Type test scripts for TypeScript testing

Abstract

TypeScript applications often use untyped JavaScript libraries. To support static type checking of such applications, the typed APIs of the libraries are expressed as separate declaration files. This raises the challenge of checking that the declaration files are correct with respect to the library implementations. Previous work has shown that mismatches are frequent and cause TypeScript's type checker to misguide the programmers by rejecting correct applications and accepting incorrect ones. This paper shows how feedback-directed random testing, which is an automated testing technique that has mostly been used for testing Java libraries, can be adapted to effectively detect such type mismatches. Given a JavaScript library with a TypeScript declaration file, our tool TStest generates a type test script, which is an application that interacts with the library and tests that it behaves according to the type declarations. Compared to alternative solutions that involve static analysis, this approach finds significantly more mismatches in a large collection of real-world JavaScript libraries with TypeScript declaration files, and with fewer false positives. It also has the advantage that reported mismatches are easily reproducible with concrete executions, which aids diagnosis and debugging. CCS Concepts: • Software and its engineering → Software testing and debugging;

Generation of TypeScript declaration files from JavaScript code

“…The TypeScript project provides a guide on how to write high-quality declaration files 9 . The guide explains the main var greet = require ( " ./ greet -settings -module " ) ; greet ({ greeting : " hello world " , duration : 4000 }) ; greet ({ greeting : " hello world " , color : " #00 ff00 " }) ; The Typescript project provides a package dts-gen, which generates a template for a declaration file by analyzing the structure of the module.…”

“…TSTest. TSTest is a tool that checks for mismatches between a declaration file and the JavaScript implementation of the module [9]. It applies feedback-directed random testing for generating type test scripts.…”

Model-based testing of breaking changes in Node.js libraries

“…A well-known problem with semantic versioning is that it requires a specification of the library's API, 12 typically in the form of documentation, such that a client knows exactly what the library expects and what it produces, and this is often an unrealistic requirement [1]. Without such a specification, any change to the library that breaks a client might as well be classified as the client not using the library as the library developer intended.…”

“…JavaScript library developers can choose to write TypeScript declarations that define the public APIs of their libraries. However, declaration files are often full of errors and rarely kept up-to-date making them unsuitable for breaking change detection [12].…”

Programming Technologies for the Development of Web-Based Platform for Digital Psychological Tools

“…Developing large Single-Page Applications (SPA) based on pure JavaScript on the client side is a difficult and inefficient process, so it is needed to use frameworks that define the application structure and have a basic set of components [23][24][25].…”