Husky prepare script failing firebase function deployment

Question

I have installed husky in my npm project as a prepare script like below

{
  "name": "functions",
  "scripts": {
    "build": "tsc",
    "start": "npm run serve",
    "deploy": "firebase deploy --only functions",
    "prepare": "husky install functions/.husky"
  }
  "dependencies": {
    "firebase-admin": "^11.4.1",
    "firebase-functions": "^4.1.1",
  },
  "devDependencies": {
    "husky": "^8.0.2",
    "typescript": "^4.9.4"
  }
}

husky is declared as devDependencies as this npm module is only required while local development and has no need in runtime app.

So when I run npm run deploy, I get the below error

i  functions: updating Node.js 16 function funName(us-central1)...
Build failed:

> prepare
> husky install functions/.husky

sh: 1: husky: not found
npm ERR! code 127
npm ERR! path /workspace
npm ERR! command failed
npm ERR! command sh -c -- husky install functions/.husky

This error clearly states that husky is not installed.

One possible solution is to create a prepare.js script which checks if the script is running while in local development or in the firebase server(to prepare the project) and then conditionally run the husky npm module command

Answer 1

I just ran into this exact same issue but with tsc. I'm not sure why, but the prepare script is also run in the cloud function (not just locally) while deploying. However, considering you likely have the node_modules directory in the functions.ignore list in the firebase.json, the node_modules directory doesn't get uploaded as part of the deployment and so the husky package isn't visible to the script when it gets run in the cloud function environment.

You likely don't need the husky script to be run in the function environment either way, so you can add a condition to check for an environment variable that is usually set in the function environment (I am using the GOOGLE_FUNCTION_TARGET environment variable in my case), and only run the command if that environment is not set. You also need to wrap this in a bash script instead of adding it inline in the package.json because of how the prepare script is run.

For example, here's the content of my scripts/prepare.sh file.

#!/bin/bash
set -o verbose

# Only run if the GOOGLE_FUNCTION_TARGET is not set
if [[ -z "$GOOGLE_FUNCTION_TARGET" ]]; then
    npm run build
fi

Then I use it in my package.json prepare script:

// ...
"prepare": "./scripts/prepare.sh",
// ...

There's potentially a better solution to this, but this is how I got it to work for me. Hope this helps!