fc

.editorconfig

@@ -0,0 +1,12 @@
+# http://editorconfig.org
+root = true
+
+[*]
+indent_style = space
+indent_size = 2
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[*.md]
+trim_trailing_whitespace = false

.gitignore

@@ -0,0 +1,8 @@
+coverage/
+node_modules/
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+.nyc_output
+lib
+lib_test

.npmignore

@@ -0,0 +1,16 @@
+# gitignore
+
+coverage/
+node_modules/
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+.nyc_output
+lib
+lib_test
+
+# npmignore
+
+src/
+__tests__/
+.vscode/

.travis.yml

@@ -0,0 +1,7 @@
+language: node_js
+node_js:
+  - 'node' # use latest stable nodejs version
+script:
+  - npm run coverage # jest test with coverage flag does coverage too
+after_script:
+  - 'cat coverage/lcov.info | ./node_modules/.bin/coveralls' # sends the coverage report to coveralls

.vscode/launch.json

@@ -0,0 +1,32 @@
+{
+  // Use IntelliSense to learn about possible Node.js debug attributes.
+  // Hover to view descriptions of existing attributes.
+  // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+  "version": "0.2.0",
+  "configurations": [
+    {
+      "type": "node",
+      "request": "launch",
+      "name": "Debug file",
+      "program": "${workspaceRoot}/lib/${fileBasenameNoExtension}.js",
+      "cwd": "${workspaceRoot}",
+      "sourceMaps": true,
+      "smartStep": true,
+      "preLaunchTask": "build",
+      "outFiles": [
+        "${workspaceRoot}/lib/*.js"
+      ]
+    },
+    {
+      "type": "node",
+      "request": "launch",
+      "name": "Debug test",
+      "program": "${workspaceRoot}/node_modules/jest/bin/jest.js",
+      "args": [
+        "--findRelatedTests",
+        "${relativeFile}"
+      ],
+      "cwd": "${workspaceRoot}"
+    }
+  ]
+}

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+    "typescript.tsdk": "node_modules/typescript/lib/"
+}

.vscode/tasks.json

@@ -0,0 +1,59 @@
+{
+  // See https://go.microsoft.com/fwlink/?LinkId=733558
+  // for the documentation about the tasks.json format
+  "version": "2.0.0",
+  "tasks": [
+    {
+      "taskName": "Run current file",
+      "command": "ts-node ${relativeFile}",
+      "type": "shell",
+      "problemMatcher": []
+    },
+    {
+      "type": "npm",
+      "label": "clean",
+      "script": "clean",
+      "problemMatcher": []
+    },
+    {
+      "type": "npm",
+      "label": "build",
+      "script": "build",
+      "group": {
+        "kind": "build",
+        "isDefault": true
+      },
+      "problemMatcher":[]
+    },
+    {
+      "type": "npm",
+      "label": "format",
+      "script": "format",
+      "problemMatcher": []
+    },
+    {
+      "type": "npm",
+      "label": "coverage",
+      "script": "coverage",
+      "problemMatcher": []
+    },
+    {
+      "type": "npm",
+      "label": "test",
+      "script": "test",
+      "group": {
+        "kind": "test",
+        "isDefault": true
+      },
+      "problemMatcher": []
+    },
+    {
+      "type": "npm",
+      "label": "lint",
+      "script": "lint",
+      "problemMatcher": [
+        "$eslint-stylish"
+      ]
+    }
+  ]
+}

LICENSE

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2018
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

README.md

@@ -0,0 +1,39 @@
+[![Build Status](https://travis-ci.org/kuyoonjo/ctry.svg?branch=master)](https://travis-ci.org/kuyoonjo/ctry.svg?branch=master)
+[![Coverage Status](https://coveralls.io/repos/github/kuyoonjo/ctry/badge.svg?branch=master)](https://coveralls.io/github/kuyoonjo/ctry?branch=master)
+[![MIT license](http://img.shields.io/badge/license-MIT-brightgreen.svg)](http://opensource.org/licenses/MIT)
+
+# Intro
+
+`ctry` tries to resolve a promise with `timeout` and `chance` configurations.
+
+```ts
+/**
+ * ctry
+ * @param ctryFunc a function returns a promise
+ * @param timeout timeout in ms
+ * @param tries number of changes
+ */
+function ctry<T>(
+  ctryFunc: CtryFunction<T>,
+  timeout: number = 5000,
+  tries: number = 1,
+): Promise<T>;
+```
+
+> Q: When shoul you use it?
+> A: Trying to do sth. with timeout, and/or give it more than one chance.
+
+eg. Trying validate a web server whether it is reachable. The codes use `HEAD` method to do a request, and try 3 times.
+
+```ts
+import axios from 'axios';
+import { ctry } from 'ctry';
+
+(async () => {
+  try {
+    await ctry(() => axios.head('https://example.com'), 5000, 3);
+  } catch (e) {
+    console.error(e);
+  }
+})();
+```

