Use JSONC for default server-external-packages

crates/next-core/src/next_font/google/font_fallback.rs

@@ -17,7 +17,7 @@ use crate::{
         issue::NextFontIssue,
         util::{FontFamilyType, get_scoped_font_family},
     },
-    util::load_next_js_templateon,
+    util::load_next_js_json_file,
 };
 
 /// An entry in the Google fonts metrics map
@@ -45,7 +45,7 @@ struct Fallback {
 // This JSON file is large, so we cache it in turbotasks
 #[turbo_tasks::function]
 async fn load_font_metrics(project_root: FileSystemPath) -> Result<Vc<FontMetricsMap>> {
-    let data: FontMetricsMap = load_next_js_templateon(
+    let data: FontMetricsMap = load_next_js_json_file(
         project_root,
         rcstr!("dist/server/capsize-font-metrics.json"),
     )

crates/next-core/src/next_font/google/mod.rs

@@ -52,7 +52,7 @@ use super::{
 };
 use crate::{
     embed_js::next_js_file_path, mode::NextMode, next_app::metadata::split_extension,
-    next_font::issue::NextFontIssue, util::load_next_js_templateon,
+    next_font::issue::NextFontIssue, util::load_next_js_json_file,
 };
 
 pub mod font_fallback;
@@ -466,7 +466,7 @@ impl ImportMappingReplacement for NextFontGoogleFontFileReplacer {
 
 #[turbo_tasks::function]
 async fn load_font_data(project_root: FileSystemPath) -> Result<Vc<FontData>> {
-    let data: FontData = load_next_js_templateon(
+    let data: FontData = load_next_js_json_file(
         project_root,
         rcstr!("dist/compiled/@next/font/dist/google/font-data.json"),
     )

crates/next-core/src/next_server/context.rs

@@ -73,7 +73,7 @@ use crate::{
     },
     util::{
         NextRuntime, OptionEnvMap, defines, foreign_code_context_condition,
-        get_transpiled_packages, internal_assets_conditions, load_next_js_templateon,
+        get_transpiled_packages, internal_assets_conditions, load_next_js_jsonc_file,
         module_styles_rule_condition,
     },
 };
@@ -162,9 +162,9 @@ pub async fn get_server_resolve_options_context(
             .await?;
 
     // Always load these predefined packages as external.
-    let mut external_packages: Vec<RcStr> = load_next_js_templateon(
+    let mut external_packages: Vec<RcStr> = load_next_js_jsonc_file(
         project_path.clone(),
-        rcstr!("dist/lib/server-external-packages.json"),
+        rcstr!("dist/lib/server-external-packages.jsonc"),
     )
     .await?;
 

crates/next-core/src/util.rs

@@ -1,13 +1,12 @@
 use std::{fmt::Display, str::FromStr};
 
-use anyhow::{Result, bail};
+use anyhow::{Result, anyhow, bail};
 use next_taskless::expand_next_js_template;
 use serde::{Deserialize, Serialize, de::DeserializeOwned};
 use turbo_rcstr::{RcStr, rcstr};
 use turbo_tasks::{FxIndexMap, NonLocalValue, TaskInput, Vc, trace::TraceRawVcs};
 use turbo_tasks_fs::{
-    self, File, FileContent, FileSystem, FileSystemPath, json::parse_json_rope_with_source_context,
-    rope::Rope,
+    self, File, FileContent, FileJsonContent, FileSystem, FileSystemPath, rope::Rope,
 };
 use turbopack::module_options::RuleCondition;
 use turbopack_core::{
@@ -118,7 +117,7 @@ pub async fn get_transpiled_packages(
 ) -> Result<Vc<Vec<RcStr>>> {
     let mut transpile_packages: Vec<RcStr> = next_config.transpile_packages().owned().await?;
 
-    let default_transpiled_packages: Vec<RcStr> = load_next_js_templateon(
+    let default_transpiled_packages: Vec<RcStr> = load_next_js_json_file(
         project_path,
         rcstr!("dist/lib/default-transpiled-packages.json"),
     )
@@ -288,24 +287,38 @@ async fn virtual_next_js_template_path(
         .join(&format!("{NEXT_TEMPLATE_PATH}/{file}"))
 }
 
-pub async fn load_next_js_templateon<T: DeserializeOwned>(
+pub async fn load_next_js_json_file<T: DeserializeOwned>(
     project_path: FileSystemPath,
-    path: RcStr,
+    sub_path: RcStr,
 ) -> Result<T> {
-    let file_path = get_next_package(project_path.clone()).await?.join(&path)?;
+    let file_path = get_next_package(project_path.clone())
+        .await?
+        .join(&sub_path)?;
 
     let content = &*file_path.read().await?;
 
-    let FileContent::Content(file) = content else {
-        bail!(
-            "Expected file content at {}",
-            file_path.value_to_string().await?
-        );
-    };
+    match content.parse_json_ref() {
+        FileJsonContent::Unparsable(e) => Err(anyhow!("File is not valid JSON: {}", e)),
+        FileJsonContent::NotFound => Err(anyhow!("File not found")),
+        FileJsonContent::Content(value) => Ok(serde_json::from_value(value)?),
+    }
+}
 
