TypeScript 1.8

类型参数作为约束

¥Type parameters as constraints

使用 TypeScript 1.8，类型参数约束可以引用来自同一类型参数列表的类型参数。以前，这是一个错误。此功能通常称为 F 有界多态性。

¥With TypeScript 1.8 it becomes possible for a type parameter constraint to reference type parameters from the same type parameter list. Previously this was an error. This capability is usually referred to as F-Bounded Polymorphism.

示例

¥Example

ts
function assign<T extends U, U>(target: T, source: U): T {
  for (let id in source) {
    target[id] = source[id];
  }
  return target;
}
let x = { a: 1, b: 2, c: 3, d: 4 };
assign(x, { b: 10, d: 20 });
assign(x, { e: 0 }); // Error

控制流分析错误

¥Control flow analysis errors

TypeScript 1.8 引入了控制流分析，以帮助捕获用户容易遇到的常见错误。继续阅读以了解更多详细信息，并查看以下错误的实际示例：

¥TypeScript 1.8 introduces control flow analysis to help catch common errors that users tend to run into. Read on to get more details, and check out these errors in action:

无法访问的代码

¥Unreachable code

保证在运行时不会执行的语句现在会被正确标记为无法访问的代码错误。例如，在无条件 return、throw、break 或 continue 语句之后的语句被视为无法访问。使用 allowUnreachableCode 禁用不可达代码检测和报告。

¥Statements guaranteed to not be executed at run time are now correctly flagged as unreachable code errors. For instance, statements following unconditional return, throw, break or continue statements are considered unreachable. Use allowUnreachableCode to disable unreachable code detection and reporting.

示例

¥Example

以下是一个简单的代码无法访问错误示例：

¥Here’s a simple example of an unreachable code error:

ts
function f(x) {
  if (x) {
    return true;
  } else {
    return false;
  }
  x = 0; // Error: Unreachable code detected.
}

此功能捕获的一个更常见的错误是在 return 语句后添加换行符：

¥A more common error that this feature catches is adding a newline after a return statement:

ts
function f() {
  return; // Automatic Semicolon Insertion triggered at newline
  {
    x: "string"; // Error: Unreachable code detected.
  }
}

由于 JavaScript 会自动在行尾终止 return 语句，因此对象字面量变成了一个块。

¥Since JavaScript automatically terminates the return statement at the end of the line, the object literal becomes a block.

未使用的标签

¥Unused labels

未使用的标签也会被标记。与无法访问的代码检查一样，这些检查默认处于启用状态；使用 allowUnusedLabels 停止报告这些错误。

¥Unused labels are also flagged. Just like unreachable code checks, these are turned on by default; use allowUnusedLabels to stop reporting these errors.

示例

¥Example

ts
loop: while (x > 0) {
  // Error: Unused label.
  x++;
}

隐式返回

¥Implicit returns

在 JS 中，代码路径不返回值的函数会隐式返回 undefined。这些现在可以被编译器标记为隐式返回。默认情况下，此检查处于关闭状态；使用 noImplicitReturns 启用它。

¥Functions with code paths that do not return a value in JS implicitly return undefined. These can now be flagged by the compiler as implicit returns. The check is turned off by default; use noImplicitReturns to turn it on.

示例

¥Example

ts
function f(x) {
  // Error: Not all code paths return a value.
  if (x) {
    return false;
  }
  // implicitly returns `undefined`
}

Case 子句的 fall-through 问题

¥Case clause fall-throughs

TypeScript 可以报告 switch 语句中 case 子句非空的 fall-through 情况的错误。此检查默认关闭，可以使用 noFallthroughCasesInSwitch 启用。

¥TypeScript can reports errors for fall-through cases in switch statement where the case clause is non-empty. This check is turned off by default, and can be enabled using noFallthroughCasesInSwitch.

示例

¥Example

使用 noFallthroughCasesInSwitch 时，此示例将触发错误：

¥With noFallthroughCasesInSwitch, this example will trigger an error:

ts
switch (x % 2) {
  case 0: // Error: Fallthrough case in switch.
    console.log("even");
  case 1:
    console.log("odd");
    break;
}

但是，在下面的例子中，由于 fall-through case 为空，因此不会报告任何错误：

¥However, in the following example, no error will be reported because the fall-through case is empty:

ts
switch (x % 3) {
  case 0:
  case 1:
    console.log("Acceptable");
    break;
  case 2:
    console.log("This is *two much*!");
    break;
}

React 中的函数组件

¥Function Components in React

TypeScript 现在支持 函数组件。这些是轻量级组件，可以轻松组合其他组件：

¥TypeScript now supports Function components. These are lightweight components that easily compose other components:

ts
// Use parameter destructuring and defaults for easy definition of 'props' type
const Greeter = ({ name = "world" }) => <div>Hello, {name}!</div>;
// Properties get validated
let example = <Greeter name="TypeScript 1.8" />;

对于此功能和简化的 props，请务必使用 react.d.ts 的最新版本。

¥For this feature and simplified props, be sure to use the latest version of react.d.ts.

