When collection is created, the documents are added to it at once - node.js

Question

Still learning firestore, i want to write a function which would create multiple documents upon the creation of a collection at once. So i wrote this code to try it out. i saw the code as an answer to something similar.
const fsRef = admin.firestore();
export const moreCreations = functions.firestore
.document(
"dev_env/schools/school_collections/KithAndKin7394/students/{userID}"
)
.onCreate((snap, context) => {
const newSchoolRef = fsRef
.collection("dev_env")
.doc("schools")
.collection("school_collections")
.doc("KithAndKin7394")
.collection("students")
.doc(snap.id);
// Trying something on documents
const documentIds = [
'CRK_IRK',
'PHE',
'agricScience',
'basicScience',
'basicTechnology',
'businessStudies',
'computerStudies',
'creativeArts',
'english',
'frenchLanguage',
'hausaLanguage',
'homeEconomics',
'iboLanguage',
'maths',
'socialStudies',
'yoruba'
];
const batch = fsRef.batch();
const data ={};
const setbatch = documentIds.forEach(docId => {
batch.set(newSchoolRef.collection('JSS1').doc('${docId}'), data);
})
batch. commit().then(response => {
console.log('Success');
}).catch(err => {
console.error(err);
})
});
I am getting these errors:
i deploying functions
Running command: npm --prefix "$RESOURCE_DIR" run lint
> functions# lint C:\brighterbrains\functions
> tslint --project tsconfig.json
ERROR: C:/brighterbrains/functions/src/index.ts:168:23 - Expression has type `void`. Put it on its own line as a statement.
npm ERR! code ELIFECYCLE
npm ERR! errno 2
npm ERR! functions# lint: `tslint --project tsconfig.json`
npm ERR! Exit status 2
npm ERR!
npm ERR! Failed at the functions# lint script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:
npm ERR! C:\Users\dell\AppData\Roaming\npm-cache\_logs\2020-03-30T02_04_34_455Z-debug.log
Error: functions predeploy error: Command terminated with non-zero exit code2
What i want is when the collection "JSS1" is created, the documents "documentsId" are added to it at once. The code is from this forum but it is not working. Please can anyone point my mistake and help with me with the corrections? The documentation doesn't do or say anything about such actions.
Thanks in advance.

Answer 1

Remove const setbatch = from before the forEach(). It doesn't have a return value.

Answer 2

I have solved it. Below is the updated code:
export const moreCreations = functions.firestore
.document(
"dev_env/schools/school_collections/KithAndKin7394/students/{userID}"
)
.onCreate((snap, context) => {
const newSchoolRef = fsRef
.collection("dev_env")
.doc("schools")
.collection("school_collections")
.doc("KithAndKin7394")
.collection("students")
.doc(snap.id);
// Trying something on documents
const documentIds = [
'CRK_IRK',
'PHE',
'agricScience',
'basicScience',
'basicTechnology',
'businessStudies',
'computerStudies',
'creativeArts',
'english',
'frenchLanguage',
'hausaLanguage',
'homeEconomics',
'iboLanguage',
'maths',
'socialStudies',
'yoruba'
];
const batch = fsRef.batch();
const data ={};
documentIds.forEach(docId => {
batch.set(newSchoolRef.collection('JSS1').doc(docId), data);
})
batch.commit().then(response => {
console.log('Success');
}).catch(err => {
console.error(err);
})
});
It deployed successfully and upon creation of a document, the collection JSS1 is automatically created with the documents under the documentsId array automatically added.
I wanna thank #samthecodingman for helping me spot the area i need to edit. And #DougStevenson too.