1. A method for asynchronous code testing in an Integrated Development Environment (IDE), said method comprising: a processor of a computer creating an input code in a database pursuant to inputs provided by a user through a source code editor, wherein the IDE comprises the source code editor, an impact analyzer, a test case launcher, and a graphical user interface (GUI), and wherein the database is coupled to the computer hosting the IDE; generating a test case list from the input code by use of the impact analyzer, wherein the impact analyzer runs concurrently with the source code editor such that the test case list is generated immediately after the user modifies a code block of the input code, wherein each test case of the test case list comprises at least one test case comprising a respective test case identifier and a respective launching priority, wherein the respective launching priority quantifies how strongly each test case is associated with the modified code block, said each test case is uniquely identified by the respective test case identifier; producing a test run result for the modified code block by asynchronously running said at least one test case of the test case list by use of the test case launcher based on the respective launching priority of each test case; and communicating the test run result to the user via the GUI.