TypeScript – Element implicitly has an ‘any’ type […] No index signature with a parameter of type ‘string’ was found on type
I’m struggling to get over an error on TS.
I define value (below in the code) according 2 interfaces that I created (WalletInformationsEdit and UserInformationsEdit)
The problem that I encounter is at the line right after the DB query, value[field] is underlined saying :
Element implicitly has an 'any' type because expression of type 'string' can't be used to index type 'WalletInformationsEdit | UserInformationsEdit'. No index signature with a parameter of type 'string' was found on type 'WalletInformationsEdit | UserInformationsEdit'.
I have find 2 solutions to avoid this error message, but I am not ok because they make my code less protected:
1/ In TS config, if I take off “strict”: true and “noImplicitAny”: true -> working
2/ if I define value with “any” type, -> working
But both are not worth it, I suppose.
Do you have any recommandation to handle this case ?
Thanks in advance,
Paul
public async update(value: WalletInformationsEdit | UserInformationsEdit): Promise<any> {
try {
// saving id before elem treatment
const keepId = value.id
delete value.id
let filterFields = []
for (let elem of Object.keys(value)) {
filterFields.push(elem)
}
let i = 0;
let updateList = [];
for (const field of filterFields) {
updateList.push(`"${field}" = $${++i}`);
}
const preparedQuery = {
text: `UPDATE "${this.constructor.name.toLowerCase()}" SET
${updateList.join()}
WHERE id = $${++i}
RETURNING *
`,
values: [...filterFields.map((field) => value[field]), keepId],
};
const result = await db.query(preparedQuery);
return result.rows[0]
} catch (error) {
throw new Error(error.message)
}
}
WalletInformationsEdit and UserInformationsEdit interfaces
export interface UserInformationsEdit {
id?: number,
email?: string,
password?: string,
country?: string
}
export interface WalletInformationsEdit {
id?: number,
name?: string,
is_default?: boolean,
}
Answer
I finally find the answer, to declare the index signature in my case, i had to declare it this way
export interface WalletInformationsEdit {
[key: string]: number | string | boolean | undefined;
id?: number,
name?: string,
is_default?: boolean
}
[key: string] -> index is read as a string
: number | string | boolean | undefined -> each type that composed my interface + undefined because properties are optional
thanks @DigitalDrifter for the link 🙂