React 中简化的 props 类型管理

¥Simplified props type management in React

在包含最新版本 react.d.ts（见上文）的 TypeScript 1.8 中，我们还大大简化了 props 类型的声明。

¥In TypeScript 1.8 with the latest version of react.d.ts (see above), we’ve also greatly simplified the declaration of props types.

具体来说：

¥Specifically:

• 你不再需要显式声明 ref 和 key 或 extend React.Props

  ¥You no longer need to either explicitly declare ref and key or extend React.Props

• ref 和 key 属性将以正确的类型出现在所有组件上

  ¥The ref and key properties will appear with correct types on all components

• 在无状态函数组件的实例中，ref 属性被正确禁用。

  ¥The ref property is correctly disallowed on instances of Stateless Function components

从模块扩展全局/模块作用域

¥Augmenting global/module scope from modules

用户现在可以声明他们想要对现有模块进行的任何扩展，或者其他使用者已经对现有模块进行的任何扩展。模块扩展看起来像普通的旧式环境模块声明（即 declare module "foo" { } 语法），并且直接嵌套在你自己的模块中，或者嵌套在另一个顶层环境外部模块中。

¥Users can now declare any augmentations that they want to make, or that any other consumers already have made, to an existing module. Module augmentations look like plain old ambient module declarations (i.e. the declare module "foo" { } syntax), and are directly nested either your own modules, or in another top level ambient external module.

此外，TypeScript 还具有 declare global { } 形式的全局扩充的概念。这使得模块可以在必要时扩充全局类型，例如 Array。

¥Furthermore, TypeScript also has the notion of global augmentations of the form declare global { }. This allows modules to augment global types such as Array if necessary.

模块扩展的名称解析使用与 import 和 export 声明中的模块说明符相同的规则。模块扩充中的声明会与任何现有声明合并，就像它们在同一文件中声明一样。

¥The name of a module augmentation is resolved using the same set of rules as module specifiers in import and export declarations. The declarations in a module augmentation are merged with any existing declarations the same way they would if they were declared in the same file.

模块扩充和全局扩充都无法将新项添加到顶层作用域。 - 它们只能 “patch” 现有的声明。

¥Neither module augmentations nor global augmentations can add new items to the top level scope - they can only “patch” existing declarations.

示例

¥Example

在这里，map.ts 可以声明它将在内部修补 observable.ts 中的 Observable 类型，并为其添加 map 方法。

¥Here map.ts can declare that it will internally patch the Observable type from observable.ts and add the map method to it.

ts
// observable.ts
export class Observable<T> {
  // ...
}

ts
// map.ts
import { Observable } from "./observable";
// Create an augmentation for "./observable"
declare module "./observable" {
    // Augment the 'Observable' class definition with interface merging
    interface Observable<T> {
        map<U>(proj: (el: T) => U): Observable<U>;
    }
}
Observable.prototype.map = /*...*/;

ts
// consumer.ts
import { Observable } from "./observable";
import "./map";
let o: Observable<number>;
o.map((x) => x.toFixed());

同样，可以使用 declare global 声明从模块中扩展全局范围：

¥Similarly, the global scope can be augmented from modules using a declare global declarations:

示例

¥Example

ts
// Ensure this is treated as a module.
export {};
declare global {
  interface Array<T> {
    mapToNumbers(): number[];
  }
}
Array.prototype.mapToNumbers = function () {
  /* ... */
};

字符串字面量类型

¥String literal types

API 期望某些值具有一组特定的字符串的情况并不少见。例如，考虑一个 UI 库，它可以在控制 “easing” 动画的 “easing”。 的同时在屏幕上移动元素。

¥It’s not uncommon for an API to expect a specific set of strings for certain values. For instance, consider a UI library that can move elements across the screen while controlling the “easing” of the animation.

ts
declare class UIElement {
  animate(options: AnimationOptions): void;
}
interface AnimationOptions {
  deltaX: number;
  deltaY: number;
  easing: string; // Can be "ease-in", "ease-out", "ease-in-out"
}

