[docs] Describe the TypeScript configuration file (#3913)

* Describe TypeScript configuration

* Rephrase a bit

* Fix path

docs/articles/documentation/test-api/typescript-support.md

@@ -40,3 +40,38 @@ When you run a test Testcafe will output if there are any compilation errors.
 > [Custom Properties](./selecting-page-elements/selectors/extending-selectors.md#custom-properties)
 > and [Custom Methods](./selecting-page-elements/selectors/extending-selectors.md#custom-methods)
 > sections to learn how to extend selectors in TypeScript.
+
+## Customize Compiler Options
+
+TestCafe allows you to specify [TypeScript compiler options](https://www.typescriptlang.org/docs/handbook/compiler-options.html) in the `tsconfig.json` file. You can use these options to enable JSX compilation, import code or typings with `paths` aliases, set aliases to React typings, or customize other compiler settings.
+
+```json
+{
+    "jsx": "react",
+    "jsxFactory": "myFactory",
+    "paths": {
+        "jquery": [ "node_modules/jquery/dist/jquery" ]
+    },
+    "alwaysStrict": true
+}
+```
+
+See the available options in the [TypeScript Compiler Options](https://www.typescriptlang.org/docs/handbook/compiler-options.html) topic.
+
+> Important! You cannot override the `module` and `target` options.
+
+Save `tsconfig.json` to the directory from which you run TestCafe (usually the project's root directory), or specify the [tsConfigPath](../using-testcafe/configuration-file.md#tsconfigpath) option in the [configuration file](../using-testcafe/configuration-file.md) to use a different location.
+
+> `tsconfig.json` supports [JSON5 syntax](https://json5.org/). This allows you to use JavaScript identifiers as object keys, single-quoted strings, comments and other JSON5 features.
+
+TestCafe passes the following options to the TypeScript compiler unless you override them in `tsconfig.json`:
+
+Option                    | Value
+------------------------- | ------
+`allowJs`                 | `true`
+`emitDecoratorMetadata`   | `true`
+`experimentalDecorators`  | `true`
+`inlineSourceMap`         | `true`
+`noImplicitAny`           | `false`
+`pretty`                  | `true`
+`suppressOutputPathCheck` | `true`

docs/articles/documentation/using-testcafe/configuration-file.md

@@ -49,6 +49,7 @@ A configuration file can include the following settings:
 * [developmentMode](#developmentmode)
 * [qrCode](#qrcode)
 * [stopOnFirstFail](#stoponfirstfail)
+* [tsConfigPath](#tsconfigpath)
 * [color](#color)
 * [noColor](#nocolor)
 
@@ -745,6 +746,20 @@ Stops a test run if any test fails.
 *CLI*: [--sf, --stop-on-first-fail](command-line-interface.md#--sf---stop-on-first-fail)  
 *API*: [runner.run({ stopOnFirstFail })](programming-interface/runner.md#run)
 
+## tsConfigPath
+
+Specifies the [TypeScript configuration file](../test-api/typescript-support.md#customize-compiler-options) location.
+
+```json
+{
+    "tsConfigPath": "/Users/s.johnson/testcafe/tsconfig.json"
+}
+```
+
+You can specify an absolute or relative path. Relative paths resolve from the current directory (the directory from which you run TestCafe).
+
+If the `tsConfigPath` option is not specified, TestCafe looks for the `tsconfig.json` file in the current directory.
+
 ## color
 
 Enables colors in the command line.

examples/.testcaferc.json

@@ -54,6 +54,7 @@
         "pfx": "path/to/file.pfx",
         "rejectUnauthorized": true
     },
+    "tsConfigPath": "/Users/s.johnson/testcafe/tsconfig.json",
     "developmentMode": true,
     "qrCode": true
 }