simonepri · simonepri · Jun 8, 2026 · Jun 8, 2026
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
@@ -9,19 +9,14 @@ on:
 jobs:
   lint:
     runs-on: ubuntu-latest
-    name: XO & Prettier
     steps:
       - name: Setup repo
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
       - name: Setup node
         uses: actions/setup-node@v4
         with:
-          # Pinned: the legacy xo@0.20 toolchain crashes on modern Node
-          # (util.isDate was removed). Revisit when the toolchain is updated.
-          node-version: 14
-      - name: Install dev dependencies
-        run: |
-          npm install --only=dev
-          npm list --dev --depth=0
+          node-version: 22
+      - name: Install dependencies
+        run: npm install
       - name: Run lint
         run: npm run lint
diff --git a/.github/workflows/test-macos.yml b/.github/workflows/test-macos.yml
@@ -9,32 +9,20 @@ on:
 jobs:
   test:
     runs-on: macos-latest
-    name: AVA & TSD & Benchmark & Codecov
     strategy:
       fail-fast: false
+      # Node 26+ is not yet supported by the coverage tool (c8); revisit
+      # "current" once the toolchain catches up.
       matrix:
-        node: [current, 22, 20, 18]
+        node: [24, 22, 20, 18]
     steps:
       - name: Setup repo
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Setup node ${{ matrix.node }}
-        uses: actions/setup-node@v3
+        uses: actions/setup-node@v4
         with:
           node-version: ${{ matrix.node }}
-      - name: Install lib dependencies
-        run: |
-          npm install --only=prod
-          npm list --prod --depth=0
-      - name: Install dev dependencies
-        run: |
-          npm install --only=dev
-          npm list --dev --depth=0
+      - name: Install dependencies
+        run: npm install
       - name: Run tests
-        run: npm run test
-      #- name: Run type checking
-      #  run: npm run types
-      - name: Run benchmark
-        run: |
-          npm run bench
-      - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@v2
+        run: npm test
diff --git a/.github/workflows/test-ubuntu.yml b/.github/workflows/test-ubuntu.yml
@@ -9,32 +9,26 @@ on:
 jobs:
   test:
     runs-on: ubuntu-latest
-    name: AVA & TSD & Benchmark & Codecov
     strategy:
       fail-fast: false
+      # Node 26+ is not yet supported by the coverage tool (c8); revisit
+      # "current" once the toolchain catches up.
       matrix:
-        node: [current, 22, 20, 18]
+        node: [24, 22, 20, 18]
     steps:
       - name: Setup repo
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Setup node ${{ matrix.node }}
-        uses: actions/setup-node@v3
+        uses: actions/setup-node@v4
         with:
           node-version: ${{ matrix.node }}
-      - name: Install lib dependencies
-        run: |
-          npm install --only=prod
-          npm list --prod --depth=0
-      - name: Install dev dependencies
-        run: |
-          npm install --only=dev
-          npm list --dev --depth=0
+      - name: Install dependencies
+        run: npm install
       - name: Run tests
-        run: npm run test
-      #- name: Run type checking
-      #  run: npm run types
+        run: npm test
+      - name: Run type checking
+        run: npm run types
       - name: Run benchmark
-        run: |
-          npm run bench
+        run: npm run bench
       - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@v2
+        uses: codecov/codecov-action@v5
diff --git a/.github/workflows/test-windows.yml b/.github/workflows/test-windows.yml
@@ -11,37 +11,20 @@ jobs:
     # windows-latest is Windows Server 2025, which ships without wmic, so the
     # integration tests here run against the PowerShell fallback in lib/get.js.
     runs-on: windows-latest
-    name: AVA & TSD & Benchmark & Codecov
     strategy:
       fail-fast: false
+      # Node 26+ is not yet supported by the coverage tool (c8); revisit
+      # "current" once the toolchain catches up.
       matrix:
-        node: [current, 22, 20, 18]
+        node: [24, 22, 20, 18]
     steps:
       - name: Setup repo
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Setup node ${{ matrix.node }}
-        uses: actions/setup-node@v3
+        uses: actions/setup-node@v4
         with:
           node-version: ${{ matrix.node }}
-      - name: Install lib dependencies
-        run: |
-          npm install --only=prod
-          npm list --prod --depth=0
-      - name: Install dev dependencies
-        run: |
-          npm install --only=dev
-          npm list --dev --depth=0
+      - name: Install dependencies
+        run: npm install
       - name: Run tests
-        if: ${{ matrix.node <= 6 }}
-        run: npm run test
-      - name: Run tests
-        if: ${{ !(matrix.node <= 6) }}
-        run: npm run test:windows
-      #- name: Run type checking
-      #  run: npm run types
-      - name: Run benchmark
-        run: |
-          npm run bench
-      - name: Upload coverage to Codecov
-        if: ${{ matrix.node <= 6 }}
-        uses: codecov/codecov-action@v2
+        run: npm test
diff --git a/bin/pidtree.js b/bin/pidtree.js
@@ -1,36 +1,28 @@
 #!/usr/bin/env node
 
