literal: true
+
+require_relative '../environments/local'
+
+module MetadataHelper
+  local = Environments::Local.new
+
+  Pact.service_provider "Merge Request Metadata Endpoint" do
+    app { local.merge_request('/diffs_metadata.json') }
+
+    honours_pact_with 'Merge Request Page' do
+      pact_uri '../contracts/merge_request_page-merge_request_metadata_endpoint.json'
+    end
+  end
+end