Babel自动生成Attribute文档实现详解

babel-plugin-auto-attr-doc  
├─ lib                      
│  └─ index.js              
├─ src                      
│  └─ index.ts              
├─ __tests__                
│  ├─ fixtures              
│  │  └─ example            
│  │     ├─ actual.ts       
│  │     └─ expected.ts     
│  └─ index.js              
├─ package-lock.json        
├─ package.json             
├─ README.md                
└─ tsconfig.json            

/**
  * @cDescribe 类型
  * @cType string
  * @cOptions 
  * @cDefault 
  */
 export type IType = "primary" | "success" | "warning" | "danger" | "info";
 /**
  * @cDescribe 图标组件
  * @cType string
  * @cOptions 
  * @cDefault 
  */
 export type IIcon = string;
 /**
  * @cDescribe 是否为朴素按钮
  * @cType boolean
  * @cOptions 
  * @cDefault false
  */
 export type IPlain = boolean;

| 属性名 | 说明 | 类型 | 可选值	| 默认值 |
| ------ | ---- | ---- | ----- | ----- |
| type | 类型 | string |  |  |
| icon | 图标组件 | string |  |  |
| plain | 是否为朴素按钮 | boolean |  | false |

it(`should ${caseName.split("-").join(" ")}`, () => {
  const actualPath = path.join(fixtureDir, "source-code.ts");
  // 对源码进行加载解析
  transformFileSync(actualPath);
  // 读取我们准备好的md文件
  const actual = fs
    .readFileSync(path.join(fixtureDir, "actual.md"))
    .toString();
  // 读取插件解析生成的md文件
  const expected = fs
    .readFileSync(path.join(fixtureDir, "api-doc.md"))
    .toString();
  // diff
  const diff = diffChars(actual, expected);
  diff.length > 1 && _print(diff);
  expect(diff.length).toBe(1);
});

type Comment =
  | {
      describe: string;
      type: any;
      options?: any;
      default?: any;
    }
  | undefined;

type ApiTable = {
  attributeName: any;
  attributeDescribe: any;
  attributeType: any;
  attributeOptions: any;
  attributeDefault: any;
};

export default declare(
  (api: BabelAPI, options: Record<string, any>, dirname: string) => {
    api.assertVersion(7);
    return {
      name: "auto-attr-doc",
      pre(this: PluginPass, file: BabelFile) {
        this.set("api-doc", []);
      },
      visitor: {
        ExportNamedDeclaration(
          path: NodePath<t.ExportNamedDeclaration>,
          state: PluginPass
        ) {
          const apidoc = state.get("api-doc");
          // 处理 path.node.leadingComments 中未处理的数据后塞到apidoc中
          state.set("api-doc", apidoc);
        },
      },
      post(this: PluginPass, file: BabelFile) {
        const apidoc = this.get("api-doc");
        const output = generateMD(apidoc);
        const root = path.parse(file.opts.filename || "./").dir;
        fs.writeFileSync(path.join(root, "api-doc.md"), output, {
          encoding: "utf-8",
        });
      },
    } as PluginObj<PluginPass>;
  }
);

{
  ExportNamedDeclaration(
    path: NodePath<t.ExportNamedDeclaration>,
    state: PluginPass
  ) {
    const apidoc = state.get("api-doc");
    let _comment: Comment = undefined;
    path.node.leadingComments?.forEach((comment) => {
      if (!Reflect.has(comment, "skip")) {
        const tags = parseComment(comment.value)?.tags;
        _comment = {
          describe:
            tags?.find((v) => v.title === "cDescribe")?.description || "",
          type: tags?.find((v) => v.title === "cType")?.description || "",
          options:
            tags?.find((v) => v.title === "cOptions")?.description || "",
          default:
            tags?.find((v) => v.title === "cDefault")?.description || "",
        };
        Reflect.set(comment, "skip", true);
      }
    });
    apidoc.push({
      attributeName: (path.node.declaration as t.TypeAlias).id.name.substr(1).toLocaleLowerCase(),
      attributeDescribe: _comment!.describe,
      attributeType: _comment!.type,
      attributeOptions: _comment!.options,
      attributeDefault: _comment!.default,
    } as ApiTable);
    state.set("api-doc", apidoc);
  },
}

const parseComment = (comment: string) => {
  if (!comment) {
    return;
  }
  return doctrine.parse(comment, {
    unwrap: true,
  });
};

const generateMD = (apidoc: Array<ApiTable>) => {
  let raw = `| 属性名 | 说明 | 类型 | 可选值	| 默认值 |\n| ------ | ---- | ---- | ----- | ----- |\n`;
  apidoc.forEach((item) => {
    raw += `| ${item.attributeName} | ${item.attributeDescribe} | ${item.attributeType} | ${item.attributeOptions} | ${item.attributeDefault} |\n`;
  });
  return raw;
};