Suggest using spread syntax instead of .apply(). (prefer-spread)

建议使用扩展语法而非.apply() (prefer-spread)

Before ES2015, one must use Function.prototype.apply() to call variadic functions.

在 ES2015 之前，必须使用 Function.prototype.apply() 调用可变参数函数。

var args = [1, 2, 3, 4];
Math.max.apply(Math, args);

In ES2015, one can use spread syntax to call variadic functions.

在 ES2015 中，可以使用扩展语法调用可变参数函数。

/*eslint-env es6*/

var args = [1, 2, 3, 4];
Math.max(...args);

Rule Details

This rule is aimed to flag usage of Function.prototype.apply() in situations where spread syntax could be used instead.

这个规则的目的是在可以使用扩展语法的情况下标记出使用 Function.prototype.apply() 的情况。

Examples

Examples of incorrect code for this rule:

错误 代码示例：

/*eslint prefer-spread: "error"*/

foo.apply(undefined, args);
foo.apply(null, args);
obj.foo.apply(obj, args);

Examples of correct code for this rule:

正确 代码示例：

/*eslint prefer-spread: "error"*/

// Using spread syntax
foo(...args);
obj.foo(...args);

// The `this` binding is different.
foo.apply(obj, args);
obj.foo.apply(null, args);
obj.foo.apply(otherObj, args);

// The argument list is not variadic.
// Those are warned by the `no-useless-call` rule.
foo.apply(undefined, [1, 2, 3]);
foo.apply(null, [1, 2, 3]);
obj.foo.apply(obj, [1, 2, 3]);

Known limitations:

已知的限制：

This rule analyzes code statically to check whether or not the this argument is changed. So, if the this argument is computed in a dynamic expression, this rule cannot detect a violation.

该规则通过静态分析代码的方式检查this参数是否有改变。因此，如果在动态表达式中有 this 参数，该规则不会检查这种情况。

/*eslint prefer-spread: "error"*/

// This warns.
a[i++].foo.apply(a[i++], args);

// This does not warn.
a[++i].foo.apply(a[i], args);

When Not To Use It

This rule should not be used in ES3/5 environments.

此规则不应在 ES3/5 环境中使用。

In ES2015 (ES6) or later, if you don’t want to be notified about Function.prototype.apply() callings, you can safely disable this rule.

在 ES2015 (ES6) 或以后的版本，如果你不希望收到关于 Function.prototype.apply() 调用的通知，关闭此规则即可。

Version

This rule was introduced in ESLint 1.0.0-rc-1.

该规则在 ESLint 1.0.0-rc-1 中被引入。

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