Why Am I Getting Fetch Errors During Next.js Static Site Compilation with `getStaticProps` and `getStaticPaths`?

Uncovering the Cause of Fetch Errors in Next.js Static Site Compilation

When using Next.js to construct a static website, it's imperative to know the source of certain errors that might arise during the build process. In this instance, we'll address the specific problem faced during npm run build when utilizing both getStaticProps and getStaticPaths to retrieve data from an API route.

Error Details

The primary error being encountered is associated with an invalid JSON response received from the API route when executing npm run build. This response appears to originate from the API route pages/api/products/[slug].js.

Possible Causes

1. Incorrect API Routing: Inspect the implementation of pages/api/products/[slug].js thoroughly to ascertain whether the data is fetched and processed appropriately. If there are any mistakes in this code, they may cause the invalid JSON response.
2. API Route Availability: Keep in mind that API routes are not accessible during the build process. Therefore, if your getStaticProps or getStaticPaths functions rely on API routes to obtain data, this can lead to errors.

Recommended Resolution

To rectify this issue, consider refactoring your code in the following manner:

1. Utilize Server-Side Logic: Since getStaticProps operates exclusively on the server-side, you can bypass API routes by integrating the server-side logic directly into these functions. This eliminates the need to fetch data from an API route, and instead permits you to retrieve data directly.
2. Data Retrieval from Server: Directly access the data source, which in this case is stored in data/products, within getStaticProps and getStaticPaths. Modify your functions as follows:

// /pages/product/[slug]

import db from '../../../data/products';

// Remaining code.

export const getStaticProps = async ({ params: { slug }, locale }) = {
  const result = db.filter((item) => item.slug === slug);
  const data = result.filter((item) => item.locale === locale)[0];
  const { title, keywords, description } = data;
  return {
    props: {
      data,
      description,
      keywords,
      title,
    },
  };
};

export const getStaticPaths = async () = {
  const paths = db.map(({ slug, locale }) => ({
    params: { slug: slug },
    locale,
  }));
  return {
    fallback: true,
    paths,
  };
};

By adopting these changes, you'll remove the reliance on the API route, resolve the invalid JSON response error, and allow for seamless static website compilation.

The above is the detailed content of Why Am I Getting Fetch Errors During Next.js Static Site Compilation with `getStaticProps` and `getStaticPaths`?. For more information, please follow other related articles on the PHP Chinese website!