TypeScript 3.1

一些浏览器厂商特定的类型从lib.d.ts中被移除

TypeScript内置的.d.ts库(lib.d.ts等)现在会部分地从DOM规范的Web IDL文件中生成。因此有一些浏览器厂商特定的类型被移除了。

点击这里查看被移除类型的完整列表：

CanvasRenderingContext2D.mozImageSmoothingEnabled CanvasRenderingContext2D.msFillRule CanvasRenderingContext2D.oImageSmoothingEnabled CanvasRenderingContext2D.webkitImageSmoothingEnabled Document.caretRangeFromPoint Document.createExpression Document.createNSResolver Document.execCommandShowHelp Document.exitFullscreen Document.exitPointerLock Document.focus Document.fullscreenElement Document.fullscreenEnabled Document.getSelection Document.msCapsLockWarningOff Document.msCSSOMElementFloatMetrics Document.msElementsFromRect Document.msElementsFromPoint Document.onvisibilitychange Document.onwebkitfullscreenchange Document.onwebkitfullscreenerror Document.pointerLockElement Document.queryCommandIndeterm Document.URLUnencoded Document.webkitCurrentFullScreenElement Document.webkitFullscreenElement Document.webkitFullscreenEnabled Document.webkitIsFullScreen Document.xmlEncoding Document.xmlStandalone Document.xmlVersion DocumentType.entities DocumentType.internalSubset DocumentType.notations DOML2DeprecatedSizeProperty Element.msContentZoomFactor Element.msGetUntransformedBounds Element.msMatchesSelector Element.msRegionOverflow Element.msReleasePointerCapture Element.msSetPointerCapture Element.msZoomTo Element.onwebkitfullscreenchange Element.onwebkitfullscreenerror Element.webkitRequestFullScreen Element.webkitRequestFullscreen ElementCSSInlineStyle ExtendableEventInit ExtendableMessageEventInit FetchEventInit GenerateAssertionCallback HTMLAnchorElement.Methods HTMLAnchorElement.mimeType HTMLAnchorElement.nameProp HTMLAnchorElement.protocolLong HTMLAnchorElement.urn HTMLAreasCollection HTMLHeadElement.profile HTMLImageElement.msGetAsCastingSource HTMLImageElement.msGetAsCastingSource HTMLImageElement.msKeySystem HTMLImageElement.msPlayToDisabled HTMLImageElement.msPlayToDisabled HTMLImageElement.msPlayToPreferredSourceUri HTMLImageElement.msPlayToPreferredSourceUri HTMLImageElement.msPlayToPrimary HTMLImageElement.msPlayToPrimary HTMLImageElement.msPlayToSource HTMLImageElement.msPlayToSource HTMLImageElement.x HTMLImageElement.y HTMLInputElement.webkitdirectory HTMLLinkElement.import HTMLMetaElement.charset HTMLMetaElement.url HTMLSourceElement.msKeySystem HTMLStyleElement.disabled HTMLSummaryElement MediaQueryListListener MSAccountInfo MSAudioLocalClientEvent MSAudioLocalClientEvent MSAudioRecvPayload MSAudioRecvSignal MSAudioSendPayload MSAudioSendSignal MSConnectivity MSCredentialFilter MSCredentialParameters MSCredentials MSCredentialSpec MSDCCEvent MSDCCEventInit MSDelay MSDescription MSDSHEvent MSDSHEventInit MSFIDOCredentialParameters MSIceAddrType MSIceType MSIceWarningFlags MSInboundPayload MSIPAddressInfo MSJitter MSLocalClientEvent MSLocalClientEventBase MSNetwork MSNetworkConnectivityInfo MSNetworkInterfaceType MSOutboundNetwork MSOutboundPayload MSPacketLoss MSPayloadBase MSPortRange MSRelayAddress MSSignatureParameters MSStatsType MSStreamReader MSTransportDiagnosticsStats MSUtilization MSVideoPayload MSVideoRecvPayload MSVideoResolutionDistribution MSVideoSendPayload NotificationEventInit PushEventInit PushSubscriptionChangeInit RTCIdentityAssertionResult RTCIdentityProvider RTCIdentityProviderDetails RTCIdentityValidationResult Screen.deviceXDPI Screen.logicalXDPI SVGElement.xmlbase SVGGraphicsElement.farthestViewportElement SVGGraphicsElement.getTransformToElement SVGGraphicsElement.nearestViewportElement SVGStylable SVGTests.hasExtension SVGTests.requiredFeatures SyncEventInit ValidateAssertionCallback WebKitDirectoryEntry WebKitDirectoryReader WebKitEntriesCallback WebKitEntry WebKitErrorCallback WebKitFileCallback WebKitFileEntry WebKitFileSystem Window.clearImmediate Window.msSetImmediate* Window.setImmediate

推荐：

如果你的运行时能够保证这些名称是可用的（比如一个仅针对IE的应用），那么可以在本地添加那些声明，例如：

对于Element.msMatchesSelector，在本地的dom.ie.d.ts文件里添加如下代码：

  1. interface Element {
  2.     msMatchesSelector(selectors: string): boolean;
  3. }

相似地，若要添加clearImmediate和setImmediate，你可以在本地的dom.ie.d.ts里添加Window声明：

  1. interface Window {
  2.     clearImmediate(handle: number): void;
  3.     setImmediate(handler: (...args: any[]) => void): number;
  4.     setImmediate(handler: any, ...args: any[]): number;
  5. }

细化的函数现在会使用{}，Object和未约束的泛型参数的交叉类型

下面的代码如今会提示x不能被调用：

  1. function foo<T>(x: T | (() => string)) {
  2.     if (typeof x === "function") {
  3.         x();
  4. //      ~~~
  5. // Cannot invoke an expression whose type lacks a call signature. Type '(() => string) | (T & Function)' has no compatible call signatures.
  6.     }
  7. }

这是因为，不同于以前的T会被细化掉，如今T会被扩展成T & Function。然而，因为这个类型没有声明调用签名，类型系统无法找到通用的调用签名可以适用于T & Function和() => string。

因此，考虑使用一个更确切的类型，而不是{}或Object，并且考虑给T添加额外的约束条件。