Add entrypoint tracing

packages/next/build/index.ts

@@ -662,6 +662,8 @@ export default async function build(
     const serverPropsPages = new Set<string>()
     const additionalSsgPaths = new Map<string, Array<string>>()
     const additionalSsgPathsEncoded = new Map<string, Array<string>>()
+    const pageTraceIncludes = new Map<string, Array<string>>()
+    const pageTraceExcludes = new Map<string, Array<string>>()
     const pageInfos = new Map<string, PageInfo>()
     const pagesManifest = JSON.parse(
       await promises.readFile(manifestPath, 'utf8')
@@ -820,6 +822,11 @@ export default async function build(
                   )
                 })
 
+                if (config.experimental.nftTracing) {
+                  pageTraceIncludes.set(page, workerResult.traceIncludes || [])
+                  pageTraceExcludes.set(page, workerResult.traceExcludes || [])
+                }
+
                 if (
                   workerResult.isStatic === false &&
                   (workerResult.isHybridAmp || workerResult.isAmpOnly)
@@ -958,6 +965,63 @@ export default async function build(
       )
     }
 
+    if (config.experimental.nftTracing) {
+      const globOrig = require('next/dist/compiled/glob') as typeof import('next/dist/compiled/glob')
+      const glob = (pattern: string): Promise<string[]> => {
+        return new Promise((resolve, reject) => {
+          globOrig(pattern, { cwd: dir }, (err, files) => {
+            if (err) {
+              return reject(err)
+            }
+            resolve(files)
+          })
+        })
+      }
+
+      for (const page of pageKeys) {
+        const includeGlobs = pageTraceIncludes.get(page)
+        const excludeGlobs = pageTraceExcludes.get(page)
+
+        if (!includeGlobs?.length && !excludeGlobs?.length) {
+          continue
+        }
+
+        const traceFile = path.join(
+          distDir,
+          'server/pages',
+          `${page}.js.nft.json`
+        )
+        const traceContent = JSON.parse(
+          await promises.readFile(traceFile, 'utf8')
+        )
+        let includes: string[] = []
+        let excludes: string[] = []
+
+        if (includeGlobs?.length) {
+          for (const includeGlob of includeGlobs) {
+            includes.push(...(await glob(includeGlob)))
+          }
+        }
+
+        if (excludeGlobs?.length) {
+          for (const excludeGlob of excludeGlobs) {
+            excludes.push(...(await glob(excludeGlob)))
+          }
+        }
+
+        const combined = new Set([...traceContent.files, ...includes])
+        excludes.forEach((file) => combined.delete(file))
+
+        await promises.writeFile(
+          traceFile,
+          JSON.stringify({
+            version: traceContent.version,
+            files: [...combined],
+          })
+        )
+      }
+    }
+
     if (serverPropsPages.size > 0 || ssgPages.size > 0) {
       // We update the routes manifest after the build with the
       // data routes since we can't determine these until after build

packages/next/build/utils.ts

@@ -831,6 +831,8 @@ export async function isPageStatic(
   encodedPrerenderRoutes?: string[]
   prerenderFallback?: boolean | 'blocking'
   isNextImageImported?: boolean
+  traceIncludes?: string[]
+  traceExcludes?: string[]
 }> {
   const isPageStaticSpan = trace('is-page-static-utils', parentId)
   return isPageStaticSpan.traceAsyncFn(async () => {
@@ -936,6 +938,8 @@ export async function isPageStatic(
         hasStaticProps,
         hasServerProps,
         isNextImageImported,
+        traceIncludes: config.unstable_includeFiles || [],
+        traceExcludes: config.unstable_excludeFiles || [],
       }
     } catch (err) {
       if (err.code === 'MODULE_NOT_FOUND') return {}

packages/next/build/webpack-config.ts

@@ -38,6 +38,7 @@ import BuildStatsPlugin from './webpack/plugins/build-stats-plugin'
 import ChunkNamesPlugin from './webpack/plugins/chunk-names-plugin'
 import { JsConfigPathsPlugin } from './webpack/plugins/jsconfig-paths-plugin'
 import { DropClientPage } from './webpack/plugins/next-drop-client-page-plugin'
+import { TraceEntryPointsPlugin } from './webpack/plugins/next-trace-entrypoints-plugin'
 import NextJsSsrImportPlugin from './webpack/plugins/nextjs-ssr-import'
 import NextJsSSRModuleCachePlugin from './webpack/plugins/nextjs-ssr-module-cache'
 import PagesManifestPlugin from './webpack/plugins/pages-manifest-plugin'
@@ -1245,6 +1246,12 @@ export default async function getBaseWebpackConfig(
           pagesDir,
         }),
       !isServer && new DropClientPage(),
+      config.experimental.nftTracing &&
+        !isLikeServerless &&
+        isServer &&
+        !dev &&
+        isWebpack5 &&
+        new TraceEntryPointsPlugin({ appDir: dir }),
       // Moment.js is an extremely popular library that bundles large locale files
       // by default due to how Webpack interprets its code. This is a practical
       // solution that requires the user to opt into importing specific locales.

