Skip to main content

jest.config.ts

jest.config.ts - Overview​

  1. Overview

This file configures Jest, a JavaScript testing framework, for a TypeScript project. It specifies various settings such as coverage reporting, module resolution, transformations, and test environment.

  1. Detailed Documentation

The file exports a configuration object for Jest.

  • Purpose: Defines the Jest configuration.
  • Returns: A Config.InitialOptions object that configures Jest.

config object​

  • Purpose: This object holds all the configuration options for Jest.

    • clearMocks:
      • Purpose: Automatically clear mock calls, instances and results before every test.
      • Type: boolean
      • Returns: void
    • coverageDirectory:
      • Purpose: The directory where Jest should output its coverage files.
      • Type: string
      • Returns: void
    • coverageReporters:
      • Purpose: A list of reporter names that Jest uses when writing coverage results.
      • Type: string[]
      • Returns: void
    • collectCoverageFrom:
      • Purpose: An array of glob patterns indicating a set of files for which coverage information should be collected.
      • Type: string[]
      • Returns: void
    • moduleFileExtensions:
      • Purpose: An array of file extensions that Jest should treat as modules.
      • Type: string[]
      • Returns: void
    • modulePathIgnorePatterns:
      • Purpose: An array of regex patterns that Jest uses to detect module paths to ignore.
      • Type: string[]
      • Returns: void
    • moduleNameMapper:
      • Purpose: An object mapping module names to alternative module paths. Used for mocking CSS and MD files.
      • Type: { [key: string]: string }
      • Returns: void
    • globals:
      • Purpose: An object of global variables that will be available in the testing environment. Configures ts-jest to use ESM.
      • Type: { [key: string]: any }
      • Returns: void
    • testMatch:
      • Purpose: An array of glob patterns Jest uses to find test files.
      • Type: string[]
      • Returns: void
    • preset:
      • Purpose: A string that points to a Jest preset.
      • Type: string
      • Returns: void
    • transform:
      • Purpose: An object to define transformers.
      • Type: { [key: string]: string }
      • Returns: void
    • transformIgnorePatterns:
      • Purpose: An array of regex patterns that Jest uses to detect files to transform.
      • Type: string[]
      • Returns: void
    • setupFilesAfterEnv:
      • Purpose: An array of module paths that will be run some code to configure or set up the testing environment before each test.
      • Type: string[]
      • Returns: void
    • testPathIgnorePatterns:
      • Purpose: An array of regex patterns that Jest uses to detect test paths to ignore.
      • Type: string[]
      • Returns: void
    • moduleDirectories:
      • Purpose: An array of directory names to be searched recursively up the tree.
      • Type: string[]
      • Returns: void
    • testEnvironment:
      • Purpose: The test environment that will be used for testing.
      • Type: string
      • Returns: void
    • testEnvironmentOptions:
      • Purpose: Options for the test environment.
      • Type: { [key: string]: any }
      • Returns: void
    • coverageThreshold:
      • Purpose: An object that specifies the thresholds for coverage metrics.
      • Type: { [key: string]: any }
      • Returns: void
  1. Code Examples

None

  1. Clarity and Accuracy

The documentation is based on the code provided.

Include in Getting Started: NO