From 9f4254c913d6883a0aac467bc000630807d7513a Mon Sep 17 00:00:00 2001
From: Henry Zhang <hzhang@freelancer.com>
Date: Fri, 19 Mar 2021 15:10:11 +1100
Subject: [PATCH] Support large stats.json files

---
 package-lock.json   |  5 ++++
 package.json        |  1 +
 src/analyzer.js     |  5 ++--
 src/bin/analyzer.js | 64 +++++++++++++++++++++++----------------------
 4 files changed, 41 insertions(+), 34 deletions(-)

diff --git a/package-lock.json b/package-lock.json
index f8464d13..e5ab4a2b 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1251,6 +1251,11 @@
       "integrity": "sha512-cDql5T3eS4Y5jzrDj25QNpU0pHgLFJ96MaoMAkJX8ceL2yat4u7EbIuqLoTbQLiTy1KxDRFbxHIKLzTUT64Duw==",
       "dev": true
     },
+    "@discoveryjs/json-ext": {
+      "version": "0.5.2",
+      "resolved": "https://registry.npmjs.org/@discoveryjs/json-ext/-/json-ext-0.5.2.tgz",
+      "integrity": "sha512-HyYEUDeIj5rRQU2Hk5HTB2uHsbRQpF70nvMhVzi+VJR0X+xNEhjPui4/kBf3VeH/wqD28PT4sVOm8qqLjBrSZg=="
+    },
     "@nodelib/fs.scandir": {
       "version": "2.1.3",
       "resolved": "https://registry.npmjs.org/@nodelib/fs.scandir/-/fs.scandir-2.1.3.tgz",
diff --git a/package.json b/package.json
index 60d099ba..9710e11e 100644
--- a/package.json
+++ b/package.json
@@ -33,6 +33,7 @@
     "src"
   ],
   "dependencies": {
+    "@discoveryjs/json-ext": "^0.5.2",
     "acorn": "^8.0.4",
     "acorn-walk": "^8.0.0",
     "chalk": "^4.1.0",
diff --git a/src/analyzer.js b/src/analyzer.js
index 5b76c258..e8cc170b 100644
--- a/src/analyzer.js
+++ b/src/analyzer.js
@@ -1,5 +1,6 @@
 const fs = require('fs');
 const path = require('path');
+const {parseChunked} = require('@discoveryjs/json-ext');
 
 const _ = require('lodash');
 const gzipSize = require('gzip-size');
@@ -162,9 +163,7 @@ function getViewerData(bundleStats, bundleDir, opts) {
 }
 
 function readStatsFromFile(filename) {
-  return JSON.parse(
-    fs.readFileSync(filename, 'utf8')
-  );
+  return parseChunked(fs.createReadStream(filename, {encoding: 'utf8'}));
 }
 
 function getChildAssetBundles(bundleStats, assetName) {
diff --git a/src/bin/analyzer.js b/src/bin/analyzer.js
index 5303578c..d4d2651c 100755
--- a/src/bin/analyzer.js
+++ b/src/bin/analyzer.js
@@ -110,44 +110,46 @@ bundleStatsFile = resolve(bundleStatsFile);
 
 if (!bundleDir) bundleDir = dirname(bundleStatsFile);
 
-let bundleStats;
+let bundleStatsPromise;
 try {
-  bundleStats = analyzer.readStatsFromFile(bundleStatsFile);
+  bundleStatsPromise = analyzer.readStatsFromFile(bundleStatsFile);
 } catch (err) {
   logger.error(`Couldn't read webpack bundle stats from "${bundleStatsFile}":\n${err}`);
   logger.debug(err.stack);
   process.exit(1);
 }
 
-if (mode === 'server') {
-  viewer.startServer(bundleStats, {
-    openBrowser,
-    port,
-    host,
-    defaultSizes,
-    reportTitle,
-    bundleDir,
-    excludeAssets,
-    logger: new Logger(logLevel)
-  });
-} else if (mode === 'static') {
-  viewer.generateReport(bundleStats, {
-    openBrowser,
-    reportFilename: resolve(reportFilename || 'report.html'),
-    reportTitle,
-    defaultSizes,
-    bundleDir,
-    excludeAssets,
-    logger: new Logger(logLevel)
-  });
-} else if (mode === 'json') {
-  viewer.generateJSONReport(bundleStats, {
-    reportFilename: resolve(reportFilename || 'report.json'),
-    bundleDir,
-    excludeAssets,
-    logger: new Logger(logLevel)
-  });
-}
+bundleStatsPromise.then(bundleStats => {
+  if (mode === 'server') {
+    viewer.startServer(bundleStats, {
+      openBrowser,
+      port,
+      host,
+      defaultSizes,
+      reportTitle,
+      bundleDir,
+      excludeAssets,
+      logger: new Logger(logLevel)
+    });
+  } else if (mode === 'static') {
+    viewer.generateReport(bundleStats, {
+      openBrowser,
+      reportFilename: resolve(reportFilename || 'report.html'),
+      reportTitle,
+      defaultSizes,
+      bundleDir,
+      excludeAssets,
+      logger: new Logger(logLevel)
+    });
+  } else if (mode === 'json') {
+    viewer.generateJSONReport(bundleStats, {
+      reportFilename: resolve(reportFilename || 'report.json'),
+      bundleDir,
+      excludeAssets,
+      logger: new Logger(logLevel)
+    });
+  }
+});
 
 function showHelp(error) {
   if (error) console.log(`\n  ${magenta(error)}\n`);