Typescritp error in this.$apollo.mutate.update

[abritopach]

Hi, after upgrading an existing project to a newer version I get the following error:

TS2459: Type '{ [key: string]: any; } | undefined' has no property 'deletePost' and no string index signature.

Relevant code:

this.$apollo
            .mutate({
                mutation: DELETE_POST_MUTATION,
                variables: {
                    id: item.id,
                },
                update: (store, { data: { deletePost } }) => {
                    // Read data from cache for the allPosts query.
                    let data = store.readQuery({ query: USER_QUERY, variables: { id: this.loggedUser.id} }) || {};
                    console.log('data', data);
                    // Delete post from the data.
                    (data as any)['User']['posts'] = (data as any)['User']['posts'].filter((i: any) => i.id !== deletePost.id);

                    // Write data back to the cache for the allPosts query.
                    store.writeQuery({ query: USER_QUERY, data })
                }
            })
            .then(response => {
                console.log(response);
            })

Any suggestions?

Thanks!!

[NattapongSiri]

My guess is that DELETE_POST_MUTATION doesn't return deletePost object.

[joe-re]

Because data could be undefined when something error was caused.
To avoid type error you have to check what data is not undefined at the first.

                update: (store, { data }) => {
                    if (!data) {
                      throw new Error('data is undefined')
                    }
                    const deletePost = data.deletePost
                    // ...
                }