但是，这很容易出错。 - 没有什么可以阻止用户意外拼错有效的缓动值之一：

¥However, this is error prone - there is nothing stopping a user from accidentally misspelling one of the valid easing values:

ts
// No errors
new UIElement().animate({ deltaX: 100, deltaY: 100, easing: "ease-inout" });

在 TypeScript 1.8 中，我们引入了字符串字面量类型。这些类型的书写方式与字符串字面量相同，但位于不同的类型位置。

¥With TypeScript 1.8, we’ve introduced string literal types. These types are written the same way string literals are, but in type positions.

用户现在可以确保类型系统能够捕获此类错误。这是我们使用字符串字面量类型的新 AnimationOptions：

¥Users can now ensure that the type system will catch such errors. Here’s our new AnimationOptions using string literal types:

ts
interface AnimationOptions {
  deltaX: number;
  deltaY: number;
  easing: "ease-in" | "ease-out" | "ease-in-out";
}
// Error: Type '"ease-inout"' is not assignable to type '"ease-in" | "ease-out" | "ease-in-out"'
new UIElement().animate({ deltaX: 100, deltaY: 100, easing: "ease-inout" });

改进了并集/交叉类型推断

¥Improved union/intersection type inference

TypeScript 1.8 改进了涉及源端和目标端（均为并集或交叉类型）的类型推断。例如，当从 string | string[] 推断到 string | T 时，我们将类型简化为 string[] 和 T，从而推断出 T 的 string[]。

¥TypeScript 1.8 improves type inference involving source and target sides that are both union or intersection types. For example, when inferring from string | string[] to string | T, we reduce the types to string[] and T, thus inferring string[] for T.

示例

¥Example

ts
type Maybe<T> = T | void;
function isDefined<T>(x: Maybe<T>): x is T {
  return x !== undefined && x !== null;
}
function isUndefined<T>(x: Maybe<T>): x is void {
  return x === undefined || x === null;
}
function getOrElse<T>(x: Maybe<T>, defaultValue: T): T {
  return isDefined(x) ? x : defaultValue;
}
function test1(x: Maybe<string>) {
  let x1 = getOrElse(x, "Undefined"); // string
  let x2 = isDefined(x) ? x : "Undefined"; // string
  let x3 = isUndefined(x) ? "Undefined" : x; // string
}
function test2(x: Maybe<number>) {
  let x1 = getOrElse(x, -1); // number
  let x2 = isDefined(x) ? x : -1; // number
  let x3 = isUndefined(x) ? -1 : x; // number
}

使用以下代码连接 AMD 和 System 模块 --outFile

¥Concatenate AMD and System modules with --outFile

将 outFile 与 --module amd 或 --module system 结合指定会将编译中的所有模块连接到包含多个模块闭包的单个输出文件中。

¥Specifying outFile in conjunction with --module amd or --module system will concatenate all modules in the compilation into a single output file containing multiple module closures.

每个模块的名称将根据其相对于 rootDir 的位置进行计算。

¥A module name will be computed for each module based on its relative location to rootDir.

示例

¥Example

ts
// file src/a.ts
import * as B from "./lib/b";
export function createA() {
  return B.createB();
}

ts
// file src/lib/b.ts
export function createB() {
  return {};
}

结果：

¥Results in:

js
define("lib/b", ["require", "exports"], function (require, exports) {
  "use strict";
  function createB() {
    return {};
  }
  exports.createB = createB;
});
define("a", ["require", "exports", "lib/b"], function (require, exports, B) {
  "use strict";
  function createA() {
    return B.createB();
  }
  exports.createA = createA;
});

支持 default 与 SystemJS 的互操作导入

¥Support for default import interop with SystemJS

像 SystemJS 这样的模块加载器会封装 CommonJS 模块，并将其作为 default ES6 导入暴露出来。这使得在 SystemJS 和 CommonJS 模块实现之间无法共享定义文件，因为模块的形状会根据加载器的不同而有所不同。

¥Module loaders like SystemJS wrap CommonJS modules and expose them as a default ES6 import. This makes it impossible to share the definition files between the SystemJS and CommonJS implementation of the module as the module shape looks different based on the loader.

