operator-linebreak
Enforce consistent linebreak style for operators
Some problems reported by this rule are automatically fixable by the --fix command line option
当一个语句太长而不能放在一行中时，一般会在分隔表达式的运算符旁边插入换行符。我想到的第一个样式是将运算符放在行尾，遵循英文标点符号规则。
var fullHeight = borderTop +
innerHeight +
borderBottom;
一些开发者发现，将运算符放在行首会使代码更易读。
var fullHeight = borderTop
+ innerHeight
+ borderBottom;
规则细节
这条规则为运算符执行了一致的换行风格。
选项
这个规则有两个选项，一个字符串选项和一个对象选项：
字符串选项：
"after"要求将换行符放在运算符之后。"before"要求将换行符放在运算符之前。"none"不允许在运算符的两侧有换行符。
对象选项：
"overrides"覆盖指定操作者的全局设置
默认配置是 "after", { "overrides": { "?": "before", ":": "before" } }
after
使用此规则与 "after" 选项的错误示例：
/*eslint operator-linebreak: ["error", "after"]*/
foo = 1
+
2;
foo = 1
+ 2;
foo
= 5;
if (someCondition
|| otherCondition) {
}
answer = everything
? 42
: foo;
class Foo {
a
= 1;
[b]
= 2;
[c
]
= 3;
}
使用此规则与 "after" 选项的正确示例：
/*eslint operator-linebreak: ["error", "after"]*/
foo = 1 + 2;
foo = 1 +
2;
foo =
5;
if (someCondition ||
otherCondition) {
}
answer = everything ?
42 :
foo;
class Foo {
a =
1;
[b] =
2;
[c
] =
3;
d = 4;
}
before
使用此规则与 "before" 选项的错误示例：
/*eslint operator-linebreak: ["error", "before"]*/
foo = 1 +
2;
foo =
5;
if (someCondition ||
otherCondition) {
}
answer = everything ?
42 :
foo;
class Foo {
a =
1;
[b] =
2;
[c
] =
3;
}
使用此规则与 "before" 选项的正确示例：
/*eslint operator-linebreak: ["error", "before"]*/
foo = 1 + 2;
foo = 1
+ 2;
foo
= 5;
if (someCondition
|| otherCondition) {
}
answer = everything
? 42
: foo;
class Foo {
a
= 1;
[b]
= 2;
[c
]
= 3;
d = 4;
}
none
使用此规则与 "none" 选项的错误示例：
/*eslint operator-linebreak: ["error", "none"]*/
foo = 1 +
2;
foo = 1
+ 2;
if (someCondition ||
otherCondition) {
}
if (someCondition
|| otherCondition) {
}
answer = everything
? 42
: foo;
answer = everything ?
42 :
foo;
class Foo {
a =
1;
[b] =
2;
[c
] =
3;
d
= 4;
[e]
= 5;
[f
]
= 6;
}
使用此规则与 "none" 选项的正确示例：
/*eslint operator-linebreak: ["error", "none"]*/
foo = 1 + 2;
foo = 5;
if (someCondition || otherCondition) {
}
answer = everything ? 42 : foo;
class Foo {
a = 1;
[b] = 2;
[c
] = 3;
d = 4;
[e] = 5;
[f
] = 6;
}
overrides
使用此规则与 { "overrides": { "+=": "before" } } 选项的额外错误示例：
/*eslint operator-linebreak: ["error", "after", { "overrides": { "+=": "before" } }]*/
var thing = 'thing';
thing +=
's';
使用此规则与 { "overrides": { "+=": "before" } } 选项的额外正确示例：
/*eslint operator-linebreak: ["error", "after", { "overrides": { "+=": "before" } }]*/
var thing = 'thing';
thing
+= 's';
使用此规则与 { "overrides": { "?": "ignore", ":": "ignore" } } 选项的额外错误示例：
/*eslint operator-linebreak: ["error", "after", { "overrides": { "?": "ignore", ":": "ignore" } }]*/
answer = everything ?
42
: foo;
answer = everything
?
42
:
foo;
使用此规则与默认的 "after", { "overrides": { "?": "before", ":": "before" } } 选项的错误示例：
/*eslint operator-linebreak: ["error", "after", { "overrides": { "?": "before", ":": "before" } }]*/
foo = 1
+
2;
foo = 1
+ 2;
foo
= 5;
if (someCondition
|| otherCondition) {
}
answer = everything ?
42 :
foo;
使用此规则与默认的 "after", { "overrides": { "?": "before", ":": "before" } } 选项的正确示例：
/*eslint operator-linebreak: ["error", "after", { "overrides": { "?": "before", ":": "before" } }]*/
foo = 1 + 2;
foo = 1 +
2;
foo =
5;
if (someCondition ||
otherCondition) {
}
answer = everything
? 42
: foo;
何时不用
如果你的项目不会使用常见的操作者换行方式，请关闭此规则。
Related Rules
Version
This rule was introduced in ESLint v0.19.0.