packages/next/build/webpack/plugins/next-trace-entrypoints-plugin.ts

@@ -0,0 +1,253 @@
+import nodePath from 'path'
+import { nodeFileTrace } from 'next/dist/compiled/@vercel/nft'
+import {
+  webpack,
+  isWebpack5,
+  sources,
+} from 'next/dist/compiled/webpack/webpack'
+import { TRACE_OUTPUT_VERSION } from '../../../shared/lib/constants'
+
+const PLUGIN_NAME = 'TraceEntryPointsPlugin'
+const TRACE_IGNORES = [
+  '**/*/node_modules/react/**/*.development.js',
+  '**/*/node_modules/react-dom/**/*.development.js',
+]
+
+function getModuleFromDependency(
+  compilation: any,
+  dep: any
+): webpack.Module & { resource?: string } {
+  if (isWebpack5) {
+    return compilation.moduleGraph.getModule(dep)
+  }
+
+  return dep.module
+}
+
+export class TraceEntryPointsPlugin implements webpack.Plugin {
+  private appDir: string
+  private entryTraces: Map<string, string[]>
+
+  constructor({ appDir }: { appDir: string }) {
+    this.appDir = appDir
+    this.entryTraces = new Map()
+  }
+
+  // Here we output all traced assets and webpack chunks to a
+  // ${page}.js.nft.json file
+  createTraceAssets(compilation: any, assets: any) {
+    const outputPath = compilation.outputOptions.path
+
+    for (const entrypoint of compilation.entrypoints.values()) {
+      const entryFiles = new Set<string>()
+
+      for (const chunk of entrypoint
+        .getEntrypointChunk()
+        .getAllReferencedChunks()) {
+        for (const file of chunk.files) {
+          entryFiles.add(nodePath.join(outputPath, file))
+        }
+        for (const file of chunk.auxiliaryFiles) {
+          entryFiles.add(nodePath.join(outputPath, file))
+        }
+      }
+      // don't include the entry itself in the trace
+      entryFiles.delete(
+        nodePath.join(
+          outputPath,
+          `${isWebpack5 ? '../' : ''}${entrypoint.name}.js`
+        )
+      )
+      const traceOutputName = `${isWebpack5 ? '../' : ''}${
+        entrypoint.name
+      }.js.nft.json`
+      const traceOutputPath = nodePath.join(outputPath, traceOutputName)
+
+      assets[traceOutputName] = new sources.RawSource(
+        JSON.stringify({
+          version: TRACE_OUTPUT_VERSION,
+          files: [...entryFiles, ...this.entryTraces.get(entrypoint.name)!].map(
+            (file) => {
+              return nodePath
+                .relative(traceOutputPath, file)
+                .replace(/\\/g, '/')
+            }
+          ),
+        })
+      )
+    }
+  }
+
+  apply(compiler: webpack.Compiler) {
+    if (isWebpack5) {
+      compiler.hooks.compilation.tap(PLUGIN_NAME, (compilation) => {
+        // @ts-ignore TODO: Remove ignore when webpack 5 is stable
+        compilation.hooks.processAssets.tap(
+          {
+            name: PLUGIN_NAME,
+            // @ts-ignore TODO: Remove ignore when webpack 5 is stable
+            stage: webpack.Compilation.PROCESS_ASSETS_STAGE_SUMMARIZE,
+          },
+          (assets: any) => {
+            this.createTraceAssets(compilation, assets)
+          }
+        )
+      })
+    } else {
+      compiler.hooks.emit.tap(PLUGIN_NAME, (compilation: any) => {
+        this.createTraceAssets(compilation, compilation.assets)
+      })
+    }
+
+    compiler.hooks.compilation.tap(PLUGIN_NAME, (compilation) => {
+      compilation.hooks.finishModules.tapAsync(
+        PLUGIN_NAME,
+        async (_stats: any, callback: any) => {
+          // we create entry -> module maps so that we can
+          // look them up faster instead of having to iterate
+          // over the compilation modules list
+          const entryNameMap = new Map<string, string>()
+          const entryModMap = new Map<string, any>()
+
+          try {
+            const depModMap = new Map<string, any>()
+
+            compilation.entries.forEach((entry) => {
+              const name = entry.name || entry.options?.name
+
+              if (name?.startsWith('pages/') && entry.dependencies[0]) {
+                const entryMod = getModuleFromDependency(
+                  compilation,
+                  entry.dependencies[0]
+                )
+
+                if (entryMod.resource) {
+                  entryNameMap.set(entryMod.resource, name)
+                  entryModMap.set(entryMod.resource, entryMod)
+                }
+              }
+            })
+
+            // TODO: investigate allowing non-sync fs calls in node-file-trace