设置新的编译器标志 allowSyntheticDefaultImports 表示模块加载器执行某种合成的默认导入成员创建操作，而这些操作未在导入的 .ts 或 .d.ts 中指明。编译器将推断出存在一个具有整个模块本身形状的 default 导出。

¥Setting the new compiler flag allowSyntheticDefaultImports indicates that the module loader performs some kind of synthetic default import member creation not indicated in the imported .ts or .d.ts. The compiler will infer the existence of a default export that has the shape of the entire module itself.

系统模块默认启用此标志。

¥System modules have this flag on by default.

允许在循环中捕获 let/const

¥Allow captured let/const in loops

之前是一个错误，现在 TypeScript 1.8 已支持。现在，循环内和函数中捕获的 let/const 声明都会被触发，以正确匹配 let/const 的新鲜度语义。

¥Previously an error, now supported in TypeScript 1.8. let/const declarations within loops and captured in functions are now emitted to correctly match let/const freshness semantics.

示例

¥Example

ts
let list = [];
for (let i = 0; i < 5; i++) {
  list.push(() => i);
}
list.forEach((f) => console.log(f()));

编译为：

¥is compiled to:

js
var list = [];
var _loop_1 = function (i) {
  list.push(function () {
    return i;
  });
};
for (var i = 0; i < 5; i++) {
  _loop_1(i);
}
list.forEach(function (f) {
  return console.log(f());
});

结果为：

¥And results in

cmd
0
1
2
3
4

改进了对 for..in 语句的检查

¥Improved checking for for..in statements

之前 for..in 变量的类型会推断为 any；允许编译器忽略 for..in 函数体内的无效引用。

¥Previously the type of a for..in variable is inferred to any; that allowed the compiler to ignore invalid uses within the for..in body.

从 TypeScript 1.8 开始：

¥Starting with TypeScript 1.8:

• for..in 语句中声明的变量类型隐式为 string。

  ¥The type of a variable declared in a for..in statement is implicitly string.

• 当一个具有 T 类型数字索引签名的对象（例如数组）被一个包含 for..in 语句的 for..in 变量索引时，对于一个具有数字索引签名但不具有字符串索引签名的对象（同样例如数组），生成的值的类型为 T。

  ¥When an object with a numeric index signature of type T (such as an array) is indexed by a for..in variable of a containing for..in statement for an object with a numeric index signature and without a string index signature (again such as an array), the value produced is of type T.

示例

¥Example

ts
var a: MyObject[];
for (var x in a) {
  // Type of x is implicitly string
  var obj = a[x]; // Type of obj is MyObject
}

模块现在已触发带有 "use strict"; 序言

¥Modules are now emitted with a "use strict"; prologue

模块始终按照 ES6 以严格模式解析，但对于非 ES6 目标，生成的代码中不会遵循此模式。从 TypeScript 1.8 开始，触发的模块始终处于严格模式。由于 TS 将大多数严格模式错误视为编译时错误，因此这应该不会对大多数代码造成任何可见的变化，但这意味着 TS 代码中一些过去在运行时默默失败的操作（例如赋值给 NaN）现在会大声失败。你可以参考严格模式下的 MDN 文章，了解严格模式和非严格模式之间差异的详细列表。

¥Modules were always parsed in strict mode as per ES6, but for non-ES6 targets this was not respected in the generated code. Starting with TypeScript 1.8, emitted modules are always in strict mode. This shouldn’t have any visible changes in most code as TS considers most strict mode errors as errors at compile time, but it means that some things which used to silently fail at runtime in your TS code, like assigning to NaN, will now loudly fail. You can reference the MDN Article on strict mode for a detailed list of the differences between strict mode and non-strict mode.

在 --allowJs 中包含 .js 文件

¥Including .js files with --allowJs

项目中通常有一些外部源文件可能不是用 TypeScript 编写的。或者，你可能正在将 JS 代码库转换为 TS，但仍希望将所有 JS 代码与新 TS 代码的输出打包到一个文件中。

¥Often there are external source files in your project that may not be authored in TypeScript. Alternatively, you might be in the middle of converting a JS code base into TS, but still want to bundle all your JS code into a single file with the output of your new TS code.

.js 文件现在允许作为 tsc 的输入。TypeScript 编译器会检查输入的 .js 文件是否存在语法错误，并根据 target 和 module 标志触发有效的输出。输出也可以与其他 .ts 文件合并。与 .ts 文件一样，仍会为 .js 文件生成源映射。

¥.js files are now allowed as input to tsc. The TypeScript compiler checks the input .js files for syntax errors, and emits valid output based on the target and module flags. The output can be combined with other .ts files as well. Source maps are still generated for .js files just like with .ts files.

