Fix: prevent TypeError when assets or modules are undefined in analyzer

CHANGELOG.md

@@ -12,6 +12,11 @@ _Note: Gaps between patch versions are faulty, broken or test releases._
 
 ## UNRELEASED
 
+* **Bug Fix**
+  * Prevent `TypeError` when `assets` or `modules` are undefined in `analyzer.js`
+    ([#679](https://github.com/webpack-contrib/webpack-bundle-analyzer/pull/679) by [@Srushti-33](https://github.com/Srushti-33))
+
+
 * **Breaking Change**
   * Remove explicit support for Node versions below 20.9.0 ([#676](https://github.com/webpack-contrib/webpack-bundle-analyzer/pull/676) by [@valscion](https://github.com/valscion))
 

src/analyzer.js

@@ -52,7 +52,7 @@ function getViewerData(bundleStats, bundleDir, opts) {
   }
 
   // Picking only `*.js, *.cjs or *.mjs` assets from bundle that has non-empty `chunks` array
-  bundleStats.assets = bundleStats.assets.filter(asset => {
+  bundleStats.assets = (bundleStats.assets || []).filter(asset => {
     // Filter out non 'asset' type asset if type is provided (Webpack 5 add a type to indicate asset types)
     if (asset.type && asset.type !== 'asset') {
       return false;
@@ -116,7 +116,7 @@ function getViewerData(bundleStats, bundleDir, opts) {
     }
 
     // Picking modules from current bundle script
-    let assetModules = modules.filter(statModule => assetHasModule(statAsset, statModule));
+    let assetModules = (modules || []).filter(statModule => assetHasModule(statAsset, statModule));
 
     // Adding parsed sources
     if (parsedModules) {
@@ -140,7 +140,7 @@ function getViewerData(bundleStats, bundleDir, opts) {
           unparsedEntryModules[0].parsedSrc = assetSources.runtimeSrc;
         } else {
           // If there are multiple entry points we move all of them under synthetic concatenated module.
-          assetModules = assetModules.filter(mod => !unparsedEntryModules.includes(mod));
+          assetModules = (assetModules || []).filter(mod => !unparsedEntryModules.includes(mod));
           assetModules.unshift({
             identifier: './entry modules',
             name: './entry modules',

test/real-world-stats.test.js

@@ -0,0 +1,55 @@
+const {expect} = require('chai');
+const analyzer = require('../lib/analyzer');
+
+describe('Real-world incomplete stats scenarios', function() {
+  it('should handle stats from minimal webpack config', function() {
+    const realWorldStats = {
+      version: "5.0.0",
+      hash: "abc123def456",
+      publicPath: "/dist/",
+      outputPath: "/project/dist",
+      chunks: [
+        {
+          id: 0,
+          names: ["main"],
+          files: ["main.js"],
+          hash: "abc123",
+          size: 1024
+        }
+      ],
+      // Real-world scenario: assets array missing (common in minimal configs)
+      // Real-world scenario: modules array missing (some webpack versions)
+      errors: [],
+      warnings: [],
+      entrypoints: {
+        main: {
+          chunks: [0],
+          assets: ["main.js"]
+        }
+      }
+    };
+
+    expect(() => {
+      const result = analyzer.getViewerData(realWorldStats);
+      expect(result).to.be.an('array');
+    }).not.to.throw();
+  });
+
+  it('should handle stats with only essential webpack 5 fields', function() {
+    const webpack5MinimalStats = {
+      version: "5.0.0",
+      hash: "webpack5minimal",
+      publicPath: "/",
+      outputPath: "/build",
+      chunks: [],
+      entrypoints: {},
+      // Common real-world scenario: missing assets and modules
+      errors: [],
+      warnings: [],
+      namedChunkGroups: {}
+    };
+
+    const result = analyzer.getViewerData(webpack5MinimalStats);
+    expect(result).to.be.an('array').that.is.empty;
+  });
+});