Fixed issue with parseLockFile not looking for dev dependencies

package.json

@@ -1,6 +1,6 @@
 {
   "name": "npm-diff",
-  "version": "1.0.0",
+  "version": "1.0.2",
   "description": "Generate a formatted diff of npm package-lock.json changes for pull requests",
   "main": "dist/index.js",
   "scripts": {

src/action.ts

@@ -7,8 +7,10 @@ interface PackageInfo {
 }
 
 interface LockfileData {
-  packages?: Record<string, PackageInfo>;
-  dependencies?: Record<string, PackageInfo>;
+  packages?: Record<string, PackageInfo | string>;
+  dependencies?: Record<string, PackageInfo | string>;
+  devDependencies?: Record<string, PackageInfo | string>;
+  optionalDependencies?: Record<string, PackageInfo | string>;
 }
 
 export interface PackageChange {
@@ -31,14 +33,33 @@ export function parseLockfile(
   try {
     const content = contentStr || fs.readFileSync(path, 'utf8');
     const data: LockfileData = JSON.parse(content);
-    const packages = data.packages || data.dependencies || {};
+    let packages: Record<string, PackageInfo | string> = {};
+
+    if (data.packages) {
+      packages = data.packages;
+    } else {
+      packages = {
+        ...(data.dependencies || {}),
+        ...(data.devDependencies || {}),
+        ...(data.optionalDependencies || {}),
+      };
+    }
 
     // Remove the root package entry if it exists to avoid comparing it
     if (packages['']) {
       delete packages[''];
     }
 
-    return packages;
+    const normalized: Record<string, PackageInfo> = {};
+    for (const [name, info] of Object.entries(packages)) {
+      if (typeof info === 'string') {
+        normalized[name] = { version: info };
+      } else if (info && typeof info === 'object') {
+        normalized[name] = info as PackageInfo;
+      }
+    }
+
+    return normalized;
   } catch {
     return {};
   }

test/action.test.js

@@ -1,7 +1,7 @@
 /* eslint-disable @typescript-eslint/no-require-imports, no-undef */
 const { test } = require('node:test');
 const assert = require('node:assert');
-const { comparePackages, formatMarkdown } = require('../src/action.ts');
+const { comparePackages, formatMarkdown, parseLockfile } = require('../src/action.ts');
 
 test('comparePackages identifies added, removed and updated packages', () => {
   const base = {
@@ -56,3 +56,43 @@ test('formatMarkdown formats changes as a table', () => {
   assert.match(markdown, /r \| Removed \| `1.0.0` \| - \|/);
   assert.match(markdown, /u \| Upgraded \| `1.0.0` \| `1.1.0` \|/);
 });
+
+test('parseLockfile handles package.json and devDependencies', () => {
+  const content = JSON.stringify({
+    dependencies: { 'prod-pkg': '1.0.0' },
+    devDependencies: { 'dev-pkg': '2.0.0' },
+    optionalDependencies: { 'opt-pkg': '3.0.0' },
+  });
+
+  const packages = parseLockfile('package.json', content);
+
+  assert.strictEqual(packages['prod-pkg'].version, '1.0.0');
+  assert.strictEqual(packages['dev-pkg'].version, '2.0.0');
+  assert.strictEqual(packages['opt-pkg'].version, '3.0.0');
+});
+
+test('parseLockfile handles lockfile v3 packages', () => {
+  const content = JSON.stringify({
+    packages: {
+      '': { name: 'root', version: '1.0.0' },
+      'node_modules/pkg': { version: '1.1.0' },
+    },
+  });
+
+  const packages = parseLockfile('package-lock.json', content);
+
+  assert.strictEqual(packages[''], undefined);
+  assert.strictEqual(packages['node_modules/pkg'].version, '1.1.0');
+});
+
+test('parseLockfile handles lockfile v1 dependencies', () => {
+  const content = JSON.stringify({
+    dependencies: {
+      pkg: { version: '1.1.0' },
+    },
+  });
+
+  const packages = parseLockfile('package-lock.json', content);
+
+  assert.strictEqual(packages['pkg'].version, '1.1.0');
+});