Add Pre And Post Hooks For Yarn Scripts as a JavaScript TIL

javascript/pre-and-post-hooks-for-yarn-scripts.md

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+# Pre And Post Hooks For Yarn Scripts
+
+In [yarn](https://classic.yarnpkg.com/) v1, there is a special syntax for
+script names that allows you to define pre and post hooks.
+
+For instance, if you have a `build` script, you can define a `prebuild` and/or
+a `postbuild` script as well. Then, anytime you invoke `yarn build`, the
+`prebuild` script will be automatically run before `build` and the `postbuild`
+script be automatically run after `build`.
+
+This `pre{script}` and `post{script}` syntax works for any script.
+
+```json
+{
+  "scripts": {
+    "predeploy": "node pre-deploy-steps"
+    "deploy": "my-framework deploy",
+    "postdeploy": "node post-deploy-steps"
+  }
+}
+```
+
+This syntax may lead to unexpected script invocations. For instance, a
+`preserve` script will run ahead of a `serve` script even though those were
+probably intended to be unrelated scripts. This is, in part, why this syntax is
+no longer support in yarn v2.
+
+[source](https://classic.yarnpkg.com/lang/en/docs/cli/run/#toc-yarn-run-script)