add dependencies

typescript has included some deps, install deps below

  1. ts-node
  2. ts-jest

add config file

ts-jest support .ts config, just add file jest.config.ts to project root dir.

u have to told jest to use ts-jest to compile before runing, so config {preset: 'ts-jest'}.

the content like:

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import type { Config } from '@jest/types';
const config: Config.InitialOptions = {
    preset: 'ts-jest'
};
export default config;

test

u can just run:

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npm jest

by default, it will run all *.test.ts files which in <root_dir>/test

see more ts-jest config options at https://kulshekhar.github.io/ts-jest/docs/

test single file

in common, we don’t want run all test files.

u can add filename after command ‘jest’

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npm jest filename_with_extension

see more jest command options at https://jestjs.io/docs/cli

config vscode to run jest in debug view

add configurations in .vscode/launch.json

  • jest current opened file

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    {
        "type": "node",
        "request": "launch",
        "name": "Jest Current File",
        "program": "${workspaceFolder}/node_modules/.bin/jest",
        "args": [
            "${fileBasenameNoExtension}",
        ],
        "console": "integratedTerminal",
        "internalConsoleOptions": "neverOpen",
        "disableOptimisticBPs": true,
        "windows": {
            "program": "${workspaceFolder}/node_modules/jest/bin/jest",
        }
    }

  • jest all files

remove prop:args above, see jest cli docs and vscode launch debug