Why is my variable not altering after changing once - node.js

Question

I am making a simple web-application that fetches the definition of a word using an API. There's definitely nothing wrong with the API keys because the application semi-works - Once i search for a word for the first time it will give back a result however, on the second try and onwards the definition doesn't change (The definition matches the first word instead of the latest one).
I'm thinking it has something to do with scopes and constants but I tried that already (Change var to let or const). I've read online about that callback functions are Asynchronous but I don't think that's the issue at all.
app.get('/definition/:word', (req, res) => {
if (word !== req.params.word) {
console.log("If statement");
word = req.params.word;
console.log(word);
word = word.toLowerCase();
}
options.path += '/' + language_code + '/' + word + '?fields=definitions' +
'&strictMatch=true';
url += options.path;
console.log(options.path);
request(url, options, (error, response, body) => {
if (error) {
res.redirect('/error');
} else {
let statusCode = (response.statusCode);
console.log(statusCode);
if (statusCode === 200) {
let data = JSON.parse(body);
console.log(definition);
definition = String(data.results[0].lexicalEntries[0].entries[0].senses[0].definitions);
console.log(definition);
res.render('definition', {
wordTitle: word,
definitions: definition
});
} else {
res.redirect('/error');
}
}
});
});
app.post('/', (req, res) => {
console.log("Post");
word = String(req.body.Word);
word = word.toLowerCase();
console.log(word);
res.redirect('/definition/' + word);
});
EDIT 1:
full index.js source code: https://github.com/NikodemBieniek/dictionary/blob/myfeature/server/index.js

Answer 1

I think the issue is with below line of code
options.path += '/' + language_code + '/' + word + '?fields=definitions' +
'&strictMatch=true';
So first time when you make API call and pass a param as 'XYZ'
the value in option.path will be
/en-gb/xyz?fields=definition&strictMatch=true
The second time you make API call and pass a param as 'PQR' the value in option.path will be
/en-gb/xyz?fields=definition&strictMatch=true/en-gb/pqr?fields=definition&strictMatch=true
Because you are doing string concatination.
The possible fix can be
app.get('/definition/:word', (req, res) => {
if (word !== req.params.word) {
console.log("If statement");
word = req.params.word;
console.log(word);
word = word.toLowerCase();
}
const options = {
host: 'https://od-api.oxforddictionaries.com',
port: '443',
path: '/api/v2/entries',
method: "GET",
headers: {
'app_id': process.env.APP_ID,
'app_key': process.env.APP_KEY,
}
};
options.path += '/' + language_code + '/' + word + '?fields=definitions' +
'&strictMatch=true';
let url = `${options.host}${options.path}`;
request(url, options, (error, response, body) => {
if (error) {
res.redirect('/error');
} else {
let statusCode = (response.statusCode);
console.log(statusCode);
if (statusCode === 200) {
let data = JSON.parse(body);
definition = String(data.results[0].lexicalEntries[0].entries[0].senses[0].definitions);
res.render('definition', {
wordTitle: word,
definitions: definition
});
} else {
res.redirect('/error');
}
}
});
});
Remove option and URL declared on line 12 and 26