Firebase ReferenceError: PostData is not defined - node.js

Question

I am trying to create an elastic search cloud Firebase function but am having some error in the firebase functions. The error references to the index.js code but i don't know where am going wrong. Where could i have gone wrong in the index.js code??
const functions = require('firebase-functions');
const request = require('request-promise')
exports.indexPostsToElastic = functions.database.ref('/posts/{post_id}')
.onWrite((change,context) =>{
let postData = change.after.val();
let post_id = context.params.post_id;
console.log('Indexing post',PostData);
let elasticSearchConfig = functions.config().elasticSearch;
let elasticSearchUrl = elasticSearchConfig.Url + 'posts/' + post_id;
let elasticSearchMethod = postData ? 'POST' : 'DELETE';
let elasticSearchRequest = {
method:elasticSearchMethod,
url: elasticSearchUrl,
auth:{
username : elasticSearchConfig.username,
password : elasticSearchConfig.password,
},
body: postData,
json : true
};
return request(elasticSearchRequest).then(response => {
return console.log("ElasticSearch response", response);
})
});
Below is how the error reads in my Firebase
ReferenceError: PostData is not defined
at exports.indexPostsToElastic.functions.database.ref.onWrite (/user_code/index.js:10:31)
at cloudFunctionNewSignature (/user_code/node_modules/firebase-functions/lib/cloud-functions.js:114:23)
at cloudFunction (/user_code/node_modules/firebase-functions/lib/cloud-functions.js:144:20)
at /var/tmp/worker/worker.js:827:24
at process._tickDomainCallback (internal/process/next_tick.js:135:7)
I expect the function execution to finish withe status successful but its finishing with an error.

Answer 1

Change this:
console.log('Indexing post', PostData);
Into this:
console.log('Indexing post', postData);