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[英]Angular Assigning ngIf class boolean properties when calling function to check for different data types
[英]Function argument types are not properly check when assigning functions
我在 TypeScript 遇到了一個奇怪的交互:
type Vector2 = { x: number; y: number };
type Vector3 = { x: number; y: number; z: number };
type Takes2 = (vec: Vector2) => void;
type Takes3 = (vec: Vector3) => void;
let f2: Takes2 = (vec) => console.log(vec.x + vec.y);
let f3: Takes3 = (vec) => console.log(vec.x + vec.y + vec.z);
// This makes sence - we call f2 with Vector3, so the "z" prop is going to be ignored
f3 = f2;
f3({ x: 1, y: 2, z: 5 }); // prints 3 (1 + 2)
// This makes no sence - we call f3 with Vector2, so we read undefined when we read vec.z
f2 = f3;
f2({ x: 1, y: 2 }); // prints NaN! (1 + 2 + undefined)
看起來當一個 function 被分配給另一個變量(或者我猜是作為參數傳遞)時,TypeScript 只檢查類型是否“單向兼容”(arguments 中的一個可以分配給另一個),但不會麻煩檢查參數類型兼容的方向是否與 function 分配的方向相匹配。
總是這樣嗎? 還是可以切換的編譯器選項?
TypeScript 版本:4.4.4 tsconfig.json:
{
"compilerOptions": {
"target": "es5",
"downlevelIteration": true,
"lib": ["dom", "dom.iterable", "esnext"],
"allowJs": true,
"skipLibCheck": true,
"esModuleInterop": true,
"allowSyntheticDefaultImports": true,
// "strict": true,
"forceConsistentCasingInFileNames": true,
"noImplicitAny": true,
"noImplicitReturns": true,
"noFallthroughCasesInSwitch": true,
"module": "esnext",
// "module": "commonjs",
"moduleResolution": "node",
"resolveJsonModule": true,
// "isolatedModules": true,
"noEmit": true,
"jsx": "react",
"baseUrl": ".",
"paths": {
"*": ["./src/*"]
}
},
"types": ["forge-viewer"],
"include": ["src"]
}
您正在尋找的標志是strictFunctionTypes 。
我在您的配置中注意到您已注釋掉"strict": true
。 如果你離開嚴格模式(這是推薦的),那么strictFunctionTypes
就會被包含進來,你就會得到一個編譯錯誤。
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