no-duplicate-imports

禁止重复模块导入

每个模块使用单个 import 语句将使代码更清晰，因为你可以在一行中看到从该模块导入的所有内容。

¥Using a single import statement per module will make the code clearer because you can see everything being imported from that module on one line.

在以下示例中，第 1 行的 module 导入在第 3 行重复。这些可以结合起来使导入清单更加简洁。

¥In the following example the module import on line 1 is repeated on line 3. These can be combined to make the list of imports more succinct.

import { merge } from 'module';
import something from 'another-module';
import { find } from 'module';
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规则详情

¥Rule Details

此规则要求来自单个模块的所有可以合并的导入都存在于单个 import 语句中。

¥This rule requires that all imports from a single module that can be merged exist in a single import statement.

此规则的错误代码示例：

¥Example of incorrect code for this rule:

/*eslint no-duplicate-imports: "error"*/

import { merge } from 'module';
import something from 'another-module';
import { find } from 'module';
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此规则的正确代码示例：

¥Example of correct code for this rule:

/*eslint no-duplicate-imports: "error"*/

import { merge, find } from 'module';
import something from 'another-module';
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此规则的正确代码示例：

¥Example of correct code for this rule:

/*eslint no-duplicate-imports: "error"*/

// not mergeable
import { merge } from 'module';
import * as something from 'module';
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选项

¥Options

此规则采用一个可选参数，即具有单个键的对象，includeExports 是 boolean。默认为 false。

¥This rule takes one optional argument, an object with a single key, includeExports which is a boolean. It defaults to false.

如果从导入的模块重新导出，你应该将导入添加到 import 语句中，然后直接导出，而不是使用 export ... from。

¥If re-exporting from an imported module, you should add the imports to the import-statement, and export that directly, not use export ... from.

使用 { "includeExports": true } 选项的此规则的错误代码示例：

¥Example of incorrect code for this rule with the { "includeExports": true } option:

/*eslint no-duplicate-imports: ["error", { "includeExports": true }]*/

import { merge } from 'module';

export { find } from 'module';
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使用 { "includeExports": true } 选项的此规则的正确代码示例：

¥Example of correct code for this rule with the { "includeExports": true } option:

/*eslint no-duplicate-imports: ["error", { "includeExports": true }]*/

import { merge, find } from 'module';

export { find };
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使用 { "includeExports": true } 选项的此规则的正确代码示例：

¥Example of correct code for this rule with the { "includeExports": true } option:

/*eslint no-duplicate-imports: ["error", { "includeExports": true }]*/

import { merge, find } from 'module';

// cannot be merged with the above import
export * as something from 'module';

// cannot be written differently
export * from 'module';
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版本

此规则是在 ESLint v2.5.0 中引入。

资源

• 规则源码
• 测试源码