[docs] Add changelog for v1.4.0 (#4097)

CHANGELOG.md

@@ -1,5 +1,97 @@
 # Changelog
 
+## v1.4.0 (2019-8-7)
+
+### Enhancements
+
+#### :gear: Inject Scripts Into Tested Pages ([#1739](https://github.com/DevExpress/testcafe/issues/1739))
+
+TestCafe now allows you to [inject scripts](https://devexpress.github.io/testcafe/documentation/using-testcafe/common-concepts/inject-scripts-into-tested-pages.html) into pages visited during the tests. Use this feature to add helper functions, mock browser API or import modules.
+
+To add client scripts to all tests, specify them in the command line, API or configuration file. Use the following options:
+
+* the [--cs (--client-scripts)](https://devexpress.github.io/testcafe/documentation/using-testcafe/command-line-interface.html#--cs-pathpath2---client-scripts-pathpath2) command line argument
+
+    ```sh
+    testcafe chrome test.js --client-scripts=mockDate.js,assets/react-helpers.js
+    ```
+
+* the [runner.clientScripts](https://devexpress.github.io/testcafe/documentation/using-testcafe/programming-interface/runner.html#clientscripts) API method
+
+    ```js
+    runner.clientScripts('mockDate.js', 'scripts/react-helpers.js');
+    ```
+
+* the [clientScripts](https://devexpress.github.io/testcafe/documentation/using-testcafe/configuration-file.html#clientscripts) configuration file property
+
+    ```json
+    {
+        "clientScripts": ["mockDate.js", "scripts/react-helpers.js"]
+    }
+    ```
+
+If you need to add scripts to individual fixtures or tests, use the [fixture.clientScripts](https://devexpress.github.io/testcafe/documentation/test-api/test-code-structure.html#inject-scripts-into-tested-pages) and [test.clientScripts](https://devexpress.github.io/testcafe/documentation/test-api/test-code-structure.html#inject-scripts-into-tested-pages) methods in test code.
+
+```js
+fixture `My fixture`
+    .page `http://example.com`
+    .clientScripts('mockDate.js', 'scripts/react-helpers.js');
+```
+
+```js
+test
+    ('My test', async t => { /* ... */ })
+    .clientScripts('mockDate.js', 'scripts/react-helpers.js');
+```
+
+TestCafe also allows you to [inject scripts into specific pages](https://devexpress.github.io/testcafe/documentation/using-testcafe/common-concepts/inject-scripts-into-tested-pages.html#provide-scripts-for-specific-pages).
+
+```js
+fixture `My fixture`
+    .clientScripts({
+        page: 'https://myapp.com/page/',
+        path: 'scripts/vue-helpers.js'
+    });
+```
+
+This is helpful when you need to override the browser API on particular pages and use the default behavior everywhere else.
+
+You can specify the scripts to inject as follows:
+
+* pass the [path to a JavaScript file](https://devexpress.github.io/testcafe/documentation/using-testcafe/common-concepts/inject-scripts-into-tested-pages.html#inject-a-javascript-file) to inject its content:
+
+    ```js
+    fixture `My fixture`
+        .clientScripts({ path: 'assets/jquery.js' });
+    ```
+
+* use the [module name](https://devexpress.github.io/testcafe/documentation/using-testcafe/common-concepts/inject-scripts-into-tested-pages.html#inject-a-module) to inject a module:
+
+    ```js
+    fixture `My fixture`
+        .clientScripts({ module: 'async' });
+    ```
+
+    TestCafe searches for the module's entry point with Node.js mechanisms and injects its content. Note that the browser must be able to execute this module.
+
+* pass the [code](https://devexpress.github.io/testcafe/documentation/using-testcafe/common-concepts/inject-scripts-into-tested-pages.html#inject-script-code) you need to inject:
+
+    ```js
+    fixture `My fixture`
+        .clientScripts({ content: 'Geolocation.prototype.getCurrentPosition = () => new Positon(0, 0);' });
+    ```
+
+For more information, see [Inject Scripts into Tested Pages](https://devexpress.github.io/testcafe/documentation/using-testcafe/common-concepts/inject-scripts-into-tested-pages.html).
+
+### Bug Fixes
+
+* The browser no longer displays 404 errors after the test submits a form ([#3560](https://github.com/DevExpress/testcafe/issues/3560)
+* TestCafe can now download files when testing in headless mode ([#3127](https://github.com/DevExpress/testcafe/issues/3127))
+* TypeScript no longer throws an error when `fixture` or `fixture.page` uses a tag function ([#4042](https://github.com/DevExpress/testcafe/issues/4042))
+* The `load` event now correctly fires for cached images ([testcafe-hammerhead/#1959](https://github.com/DevExpress/testcafe-hammerhead/issues/1959))
+* TestCafe can now read resources from `asar` archives ([testcafe-hammerhead/#2033](https://github.com/DevExpress/testcafe-hammerhead/issues/2033))
+* Fixed a bug when `testcafe-hammerhead` event listeners were called twice ([testcafe-hammerhead/#2062](https://github.com/DevExpress/testcafe-hammerhead/issues/2062))
+
 ## v1.3.3 (2019-7-17)
 
 ### Bug Fixes