使用 --reactNamespace 的自定义 JSX 工厂

¥Custom JSX factories using --reactNamespace

将 --reactNamespace <JSX factory Name> 和 --jsx react 一起传递，可以使用与默认 React 不同的 JSX 工厂。

¥Passing --reactNamespace <JSX factory Name> along with --jsx react allows for using a different JSX factory from the default React.

新的工厂名称将用于调用 createElement 和 __spread 函数。

¥The new factory name will be used to call createElement and __spread functions.

示例

¥Example

ts
import { jsxFactory } from "jsxFactory";
var div = <div>Hello JSX!</div>;

编译环境：

¥Compiled with:

shell
tsc --jsx react --reactNamespace jsxFactory --m commonJS

结果：

¥Results in:

js
"use strict";
var jsxFactory_1 = require("jsxFactory");
var div = jsxFactory_1.jsxFactory.createElement("div", null, "Hello JSX!");

this 型防护

¥this-based type guards

TypeScript 1.8 将 用户定义的类型保护函数 扩展为类和接口方法。

¥TypeScript 1.8 extends user-defined type guard functions to class and interface methods.

this is T 现在是类和接口中方法的有效返回类型注解。当用于类型缩小的位置（例如 if 语句）时，调用表达式目标对象的类型将被缩小为 T。

¥this is T is now valid return type annotation for methods in classes and interfaces. When used in a type narrowing position (e.g. if statement), the type of the call expression target object would be narrowed to T.

示例

¥Example

ts
class FileSystemObject {
  isFile(): this is File {
    return this instanceof File;
  }
  isDirectory(): this is Directory {
    return this instanceof Directory;
  }
  isNetworked(): this is Networked & this {
    return this.networked;
  }
  constructor(public path: string, private networked: boolean) {}
}
class File extends FileSystemObject {
  constructor(path: string, public content: string) {
    super(path, false);
  }
}
class Directory extends FileSystemObject {
  children: FileSystemObject[];
}
interface Networked {
  host: string;
}
let fso: FileSystemObject = new File("foo/bar.txt", "foo");
if (fso.isFile()) {
  fso.content; // fso is File
} else if (fso.isDirectory()) {
  fso.children; // fso is Directory
} else if (fso.isNetworked()) {
  fso.host; // fso is networked
}

官方 TypeScript NuGet 包

¥Official TypeScript NuGet package

从 TypeScript 1.8 开始，官方 NuGet 软件包可用于 TypeScript 编译器 (tsc.exe) 以及 MSBuild 集成（Microsoft.TypeScript.targets 和 Microsoft.TypeScript.Tasks.dll）。

¥Starting with TypeScript 1.8, official NuGet packages are available for the TypeScript Compiler (tsc.exe) as well as the MSBuild integration (Microsoft.TypeScript.targets and Microsoft.TypeScript.Tasks.dll).

稳定的软件包可在此处获取：

¥Stable packages are available here:

• Microsoft.TypeScript.Compiler

• Microsoft.TypeScript.MSBuild

此外，myget 上提供了一个与 每日 npm 包 匹配的夜间 NuGet 包：

¥Also, a nightly NuGet package to match the nightly npm package is available on myget:

• TypeScript 预览版

  ¥TypeScript-Preview

来自 tsc 的更美观的错误消息

¥Prettier error messages from tsc

我们理解，大量的单色输出可能会对眼睛造成一定程度的不适。颜色可以帮助辨别消息的开始和结束位置，当错误输出过多时，这些视觉线索非常重要。

¥We understand that a ton of monochrome output can be a little difficult on the eyes. Colors can help discern where a message starts and ends, and these visual clues are important when error output gets overwhelming.

只需传递 pretty 命令行选项，TypeScript 就能提供更丰富的输出，并提供有关出错位置的上下文。

¥By just passing the pretty command line option, TypeScript gives a more colorful output with context about where things are going wrong.

VS 2015 中 JSX 代码的着色

¥Colorization of JSX code in VS 2015

在 TypeScript 1.8 中，JSX 标签现在可以在 Visual Studio 2015 中分类并显示颜色。

¥With TypeScript 1.8, JSX tags are now classified and colorized in Visual Studio 2015.

可以通过更改 Tools->Options->Environment->Fonts and Colors 页面中 VB XML 颜色和字体设置的字体和颜色设置来进一步自定义分类。

¥The classification can be further customized by changing the font and color settings for the VB XML color and font settings through Tools->Options->Environment->Fonts and Colors page.

