Read more about it in our [API testing guide](./api-testing).
### Network Replay
Now you can record network traffic into a HAR file and re-use this traffic in your tests.
To record network into HAR file:
```bash
pwsh bin\Debug\netX\playwright.ps1 open --save-har=example.har --save-har-glob="**/api/**" https://example.com
```
Alternatively, you can record HAR programmatically:
```csharp
var context = await browser.NewContextAsync(new ()
{
RecordHarPath = harPath,
RecordHarUrlFilterString = "**/api/**",
});
// ... Perform actions ...
// Close context to ensure HAR is saved to disk.
context.CloseAsync();
```
Use the new methods [`method: Page.routeFromHAR`] or [`method: BrowserContext.routeFromHAR`] to serve matching responses from the [HAR](http://www.softwareishard.com/blog/har-12-spec/) file:
```csharp
await context.RouteFromHARAsync("example.har");
```
Read more in [our documentation](./network#record-and-replay-requests).
### Advanced Routing
You can now use [`method: Route.fallback`] to defer routing to other handlers.
Note that the new methods [`method: Page.routeFromHAR`] and [`method: BrowserContext.routeFromHAR`] also participate in routing and could be deferred to.
### Web-First Assertions Update
* New method [`method: LocatorAssertions.toHaveValues`] that asserts all selected values of `<select multiple>` element.
* Methods [`method: LocatorAssertions.toContainText`] and [`method: LocatorAssertions.toHaveText`] now accept `ignoreCase` option.
### Miscellaneous
* If there's a service worker that's in your way, you can now easily disable it with a new context option `serviceWorkers`:
```csharp
var context = await Browser.NewContextAsync(new()
{
ServiceWorkers = ServiceWorkerPolicy.Block
});
```
* Using `.zip` path for `recordHar` context option automatically zips the resulting HAR:
```csharp
var context = await Browser.NewContextAsync(new() { RecordHarPath = "example.har.zip" });
```
* If you intend to edit HAR by hand, consider using the `"minimal"` HAR recording mode
that only records information that is essential for replaying:
- Role selectors that allow selecting elements by their [ARIA role](https://www.w3.org/TR/wai-aria-1.2/#roles), [ARIA attributes](https://www.w3.org/TR/wai-aria-1.2/#aria-attributes) and [accessible name](https://w3c.github.io/accname/#dfn-accessible-name).
- New role selectors that allow selecting elements by their [ARIA role](https://www.w3.org/TR/wai-aria-1.2/#roles), [ARIA attributes](https://www.w3.org/TR/wai-aria-1.2/#aria-attributes) and [accessible name](https://w3c.github.io/accname/#dfn-accessible-name).
Playwright 1.17 introduces [frame locators](./api/class-framelocator) - a locator to the iframe on the page. Frame locators capture the logic sufficient to retrieve the `iframe` and then locate elements in that iframe. Frame locators are strict by default, will wait for `iframe` to appear and can be used in Web-First assertions.
Frame locators can be created with either [`method: Page.frameLocator`] or [`method: Locator.frameLocator`] method.
```csharp
var locator = page.FrameLocator("#my-frame").Locator("text=Submit");
await locator.ClickAsync();
```
Read more at [our documentation](./api/class-framelocator).
### Trace Viewer Update
Playwright Trace Viewer is now **available online** at https://trace.playwright.dev! Just drag-and-drop your `trace.zip` file to inspect its contents.
> **NOTE**: trace files are not uploaded anywhere; [trace.playwright.dev](https://trace.playwright.dev) is a [progressive web application](https://web.dev/progressive-web-apps/) that processes traces locally.
- Playwright Test traces now include sources by default (these could be turned off with tracing option)
By using [`Page.Mouse.WheelAsync`](https://playwright.dev/dotnet/docs/next/api/class-mouse#mouse-wheel) you are now able to scroll vertically or horizontally.
### 📜 New Headers API
Previously it was not possible to get multiple header values of a response. This is now possible and additional helper functions are available:
Its now possible to emulate the `forced-colors` CSS media feature by passing it in the [context options](https://playwright.dev/dotnet/docs/next/api/class-browser#browser-new-context-option-forced-colors) or calling [Page.EmulateMediaAsync()](https://playwright.dev/dotnet/docs/next/api/class-page#page-emulate-media).
### New APIs
- [Page.RouteAsync()](https://playwright.dev/dotnet/docs/next/api/class-page#page-route) accepts new `times` option to specify how many times this route should be matched.
- [Page.SetCheckedAsync(selector: string, checked: Boolean)](https://playwright.dev/dotnet/docs/next/api/class-page#page-set-checked) and [Locator.SetCheckedAsync(selector: string, checked: Boolean)](https://playwright.dev/dotnet/docs/next/api/class-locator#locator-set-checked) was introduced to set the checked state of a checkbox.
- [Request.SizesAsync()](https://playwright.dev/dotnet/docs/next/api/class-request#request-sizes) Returns resource size information for given http request.
- [Tracing.StartChunkAsync()](https://playwright.dev/dotnet/docs/next/api/class-tracing#tracing-start-chunk) - Start a new trace chunk.
- [Tracing.StopChunkAsync()](https://playwright.dev/dotnet/docs/next/api/class-tracing#tracing-stop-chunk) - Stops a new trace chunk.
### Important ⚠
* ⬆ .NET Core Apps 2.1 are **no longer** supported for our CLI tooling. As of August 31st, 2021, .NET Core 2.1 is no [longer supported](https://devblogs.microsoft.com/dotnet/net-core-2-1-will-reach-end-of-support-on-august-21-2021/) and will not receive any security updates. We've decided to move the CLI forward and require .NET Core 3.1 as a minimum.
The difference between the [Locator](./api/class-locator) and [ElementHandle](./api/class-elementhandle) is that the latter points to a particular element, while [Locator](./api/class-locator) captures the logic of how to retrieve that element.
React and Vue selectors allow selecting elements by its component name and/or property values. The syntax is very similar to [attribute selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Attribute_selectors) and supports all attribute selector operators.
- [`nth`](./selectors#n-th-element-selector) selector engine is equivalent to the `:nth-match` pseudo class, but could be combined with other selector engines.
- [`visible`](./selectors#selecting-visible-elements) selector engine is equivalent to the `:visible` pseudo class, but could be combined with other selector engines.
