docs: init utils md

Author: winchesHe

docs/docs/utils.md

@@ -0,0 +1,116 @@
+## chainFn 函数
+
+### source code
+```ts
+type ExecutorFn = (...args: any) => any;
+
+const flat = (arr: any[], num = 1) => {
+    let i = 0;
+    while (arr.some((item) => Array.isArray(item))) {
+        arr = [].concat(...arr);
+        i++;
+        if (i >= num) break;
+    }
+    return arr;
+};
+
+export class ChainFn {
+    resList: any[];
+    executorList: any[];
+    errorList: any[];
+
+    constructor(executor?: ExecutorFn, args?: any, resList: any[] = [], executorList: any[] = [], errorList: any[] = []) {
+        this.resList = resList;
+        this.executorList = executorList;
+        this.errorList = errorList;
+        args = flat([args]);
+
+        // 添加执行函数
+        executor && this.executorList.push([executor, args]);
+    }
+
+    public add(onResFn: ExecutorFn, args?: any) {
+        args = flat([args]);
+        return new ChainFn(onResFn, args, this.resList, this.executorList, this.errorList);
+    }
+
+    private async executeSync(executor: Function, args: any[]) {
+        return executor instanceof Promise ? await (executor as any).apply(this, args) : executor.apply(this, args);
+    }
+
+    public async run(onResFn?: Function, args?: any): Promise<ChainFn> {
+        await this.getValue();
+        args = flat([args]);
+
+        if (onResFn) {
+            try {
+                const returnValue = await this.executeSync(onResFn, [this.resList, ...args]);
+                returnValue && this.resList.push(returnValue);
+            } catch (error) {
+                this.errorList.push(error);
+            }
+        }
+
+        return new ChainFn(undefined, undefined, this.resList, this.executorList, this.errorList);
+    }
+
+    public clear() {
+        return new ChainFn(undefined, undefined, [], [], []);
+    }
+
+    public async get(allRes = false): Promise<any> {
+        await this.getValue();
+        this.resList  = this.resList.filter(v => v);
+        return allRes ? this.resList : this.resList[this.resList.length-1];
+    }
+
+    private async getValue() {
+        for (let index = 0; index < this.executorList.length; index++) {
+            const [executor, args, isDo = false] = this.executorList[index];
+            const useRes = executor.name === '' ? true : false;
+            
+            if (isDo)
+                continue;
+            try {
+                const value = useRes ? await this.executeSync(executor, [this.resList]) : await this.executeSync(executor, args);
+                this.resList.push(value);
+                this.executorList[index].push(true);
+            } catch (error) {
+                this.errorList.push(error);
+            }
+        }
+    }
+
+    public catch(callBack: Function) {
+        if (this.errorList.length) {
+            return callBack.apply(this, this.errorList);
+        }
+    }
+}
+```
+
+### template
+```ts
+console.log(await new ChainFn()
+    .add(say, ['2', 2])
+    .add(say, '3')
+    .add(say, '4')
+    .add(say, '5')
+    .add(say, '6')
+    .add((res) => {
+        console.log(res, '获取前方的结果');
+        
+        return say('7');
+    })
+    .get(), '最后的结果');
+/**
+ *  2
+ *  3
+ *  4
+ *  5
+ *  6
+ *  [ '2', '3', '4', '5', '6' ] 获取前方的结果
+ *  7
+ *  7 最后的结果
+ */
+```