+            // for better performance
+            const readFile = (path: string) => {
+              const mod = depModMap.get(path) || entryModMap.get(path)
+
+              // map the transpiled source when available to avoid
+              // parse errors in node-file-trace
+              const source = mod?.originalSource?.()
+
+              if (source) {
+                return source.buffer()
+              }
+
+              try {
+                return compilation.inputFileSystem.readFileSync(path)
+              } catch (e) {
+                if (e.code === 'ENOENT' || e.code === 'EISDIR') {
+                  return null
+                }
+                throw e
+              }
+            }
+            const readlink = (path: string) => {
+              try {
+                return compilation.inputFileSystem.readlinkSync(path)
+              } catch (e) {
+                if (
+                  e.code !== 'EINVAL' &&
+                  e.code !== 'ENOENT' &&
+                  e.code !== 'UNKNOWN'
+                ) {
+                  throw e
+                }
+                return null
+              }
+            }
+            const stat = (path: string) => {
+              try {
+                return compilation.inputFileSystem.statSync(path)
+              } catch (e) {
+                if (e.code === 'ENOENT') {
+                  return null
+                }
+                throw e
+              }
+            }
+
+            const nftCache = {}
+            const entryPaths = Array.from(entryModMap.keys())
+
+            for (const entry of entryPaths) {
+              depModMap.clear()
+              const entryMod = entryModMap.get(entry)
+              // TODO: investigate caching, will require ensuring no traced
+              // files in the cache have changed, we could potentially hash
+              // all traced files and only leverage the cache if the hashes
+              // match
+              // const cachedTraces = entryMod.buildInfo?.cachedNextEntryTrace
+
+              // Use cached trace if available and trace version matches
+              // if (
+              //   isWebpack5 &&
+              //   cachedTraces &&
+              //   cachedTraces.version === TRACE_OUTPUT_VERSION
+              // ) {
+              //   this.entryTraces.set(
+              //     entryNameMap.get(entry)!,
+              //     cachedTraces.tracedDeps
+              //   )
+              //   continue
+              // }
+              const collectDependencies = (mod: any) => {
+                if (!mod || !mod.dependencies) return
+
+                for (const dep of mod.dependencies) {
+                  const depMod = getModuleFromDependency(compilation, dep)
+
+                  if (depMod?.resource && !depModMap.get(depMod.resource)) {
+                    depModMap.set(depMod.resource, depMod)
+                    collectDependencies(depMod)
+                  }
+                }
+              }
+              collectDependencies(entryMod)
+
+              const toTrace: string[] = [entry, ...depModMap.keys()]
+
+              const root = nodePath.parse(process.cwd()).root
+              const result = await nodeFileTrace(toTrace, {
+                base: root,
+                cache: nftCache,
+                processCwd: this.appDir,
+                readFile,
+                readlink,
+                stat,
+                ignore: TRACE_IGNORES,
+              })
+
+              const tracedDeps: string[] = []
+
+              for (const file of result.fileList) {
+                if (result.reasons[file].type === 'initial') {
+                  continue
+                }
+                tracedDeps.push(nodePath.join(root, file))
+              }
+
+              // entryMod.buildInfo.cachedNextEntryTrace = {
+              //   version: TRACE_OUTPUT_VERSION,
+              //   tracedDeps,
+              // }
+              this.entryTraces.set(entryNameMap.get(entry)!, tracedDeps)
+            }
+
+            callback()
+          } catch (err) {
+            callback(err)
+          }
+        }
+      )
+    })
+  }
+}

packages/next/compiled/@vercel/nft/LICENSE

@@ -0,0 +1,7 @@
+Copyright 2019 Vercel, Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

packages/next/compiled/@vercel/nft/package.json

@@ -0,0 +1 @@
+{"name":"@vercel/nft","main":"index.js","license":"MIT"}