Fix require('next') in production

helpers/requirePeerDependency.js

@@ -0,0 +1,13 @@
+// In production, Build plugins cannot currently require peer dependencies
+// without this hack.
+// See https://github.com/netlify/netlify-plugin-nextjs/issues/55
+// TODO: remove once https://github.com/netlify/pod-the-builder/issues/102 is solved
+const requirePeerDependency = function (IS_LOCAL, modulePath) {
+  if (!IS_LOCAL) {
+    return require(require.resolve(modulePath, { paths: ['.'] }))
+  }
+
+  return require(modulePath)
+}
+
+module.exports = requirePeerDependency

helpers/validateNextUsage.js

@@ -1,19 +1,21 @@
 const { lt: ltVersion, gte: gteVersion } = require('semver')
 const { yellowBright } = require('chalk')
 
+const requirePeerDependency = require('./requirePeerDependency')
+
 // Ensure Next.js is available.
 // We use `peerDependencies` instead of `dependencies` so that users can choose
 // the Next.js version. However, this requires them to install "next" in their
 // site.
-const validateNextUsage = function (failBuild) {
+const validateNextUsage = function (failBuild, IS_LOCAL) {
   if (!hasPackage('next')) {
     return failBuild(
       'This site does not seem to be using Next.js. Please run "npm install next" or "yarn next" in the repository.',
     )
   }
 
   // Old Next.js versions are not supported
-  const { version } = require('next/package.json')
+  const { version } = requirePeerDependency(IS_LOCAL, 'next/package.json')
   if (ltVersion(version, MIN_VERSION)) {
     return failBuild(`Please upgrade to Next.js ${MIN_VERSION} or later`)
   }

index.js

@@ -7,6 +7,7 @@ const makeDir = require('make-dir')
 
 const isStaticExportProject = require('./helpers/isStaticExportProject')
 const validateNextUsage = require('./helpers/validateNextUsage')
+const requirePeerDependency = require('./helpers/requirePeerDependency')
 
 const pWriteFile = util.promisify(fs.writeFile)
 
@@ -15,10 +16,10 @@ const pWriteFile = util.promisify(fs.writeFile)
 // - Between the build and postbuild steps, any functions are bundled
 
 module.exports = {
-  async onPreBuild({ netlifyConfig, packageJson, utils }) {
+  async onPreBuild({ netlifyConfig, packageJson, utils, constants: { IS_LOCAL } }) {
     const { failBuild } = utils.build
 
-    validateNextUsage(failBuild)
+    validateNextUsage(failBuild, IS_LOCAL)
 
     if (Object.keys(packageJson).length === 0) {
       return failBuild(`Could not find a package.json for this project`)
@@ -45,8 +46,8 @@ module.exports = {
     if (nextConfigPath !== undefined) {
       // We cannot load `next` at the top-level because we validate whether the
       // site is using `next` inside `onPreBuild`.
-      const { PHASE_PRODUCTION_BUILD } = require('next/constants')
-      const { default: loadConfig } = require('next/dist/next-server/server/config')
+      const { PHASE_PRODUCTION_BUILD } = requirePeerDependency(IS_LOCAL, 'next/constants')
+      const { default: loadConfig } = requirePeerDependency(IS_LOCAL, 'next/dist/next-server/server/config')
 
       // If the next config exists, fail build if target isnt in acceptableTargets
       const acceptableTargets = ['serverless', 'experimental-serverless-trace']
@@ -66,7 +67,7 @@ module.exports = {
       console.log(`** Adding next.config.js with target set to 'serverless' **`)
     }
   },
-  async onBuild({ constants: { PUBLISH_DIR, FUNCTIONS_SRC = DEFAULT_FUNCTIONS_SRC } }) {
+  async onBuild({ constants: { PUBLISH_DIR, FUNCTIONS_SRC = DEFAULT_FUNCTIONS_SRC, IS_LOCAL } }) {
     console.log(`** Running Next on Netlify package **`)
 
     await makeDir(PUBLISH_DIR)
@@ -75,7 +76,11 @@ module.exports = {
     // top-level because we validate whether the site is using `next`
     // inside `onPreBuild`.
     const nextOnNetlify = require('next-on-netlify')
-    nextOnNetlify({ functionsDir: FUNCTIONS_SRC, publishDir: PUBLISH_DIR })
+    nextOnNetlify({
+      functionsDir: FUNCTIONS_SRC,
+      publishDir: PUBLISH_DIR,
+      requirePeerDependency: requirePeerDependency.bind(undefined, IS_LOCAL),
+    })
   },
 }
 

test/index.js

@@ -92,6 +92,7 @@ describe('preBuild()', () => {
         netlifyConfig: {},
         packageJson,
         utils,
+        constants: {},
       }),
     ).rejects.toThrow(
       `This plugin does not support sites that manually use next-on-netlify. Uninstall next-on-netlify as a dependency to resolve.`,
@@ -107,6 +108,7 @@ describe('preBuild()', () => {
         netlifyConfig: {},
         packageJson,
         utils,
+        constants: {},
       }),
     ).rejects.toThrow(
       `This plugin does not support sites that manually use next-on-netlify. Uninstall next-on-netlify as a dependency to resolve.`,