Static Analysis Testing JavaScript Applications

Auto-format all files and validate relevant files in a precommit script with lint-staged

In this example, the editor.formatOnSave was turned off for the demonstration.

With an example of bad formatting, the pre-commit hook that validate format fails. We can remedy this with lint-staged.

$ npm i -D lint-staged
$ touch .lintstagedrc
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In .lintstagedrc:

{
    "*.+(js|ts|tsx)": [
        "eslint"
    ],
    "**/*.+(js|json|ts|tsx)": [
        "prettier --write",
        "git add"
    ]
}
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The example then updates .huskyrc to change the pre-commit hook to lint-staged.

Run multiple npm scripts in parallel with npm-run-all

$ npm i -D npm-run-all
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The example npm validate script was the updated:

{
    "scripts": {
        "validate": "npm-run-all --parallel check-types check-format lint build"
    }
}
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