TypeScript泛型参数默认类型和新的strict编译选项

class Greeting extends react.Component {
  render() {
    return <span>Hello, {this.props.name}!</span>;
  }
}

declare namespace React {
  class Component {
    props: any;
    state: any;
  }
}

class Greeting extends React.Component {
  render() {
    return <span>Hello, {this.props.name}!</span>
  }
}

<Greeting name="world" />

<span>Hello, World!</span>

declare namespace React {
  class Component <Props, State> {
    props: Props;
    state: State;
  }
}

type GreetingProps = { name: string };

class Greeting extends React.Component<GreetingProps, any> {
  render() {
    return <span>Hello, {this.props.name}!</span>;
  }
}

// Error: 泛型类型 Component<Props, State>
// 需要 2 个类型参数。
class Greeting extends React.Component {
  render() {
    return <span>Hello, {this.props.name}!</span>;
  }
}

class Greeting extends React.Component<any, any> {
  render() {
    return <span>Hello, {this.props.name}!</span>;
  }
}

declare namespace React {
  class Component<Props = any, State = any> {
    props: Props;
    state: State;
  }
}

class Greeting extends React.Component {
  render() {
    return <span>Hello, {this.props.name}!</span>;
  }
}

type GreetingProps = { name: string };

class Greeting extends React.Component<GreetingProps, any> {
  render() {
    return <span>Hello, {this.props.name}!</span>;
  }
}

class Greeting extends React.Component<GreetingProps> {
  render() {
    return <span>Hello, {this.props.name}!</span>;
  }
}

type constructor<T> = new (...args: any[]) => T;
type constructable = Constructor<{}>;

type Constructor<T = {}> = new (...args: any[]) => T;

{
  "strict": true,
  "alwaysStrict": false
}

{
  "pilerOptions": {
    / Basic Options /
    "target": "es5",                          / Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', or 'ESNEXT'. /
    "module": "monjs",                     / Specify module code generation: 'monjs', 'amd', 'system', 'umd' or 'es2015'. /
    // "lib": [],                             / Specify library files to be included in the pilation:  /
    // "allowJs": true,                       / Allow JavaScript files to be piled. /
    // "checkJs": true,                       / Report errors in .js files. /
    // "jsx": "preserve",                     / Specify JSX code generation: 'preserve', 'react-native', or 'react'. /
    // "declaration": true,                   / Generates corresponding '.d.ts' file. /
    // "sourceMap": true,                     / Generates corresponding '.map' file. /
    // "outFile": "./",                       / Concatenate and emit output to single file. /
    // "outDir": "./",                        / Redirect output structure to the directory. /
    // "rootDir": "./",                       / Specify the root directory of input files. Use to control the output directory structure with --outDir. /
    // "removeComments": true,                / Do not emit ments to output. /
    // "noEmit": true,                        / Do not emit outputs. /
    // "importHelpers": true,                 / Import emit helpers from 'tslib'. /
    // "downlevelIteration": true,            / Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. /
    // "isolatedModules": true,               / Transpile each file as a separate module (similar to 'ts.transpileModule'). /

    / Strict Type-Checking Options /
    "strict": true                            / Enable all strict type-checking options. /
    // "noImplicitAny": true,                 / Raise error on expressions and declarations with an implied 'any' type. /
    // "strictNullChecks": true,              / Enable strict null checks. /
    // "noImplicitThis": true,                / Raise error on 'this' expressions with an implied 'any' type. /
    // "alwaysStrict": true,                  / Parse in strict mode and emit "use strict" for each source file. /

    / Additional Checks /
    // "noUnusedLocals": true,                / Report errors on unused locals. /
    // "noUnusedParameters": true,            / Report errors on unused parameters. /
    // "noImplicitReturns": true,             / Report error when not all code paths in function return a value. /
    // "noFallthroughCasesInSwitch": true,    / Report errors for fallthrough cases in switch statement. /

    / Module Resolution Options /
    // "moduleResolution": "node",            / Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). /
    // "baseUrl": "./",                       / Base directory to resolve non-absolute module names. /
    // "paths": {},                           / A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. /
    // "rootDirs": [],                        / List of root folders whose bined content represents the structure of the project at runtime. /
    // "typeRoots": [],                       / List of folders to include type definitions from. /
    // "types": [],                           / Type declaration files to be included in pilation. /
    // "allowSyntheticDefaultImports": true,  / Allow default imports from modules with no default export. This does not affect code emit, just typechecking. /

    / Source Map Options /
    // "sourceRoot": "./",                    / Specify the location where debugger should locate TypeScript files instead of source locations. /
    // "mapRoot": "./",                       / Specify the location where debugger should locate map files instead of generated locations. /
    // "inlineSourceMap": true,               / Emit a single file with source maps instead of having a separate file. /
    // "inlineSources": true,                 / Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set. /

    / Experimental Options /
    // "experimentalDecorators": true,        / Enables experimental support for ES7 decorators. /
    // "emitDecoratorMetadata": true,         / Enables experimental support for emitting type metadata for decorators. /
  }
}