add support for background functions in api pages only

README.md

@@ -48,6 +48,7 @@ The plugin can be found on [npm here](https://www.npmjs.com/package/@netlify/plu
   - [Preview Locally](#preview-locally)
   - [Custom Netlify Redirects](#custom-netlify-redirects)
   - [Custom Netlify Functions](#custom-netlify-functions)
+  - [Background Functions](#background-functions)
   - [Using Netlify Identity](#using-netlify-identity)
 - [Caveats](#caveats)
   - [Fallbacks for Pages with `getStaticPaths`](#fallbacks-for-pages-with-getstaticpaths)
@@ -223,7 +224,12 @@ Currently, there is no support for redirects set in your `netlify.toml` file.
 ### Custom Netlify Functions
 
 `next-on-netlify` creates one Netlify Function for each of your
-SSR pages and API endpoints. It is currently not possible to create custom Netlify Functions. This feature is on our list to do.
+SSR pages and API endpoints. Currently, you can only create custom Netlify functions using [@netlify/plugin-nextjs](https://github.com/netlify/netlify-plugin-nextjs#custom-netlify-functions).
+
+### Background Functions
+
+If your Next.js API page/route ends in `-background`, it will be treated as a [Netlify background function](https://docs.netlify.com/functions/background-functions/).
+Note: background functions are only available on certain plans.
 
 ### Using Netlify Identity
 

lib/helpers/getNetlifyFunctionName.js

@@ -5,7 +5,7 @@ const path = require("path");
 // The function name will be next_directory_subdirectory_[id]
 // We do this because every function needs to be at the top-level, i.e.
 // nested functions are not allowed.
-const getNetlifyFunctionName = (filePath) => {
+const getNetlifyFunctionName = (filePath, isApiPage) => {
   // Remove pages/ from file path:
   // pages/directory/page.js > directory/page.js
   const relativeFilePath = path.relative("pages", filePath);
@@ -24,7 +24,16 @@ const getNetlifyFunctionName = (filePath) => {
   // Netlify Function names may not contain periods or square brackets.
   // To be safe, we keep only alphanumeric characters and underscores.
   // See: https://community.netlify.com/t/failed-to-upload-functions-file-function-too-large/3549/8
-  functionName = functionName.replace(/[^\w\d]/g, "");
+  const cleanNameRegex = new RegExp(/[^\w\d]/g);
+  // Allow users to use background functions for /api pages *only*
+  // Note: this means that there is a chance a Next on Netlify user could
+  // unknowingly create a background function if they're not familiar with them
+  // and their syntax
+  const allowBackgroundRegex = new RegExp(/[^\w\d-]|-(?!background$)/g);
+  functionName = functionName.replace(
+    isApiPage ? allowBackgroundRegex : cleanNameRegex,
+    ""
+  );
 
   return functionName;
 };

lib/helpers/setupNetlifyFunctionForPage.js

@@ -6,14 +6,25 @@ const {
   FUNCTION_TEMPLATE_PATH,
 } = require("../config");
 const getNetlifyFunctionName = require("./getNetlifyFunctionName");
+const { logItem } = require("./logger");
 
 // Create a Netlify Function for the page with the given file path
-const setupNetlifyFunctionForPage = ({ filePath, functionsPath }) => {
+const setupNetlifyFunctionForPage = ({
+  filePath,
+  functionsPath,
+  isApiPage,
+}) => {
   // Set function name based on file path
-  const functionName = getNetlifyFunctionName(filePath);
+  const functionName = getNetlifyFunctionName(filePath, isApiPage);
   const functionDirectory = join(functionsPath, functionName);
 
-  // Copy function template
+  if (isApiPage && functionName.endsWith("-background")) {
+    logItem(
+      `👁 Setting up API page ${functionName} as a Netlify background function`
+    );
+  }
+
+  // Copy function templates
   const functionTemplateCopyPath = join(
     functionDirectory,
     `${functionName}.js`

lib/pages/api/redirects.js

@@ -3,7 +3,7 @@ const pages = require("./pages");
 
 const redirects = pages.map(({ route, filePath }) => ({
   route,
-  target: `/.netlify/functions/${getNetlifyFunctionName(filePath)}`,
+  target: `/.netlify/functions/${getNetlifyFunctionName(filePath, true)}`,
 }));
 
 module.exports = redirects;

lib/pages/api/setup.js

@@ -12,7 +12,7 @@ const setup = (functionsPath) => {
   // Create Netlify Function for every page
   pages.forEach(({ filePath }) => {
     logItem(filePath);
-    setupNetlifyFunctionForPage({ filePath, functionsPath });
+    setupNetlifyFunctionForPage({ filePath, functionsPath, isApiPage: true });
   });
 };
 

tests/__snapshots__/defaults.test.js.snap

@@ -24,6 +24,7 @@ exports[`Routing creates Netlify redirects 1`] = `
 /_next/data/%BUILD_ID%/getStaticProps/withFallbackBlocking/4.json  /.netlify/functions/next_getStaticProps_withFallbackBlocking_id  200!  Cookie=__prerender_bypass,__next_preview_data
 /_next/data/%BUILD_ID%/getStaticProps/withRevalidate/1.json  /.netlify/functions/next_getStaticProps_withRevalidate_id  200
 /_next/data/%BUILD_ID%/getStaticProps/withRevalidate/2.json  /.netlify/functions/next_getStaticProps_withRevalidate_id  200
+/api/hello-background  /.netlify/functions/next_api_hello-background  200
 /api/static  /.netlify/functions/next_api_static  200
 /getServerSideProps/static  /.netlify/functions/next_getServerSideProps_static  200
 /getStaticProps/1  /.netlify/functions/next_getStaticProps_id  200!  Cookie=__prerender_bypass,__next_preview_data

tests/__snapshots__/i18n.test.js.snap

@@ -23,6 +23,7 @@ exports[`Routing creates Netlify redirects 1`] = `
 /_next/data/%BUILD_ID%/es/getStaticProps/static.json  /.netlify/functions/next_getStaticProps_static  200!  Cookie=__prerender_bypass,__next_preview_data
 /_next/data/%BUILD_ID%/es/getStaticProps/with-revalidate.json  /.netlify/functions/next_getStaticProps_withrevalidate  200
 /_next/data/%BUILD_ID%/getServerSideProps/static.json  /.netlify/functions/next_getServerSideProps_static  200
+/api/hello-background  /.netlify/functions/next_api_hello-background  200
 /api/static  /.netlify/functions/next_api_static  200
 /en  /.netlify/functions/next_index  200
 /en/getServerSideProps/static  /.netlify/functions/next_getServerSideProps_static  200

tests/defaults.test.js

@@ -129,6 +129,15 @@ describe("API Pages", () => {
         join(functionsDir, "next_api_shows_params", "next_api_shows_params.js")
       )
     ).toBe(true);
+    expect(
+      existsSync(
+        join(
+          functionsDir,
+          "next_api_hello-background",
+          "next_api_hello-background.js"
+        )
+      )
+    ).toBe(true);
   });
 });
 

tests/fixtures/pages/api/hello-background.js

@@ -0,0 +1,5 @@
+export default (req, res) => {
+  res.setHeader("Content-Type", "application/json");
+  res.status(200);
+  res.json({ message: "hello world :)" });
+};