--project (-p) 标志现在可以采用任何文件路径

¥The --project (-p) flag can now take any file path

--project 命令行选项最初只能接受包含 tsconfig.json 的文件夹的路径。考虑到构建配置的不同场景，允许 --project 指向任何其他兼容的 JSON 文件是合理的。例如，用户可能希望在 Node 5 中使用 CommonJS 模块来支持 ES2015，而在浏览器上使用 AMD 模块来支持 ES5。通过这项新功能，用户可以轻松地仅使用 tsc 管理两个单独的构建目标，而无需执行诸如将 tsconfig.json 文件放在不同目录中之类的棘手解决方法。

¥The --project command line option originally could only take paths to a folder containing a tsconfig.json. Given the different scenarios for build configurations, it made sense to allow --project to point to any other compatible JSON file. For instance, a user might want to target ES2015 with CommonJS modules for Node 5, but ES5 with AMD modules for the browser. With this new work, users can easily manage two separate build targets using tsc alone without having to perform hacky workarounds like placing tsconfig.json files in separate directories.

如果指定目录，旧行为仍然保持不变。 - 编译器将尝试在名为 tsconfig.json 的目录中查找文件。

¥The old behavior still remains the same if given a directory - the compiler will try to find a file in the directory named tsconfig.json.

允许在 tsconfig.json 中添加注释

¥Allow comments in tsconfig.json

能够记录你的配置总是好的！tsconfig.json 现在接受单行和多行注释。

¥It’s always nice to be able to document your configuration! tsconfig.json now accepts single and multi-line comments.

{
  "compilerOptions": {
    "target": "ES2015", // running on node v5, yaay!
    "sourceMap": true // makes debugging easier
  },
  /*
   * Excluded files
   */
  "exclude": ["file.d.ts"]
}

支持输出到 IPC 驱动文件

¥Support output to IPC-driven files

TypeScript 1.8 允许用户将 outFile 参数与特殊文件系统实体（如命名管道、设备等）一起使用。

¥TypeScript 1.8 allows users to use the outFile argument with special file system entities like named pipes, devices, etc.

例如，在许多类 Unix 系统上，文件 /dev/stdout 可以访问标准输出流。

¥As an example, on many Unix-like systems, the standard output stream is accessible by the file /dev/stdout.

shell
tsc foo.ts --outFile /dev/stdout

它还可以用于在命令之间进行管道输出。

¥This can be used to pipe output between commands as well.

例如，我们可以将生成的 JavaScript 代码通过管道传输到像 pretty-js 这样的漂亮打印机中：

¥As an example, we can pipe our emitted JavaScript into a pretty printer like pretty-js:

shell
tsc foo.ts --outFile /dev/stdout | pretty-js

改进了 Visual Studio 2015 中对 tsconfig.json 的支持

¥Improved support for tsconfig.json in Visual Studio 2015

TypeScript 1.8 允许所有项目类型中使用 tsconfig.json 文件。这包括 ASP.NET v4 项目、控制台应用以及使用 TypeScript 项目类型的 HTML 应用。此外，你不再局限于单个 tsconfig.json 文件，而是可以添加多个，每个文件都将作为项目的一部分进行构建。这允许你分离应用不同部分的配置，而无需使用多个不同的项目。

¥TypeScript 1.8 allows tsconfig.json files in all project types. This includes ASP.NET v4 projects, Console Application, and the Html Application with TypeScript project types. Further, you are no longer limited to a single tsconfig.json file but can add multiple, and each will be built as part of the project. This allows you to separate the configuration for different parts of your application without having to use multiple different projects.

当你添加 tsconfig.json 文件时，我们还会禁用项目属性页面。这意味着所有配置更改都必须在 tsconfig.json 文件本身中进行。

¥We also disable the project properties page when you add a tsconfig.json file. This means that all configuration changes have to be made in the tsconfig.json file itself.

一些限制

¥A couple of limitations

• 如果你添加 tsconfig.json 文件，则不属于该上下文的 TypeScript 文件将不会被编译。

  ¥If you add a tsconfig.json file, TypeScript files that are not considered part of that context are not compiled.

• Apache Cordova 应用仍然受到单个 tsconfig.json 文件的限制，该文件必须位于根目录或 scripts 文件夹中。

  ¥Apache Cordova Apps still have the existing limitation of a single tsconfig.json file, which must be in either the root or the scripts folder.

• 大多数项目类型中没有 tsconfig.json 的模板。

  ¥There is no template for tsconfig.json in most project types.