foreword
ESLint is a tool for identifying and reporting pattern matching in ECMAScript/JavaScript code, and its goal is to ensure code consistency and avoid errors. In many respects, it is similar to JSLint and JSHint, with a few exceptions:
- ESLint uses Espree to parse JavaScript.
- ESLint uses AST to analyze patterns in code ESLint is fully pluggable.
- Each rule is a plugin and you can add more rules at runtime.
After using ESLint in the project, some rules will make people scratch their heads, but sometimes we feel that a certain rule is completely meaningless, so we want to disable some rules that are meaningless or you think are ridiculous. It sounds a bit self-defeating, but ESLint actually allows us to customize the rules.
configuration syntax
Add custom rules to the rules configuration item:
// 配置参数
rules: {
"规则名1": [规则值, 规则配置],
"规则名2": [规则值, 规则配置]
}
Rule value (determines whether to enable/disable):
"off"或者0 //关闭规则
"warn"或者1 //在打开的规则作为警告（不影响退出代码）
"error"或者2 //把规则作为一个错误（退出代码触发时为1）
Rule name (each rule corresponds to a rule name, just like the space indentation rule mentioned in the preface corresponds to indent):
always or never
- “never” (default) disallows space between the function name and the opening parenthesis.
- “always” requires space between the function name and the opening parenthesis.
Further, in “always” mode, a second object option is available that contains a single boolean allowNewlines property.
never
1、Examples of incorrect code for this rule with the default “never” option:
/*eslint func-call-spacing: ["error", "never"]*/
fn ();
fn
();
2、Examples of correct code for this rule with the default “never” option:
/*eslint func-call-spacing: ["error", "never"]*/
fn();
always
1、Examples of incorrect code for this rule with the “always” option:
/*eslint func-call-spacing: ["error", "always"]*/
fn();
fn
();
2、Examples of correct code for this rule with the “always” option:
/*eslint func-call-spacing: ["error", "always"]*/
fn ();