-    let result: T = parse_json_rope_with_source_context(file.content())?;
+pub async fn load_next_js_jsonc_file<T: DeserializeOwned>(
+    project_path: FileSystemPath,
+    sub_path: RcStr,
+) -> Result<T> {
+    let file_path = get_next_package(project_path.clone())
+        .await?
+        .join(&sub_path)?;
 
-    Ok(result)
+    let content = &*file_path.read().await?;
+
+    match content.parse_json_with_comments_ref() {
+        FileJsonContent::Unparsable(e) => Err(anyhow!("File is not valid JSON: {}", e)),
+        FileJsonContent::NotFound => Err(anyhow!("File not found")),
+        FileJsonContent::Content(value) => Ok(serde_json::from_value(value)?),
+    }
 }
 
 pub fn styles_rule_condition() -> RuleCondition {

docs/01-app/03-api-reference/05-config/01-next-config-js/serverExternalPackages.mdx

@@ -16,7 +16,7 @@ const nextConfig = {
 module.exports = nextConfig
 ```
 
-Next.js includes a [short list of popular packages](https://github.com/vercel/next.js/blob/canary/packages/next/src/lib/server-external-packages.json) that currently are working on compatibility and automatically opt-ed out:
+Next.js includes a [short list of popular packages](https://github.com/vercel/next.js/blob/canary/packages/next/src/lib/server-external-packages.jsonc) that currently are working on compatibility and automatically opt-ed out:
 
 - `@appsignal/nodejs`
 - `@aws-sdk/client-s3`

docs/02-pages/04-api-reference/04-config/01-next-config-js/serverExternalPackages.mdx

@@ -16,7 +16,7 @@ const nextConfig = {
 module.exports = nextConfig
 ```
 
-Next.js includes a [short list of popular packages](https://github.com/vercel/next.js/blob/canary/packages/next/src/lib/server-external-packages.json) that currently are working on compatibility and automatically opt-ed out:
+Next.js includes a [short list of popular packages](https://github.com/vercel/next.js/blob/canary/packages/next/src/lib/server-external-packages.jsonc) that currently are working on compatibility and automatically opt-ed out:
 
 - `@appsignal/nodejs`
 - `@aws-sdk/client-s3`

packages/next/src/build/webpack-config.ts

@@ -4,6 +4,7 @@ import { yellow, bold } from '../lib/picocolors'
 import crypto from 'crypto'
 import { webpack } from 'next/dist/compiled/webpack/webpack'
 import path from 'path'
+import fs from 'fs'
 
 import { getDefineEnv } from './define-env'
 import { escapeStringRegexp } from '../shared/lib/escape-regexp'
@@ -95,14 +96,19 @@ import type { NextBuildContext } from './build-context'
 import type { RootParamsLoaderOpts } from './webpack/loaders/next-root-params-loader'
 import type { InvalidImportLoaderOpts } from './webpack/loaders/next-invalid-import-error-loader'
 import { defaultOverrides } from '../server/require-hook'
+import JSON5 from 'next/dist/compiled/json5'
 
 type ExcludesFalse = <T>(x: T | false) => x is T
 type ClientEntries = {
   [key: string]: string | string[]
 }
 
-const EXTERNAL_PACKAGES =
-  require('../lib/server-external-packages.json') as string[]
+const EXTERNAL_PACKAGES = JSON5.parse(
+  fs.readFileSync(
+    path.join(__dirname, '../lib/server-external-packages.jsonc'),
+    'utf8'
+  )
+) as string[]
 
 const DEFAULT_TRANSPILED_PACKAGES =
   require('../lib/default-transpiled-packages.json') as string[]

packages/next/src/lib/server-external-packages.json → packages/next/src/lib/server-external-packages.jsonc

@@ -71,5 +71,5 @@
   "vscode-oniguruma",
   "webpack",
   "websocket",
-  "zeromq"
+  "zeromq",
 ]

packages/next/taskfile-swc.js

@@ -20,6 +20,7 @@ module.exports = function (task) {
       if (
         file.base.endsWith('.d.ts') ||
         file.base.endsWith('.json') ||
+        file.base.endsWith('.jsonc') ||
         file.base.endsWith('.woff2')
       )
         return

packages/next/taskfile.js

@@ -2415,14 +2415,14 @@ export async function cli(task, opts) {
 
 export async function lib(task, opts) {
   await task
-    .source('src/lib/**/!(*.test).+(js|ts|tsx|json)')
+    .source('src/lib/**/!(*.test).+(js|ts|tsx|json|jsonc)')
     .swc('server', { dev: opts.dev })
     .target('dist/lib')
 }
 
 export async function lib_esm(task, opts) {
   await task
-    .source('src/lib/**/!(*.test).+(js|ts|tsx|json)')
+    .source('src/lib/**/!(*.test).+(js|ts|tsx|json|jsonc)')
     .swc('server', { dev: opts.dev, esm: true })
     .target('dist/esm/lib')
 }

scripts/validate-externals-doc.js

@@ -1,7 +1,16 @@
 const fs = require('fs')
 const path = require('path')
+const JSON5 = require('next/dist/compiled/json5')
 
-const serverExternals = require('../packages/next/src/lib/server-external-packages.json')
+const serverExternals = JSON5.parse(
+  fs.readFileSync(
+    path.join(
+      __dirname,
+      '../packages/next/src/lib/server-external-packages.jsonc'
+    ),
+    'utf8'
+  )
+)
 
 function validate(docPath) {
   const docContent = fs.readFileSync(