自制一个自动导入( auto import )的vscode插件

遇到的问题

使用vue时，每次导入组件都十分的麻烦，得先写明组件标签，然后在script标签中import导入,在components中显式声明。。。遇到这种劳动重复性问题时，我都会想是否能用脚本完成？有幸使用了vscode，可以自定义打造我们的自动导入插件

开始

使用yo code初始化项目。百度上关于初始化项目一大堆，不重点说了。。

自动提示组件名称

第一步就是要先能自动提示组件名称，vscode中关于显示建议的核心API是（ 看API直接ctrl+左键点击const vscode = require('vscode') 即可，d.ts描述文件比官网API文档都详细 ）

export function registerCompletionItemProvider(selector: DocumentSelector, provider: CompletionItemProvider, ...triggerCharacters: string[]): Disposable;

其中: CompletionItemProvider包含provideCompletionItems和resolveCompletionItem.

provideCompletionItems返回选项集合（暂时这么叫吧）,resolveCompletionItem具体处理你选择选项时的事件

根目录下新建autotip.js文件, 具体用法见注释

const vscode = require('vscode');
const fs = require('fs');

module.exports = function (context) {
  let rangeline = 0
  let rangeCol = 0

  /**
   * 只支持单文件夹！
   * @param {*} document 
   * @param {*} position 
   */
  function provideCompletionItems(document, position) {
    let arr = [];
    // 递归寻找组件名
    let readFile = (fileDir, filter) => {
      let filearr = fs.readdirSync(fileDir)
      filearr.forEach((v) => {
        if (fs.statSync(fileDir + '/' + v).isDirectory()) {
          readFile(fileDir + '/' + v, filter)
        } else {
          if (v.indexOf(filter) !== -1 && v.substring(v.lastIndexOf('.') + 1) === 'vue') {
            arr.push(v.substring(0, v.lastIndexOf('.')))
          }
        }
      })
    }

    // 找到光标所在的一行
    const line = document.lineAt(position);
    const lineText = line.text.substring(0, position.character);

    rangeline = position.line
    rangeCol = position.character

    let workspaceFolders = vscode.workspace.workspaceFolders.map(item => item.uri.path);
    // 找到根目录
    let rootpath = workspaceFolders[0];
    // 递归寻找src目录下的vue文件
    readFile(rootpath.substring(1) + '/src', lineText.substring(lineText.indexOf('<') + 1));
    // 返回所有vue文件
    return arr.map((v) => {
      return new vscode.CompletionItem(v, vscode.CompletionItemKind.Field);
    })
  }


  function resolveCompletionItem(item) {
    // 把vue文件名处理成xxx-xxx的形式
    let content = item.label[0].toLowerCase() + item.label.substring(1)
    content = content.replace(/[A-Z]/g, (text) => {
      return `-${text.toLowerCase()}`
    })
    item.insertText = content
    return item;
  }

  context.subscriptions.push(vscode.languages.registerCompletionItemProvider('vue', {
    provideCompletionItems,
    resolveCompletionItem
  }, '<')); // 触发建议的按键
};

完成后，在extension.js中引入

// The module 'vscode' contains the VS Code extensibility API
// Import the module and reference it with the alias vscode in your code below
const vscode = require('vscode');
const autotip = require('./autptip')

// this method is called when your extension is activated
// your extension is activated the very first time the command is executed
function activate(context) {

    // Use the console to output diagnostic information (console.log) and errors (console.error)
    // This line of code will only be executed once when your extension is activated
    console.log('Congratulations, your extension "autotip" is now active!');
    // The command has been defined in the package.json file
    // Now provide the implementation of the command with  registerCommand
    // The commandId parameter must match the command field in package.json

    // 引入
    autotip(context)
}
exports.activate = activate;

// this method is called when your extension is deactivated
function deactivate() {
}
exports.deactivate = deactivate;

在package.json中注册

 "activationEvents": [
        "onLanguage:vue"
 ],

现在你可以按F5测试，是否生成了建议列表

接受建议时触发动作

按下tab或者enter时触发以下动作：

1. 在script标签中写入 import xxx from 'xxxx'模板
2. 在components对象中写入引用

万变不离其中，都是用nodejs的IO文件流完成工作

找到script标签所在位置

先写几个通用方法

// 找到过滤文件
let readFile = (fileDir, filter) => {
      let filearr = fs.readdirSync(fileDir)
      filearr.forEach((v) => {
        if (fs.statSync(fileDir + '/' + v).isDirectory()) {
          readFile(fileDir + '/' + v, filter)
        } else {
          let reg = new RegExp(filter, 'i'); // 忽略大小写
          if (reg.test(v) && v.substring(v.lastIndexOf('.') + 1) === 'vue' && v.length === filter.length + 4) {
            obj.name = v.substring(0, v.lastIndexOf('.'))
            obj.path = fileDir + '/' + v.substring(0, v.lastIndexOf('.'))
          }
        }
      })
    }
// 找到某个字符串在编辑器中的行号
    let getLineNumber = (filter) => {
      let scriptline = -1;
      for (let i = 0; i < document.lineCount; i++) {
        let str = document.lineAt(i).text;
        if (str.trim().indexOf(filter) !== -1) {
          scriptline = i;
          break;
        }
      }
      return scriptline;
    }

找到script标签的位置如下:

    let scriptline = getLineNumber('