padding-line-between-statements

Require or disallow padding lines between statements (padding-line-between-statements)

在--fix命令行上的选项可以自动修复一些被这条规则反映的问题。

此规则要求或不允许给定2种语句之间的空行。适当的空白行可帮助开发人员理解代码。

例如，以下配置需要变量声明和return语句之间的空行。

/*eslint padding-line-between-statements: [
    "error",
    { blankLine: "always", prev: "var", next: "return" }
]*/

function foo() {
    var a = 1;

    return a;
}

规则细节

如果没有配置，此规则不做任何事

配置是具有3个属性的对象; blankLine，prev和next。例如，{ blankLine: "always", prev: "var", next: "return" }意思是“变量声明和return语句之间需要一条或多条空行”。您可以提供任意数量的配置。如果语句对匹配多个配置，则将使用最后一个匹配的配置。

{
    "padding-line-between-statements": [
        "error",
        { "blankLine": LINEBREAK_TYPE, "prev": STATEMENT_TYPE, "next": STATEMENT_TYPE },
        { "blankLine": LINEBREAK_TYPE, "prev": STATEMENT_TYPE, "next": STATEMENT_TYPE },
        { "blankLine": LINEBREAK_TYPE, "prev": STATEMENT_TYPE, "next": STATEMENT_TYPE },
        { "blankLine": LINEBREAK_TYPE, "prev": STATEMENT_TYPE, "next": STATEMENT_TYPE },
        ...
    ]
}

LINEBREAK_TYPE 是以下之一。

例子

此配置在所有return语句之前需要空行，如换行前换行符规则。

配置错误代码示例[{ blankLine: "always", prev: "*", next: "return" }]：

/*eslint padding-line-between-statements: [
    "error",
    { blankLine: "always", prev: "*", next: "return" }
]*/

function foo() {
    bar(
    return;
}

正确的[{ blankLine: "always", prev: "*", next: "return" }]配置代码示例：

/*eslint padding-line-between-statements: [
    "error",
    { blankLine: "always", prev: "*", next: "return" }
]*/

function foo() {
    bar(

    return;
}

function foo() {
    return;
}

这种配置在变量声明的每个序列之后需要空行，如newline-after-var规则。

配置错误代码示例[{ blankLine: "always", prev: ["const", "let", "var"], next: "*"}, { blankLine: "any", prev: ["const", "let", "var"], next: ["const", "let", "var"]}]：

/*eslint padding-line-between-statements: [
    "error",
    { blankLine: "always", prev: ["const", "let", "var"], next: "*"},
    { blankLine: "any",    prev: ["const", "let", "var"], next: ["const", "let", "var"]}
]*/

function foo() {
    var a = 0;
    bar(
}

function foo() {
    let a = 0;
    bar(
}

function foo() {
    const a = 0;
    bar(
}

正确的[{ blankLine: "always", prev: ["const", "let", "var"], next: "*"}, { blankLine: "any", prev: ["const", "let", "var"], next: ["const", "let", "var"]}]配置代码示例：

/*eslint padding-line-between-statements: [
    "error",
    { blankLine: "always", prev: ["const", "let", "var"], next: "*"},
    { blankLine: "any",    prev: ["const", "let", "var"], next: ["const", "let", "var"]}
]*/

function foo() {
    var a = 0;
    var b = 0;

    bar(
}

function foo() {
    let a = 0;
    const b = 0;

    bar(
}

function foo() {
    const a = 0;
    const b = 0;

    bar(
}

这种配置在所有的指令序言之后都需要空行，例如lines-around-directive规则。

配置错误代码示例[{ blankLine: "always", prev: "directive", next: "*" }, { blankLine: "any", prev: "directive", next: "directive" }]：

/*eslint padding-line-between-statements: [
    "error",
    { blankLine: "always", prev: "directive", next: "*" },
    { blankLine: "any",    prev: "directive", next: "directive" }
]*/

"use strict";
foo(

正确的[{ blankLine: "always", prev: "directive", next: "*" }, { blankLine: "any", prev: "directive", next: "directive" }]配置代码示例：

/*eslint padding-line-between-statements: [
    "error",
    { blankLine: "always", prev: "directive", next: "*" },
    { blankLine: "any",    prev: "directive", next: "directive" }
]*/

"use strict";
"use asm";

foo(

兼容性

JSCS: requirePaddingNewLineAfterVariableDeclaration

何时不使用它

如果您不想通知有关换行的警告，那么禁用此规则是安全的。

版

此规则在ESLint 4.0.0-beta.0中引入。

资源

规则来源