__tests__/ctry-spec.ts

@@ -0,0 +1,55 @@
+import { ctry, ERR_TIMEOUT } from '../src/ctry';
+
+test('Should resolve', async () => {
+  const fn = () => Promise.resolve(1);
+  const res = await ctry(_ => fn());
+  expect(res).toBe(1);
+});
+
+test('Should reject', async () => {
+  const fn = () => Promise.reject(1);
+  try {
+    await ctry(_ => fn(), 1000, 1);
+  } catch (e) {
+    expect(e).toBe(1);
+  }
+});
+
+test('Should reject with timeout', async () => {
+  const fn = () =>
+    new Promise(resolve => {
+      setTimeout(() => {
+        resolve(1);
+      }, 1000);
+    });
+  try {
+    await ctry(_ => fn(), 100, 1);
+  } catch (e) {
+    expect(e.message).toBe(ERR_TIMEOUT);
+  }
+});
+
+test('Should resolve with 3 tries', async () => {
+  const p = new Promise(resolve => {
+    setTimeout(() => {
+      resolve(1);
+    }, 1000);
+  });
+  const fn = () => p;
+  const res = await ctry(_ => fn(), 400, 3);
+  expect(res).toBe(1);
+});
+
+test('Should reject with 2 tries', async () => {
+  const p = new Promise(resolve => {
+    setTimeout(() => {
+      resolve(1);
+    }, 1000);
+  });
+  const fn = () => p;
+  try {
+    await ctry(_ => fn(), 400, 2);
+  } catch (e) {
+    expect(e.message).toBe(ERR_TIMEOUT);
+  }
+});

__tests__/index-spec.ts

@@ -0,0 +1,6 @@
+import * as index from '../src/index';
+
+test('Should export', () => {
+  expect(index.ctry).toBeTruthy();
+  expect(index.ERR_TIMEOUT).toBeTruthy();
+});

package.json

@@ -0,0 +1,55 @@
+{
+  "name": "ctry",
+  "version": "1.0.0",
+  "description": "ctry tries to resolve a promise with timeout and chance configurations.",
+  "license": "MIT",
+  "repository": "https://github.com/kuyoonjo/ctry.git",
+  "author": {
+    "name": "Yu Chen",
+    "email": "yu@chen.news",
+    "url": "https://yu.chen.news"
+  },
+  "keywords": [""],
+  "files": ["lib"],
+  "main": "lib/index.js",
+  "typings": "lib/index.d.ts",
+  "scripts": {
+    "clean": "rimraf lib && rimraf coverage",
+    "format":
+      "prettier --write \"{src,__tests__}/**/*.ts\" --single-quote --trailing-comma es5",
+    "lint": "tslint --force --format verbose \"src/**/*.ts\"",
+    "prepublishOnly": "npm run build",
+    "prebuild":
+      "npm run clean && npm run format && npm run lint && echo Using TypeScript && tsc --version",
+    "build": "tsc --pretty",
+    "test": "jest",
+    "coverage": "jest --coverage",
+    "watch": "npm run build -- --watch",
+    "watch:test": "jest --watch"
+  },
+  "dependencies": {},
+  "devDependencies": {
+    "@types/jest": "^23.3.3",
+    "@types/node": "^10.11.4",
+    "coveralls": "^3.0.2",
+    "jest": "^23.6.0",
+    "prettier": "^1.14.3",
+    "rimraf": "^2.6.2",
+    "ts-jest": "^23.10.3",
+    "ts-node": "^7.0.1",
+    "tslint": "^5.11.0",
+    "tslint-config-prettier": "^1.15.0",
+    "typescript": "^3.1.1"
+  },
+  "engines": {
+    "node": ">=6.0.0"
+  },
+  "jest": {
+    "transform": {
+      ".(ts)": "<rootDir>/node_modules/ts-jest/preprocessor.js"
+    },
+    "testRegex": "(/__tests__/.*|\\.(test|spec))\\.(ts|js)$",
+    "moduleFileExtensions": ["ts", "js"],
+    "testEnvironment": "node"
+  }
+}

src/ctry.ts

@@ -0,0 +1,44 @@
+/*
+ * @Author: Yu Chen
+ * @Date: 2018-11-12 17:44:56
+ * @Last Modified by: Yu Chen
+ * @Last Modified time: 2018-11-12 21:17:40
+ */
+
+export const ERR_TIMEOUT = 'ERR_TIMEOUT';
+
+/**
+ * ctry
+ * @param ctryFunc a function returns a promise
+ * @param timeout timeout in ms
+ * @param tries number of changes
+ */
+export function ctry<T>(
+  ctryFunc: CtryFunction<T>,
+  timeout: number = 5000,
+  tries: number = 1
+): Promise<T> {
+  const tf = () =>
+    new Promise<never>((_, reject) => {
+      const id = setTimeout(() => {
+        clearTimeout(id);
+        reject(new Error(ERR_TIMEOUT));
+      }, timeout);
+    });
+
+  const tryit = async (t = 1): Promise<T> => {
+    try {
+      const res = await Promise.race([ctryFunc(t), tf()]);
+      return res;
+    } catch (e) {
+      if (ERR_TIMEOUT === e.message && t < tries) {
+        return tryit(t + 1);
+      } else {
+        throw e;
+      }
+    }
+  };
+  return tryit();
+}
+
+export type CtryFunction<T> = (challenge: number) => Promise<T>;

src/index.ts

@@ -0,0 +1 @@
+export * from './ctry';