-'use strict';
-
-var os = require('os');
-var pidtree = require('..');
-
-// The method startsWith is not defined on string objects in node 0.10
-// eslint-disable-next-line no-extend-native
-String.prototype.startsWith = function(suffix) {
-  return this.substring(0, suffix.length) === suffix;
-};
+import os from 'node:os';
+import pidtree from '../index.js';
 
 function help() {
-  var help =
+  console.log(
     '  Usage\n' +
-    '  $ pidtree <ppid>\n' +
-    '\n' +
-    'Options\n' +
-    '  --list                     To print the pids as a list.\n' +
-    '\n' +
-    'Examples\n' +
-    '  $ pidtree\n' +
-    '  $ pidtree --list\n' +
-    '  $ pidtree 1\n' +
-    '  $ pidtree 1 --list\n';
-  console.log(help);
+      '  $ pidtree <ppid>\n' +
+      '\n' +
+      'Options\n' +
+      '  --list                     To print the pids as a list.\n' +
+      '\n' +
+      'Examples\n' +
+      '  $ pidtree\n' +
+      '  $ pidtree --list\n' +
+      '  $ pidtree 1\n' +
+      '  $ pidtree 1 --list\n',
+  );
 }
 
 function list(ppid) {
-  pidtree(ppid === undefined ? -1 : ppid, function(err, list) {
-    if (err) {
-      console.error(err.message);
+  pidtree(ppid === undefined ? -1 : ppid, (error, list) => {
+    if (error) {
+      console.error(error.message);
       return;
     }
 
@@ -39,16 +31,16 @@ function list(ppid) {
 }
 
 function tree(ppid) {
-  pidtree(ppid, {advanced: true}, function(err, list) {
-    if (err) {
-      console.error(err.message);
+  pidtree(ppid, {advanced: true}, (error, list) => {
+    if (error) {
+      console.error(error.message);
       return;
     }
 
-    var parents = {}; // Hash Map of parents
-    var tree = {}; // Adiacency Hash Map
+    const parents = {}; // Hash Map of parents
+    const tree = {}; // Adjacency Hash Map
     while (list.length > 0) {
-      var element = list.pop();
+      const element = list.pop();
       if (tree[element.ppid]) {
         tree[element.ppid].push(element.pid);
       } else {
@@ -60,55 +52,53 @@ function tree(ppid) {
       }
     }
 
-    var roots = [ppid];
+    let roots = [ppid];
     if (ppid === -1) {
-      // Get all the roots
-      roots = Object.keys(tree).filter(function(node) {
-        return parents[node] === undefined;
-      });
+      // Get all the roots.
+      roots = Object.keys(tree).filter((node) => parents[node] === undefined);
     }
 
-    roots.forEach(function(root) {
+    for (const root of roots) {
       print(tree, root);
-    });
+    }
   });
 
   function print(tree, start) {
     function printBranch(node, branch) {
-      var isGraphHead = branch.length === 0;
-      var children = tree[node] || [];
+      const isGraphHead = branch.length === 0;
+      const children = tree[node] || [];
 
-      var branchHead = '';
+      let branchHead = '';
       if (!isGraphHead) {
         branchHead = children.length > 0 ? '┬ ' : '─ ';
       }
 
       console.log(branch + branchHead + node);
 
-      var baseBranch = branch;
+      let baseBranch = branch;
       if (!isGraphHead) {
-        var isChildOfLastBranch = branch.slice(-2) === '└─';
+        const isChildOfLastBranch = branch.slice(-2) === '└─';
         baseBranch = branch.slice(0, -2) + (isChildOfLastBranch ? '  ' : '| ');
       }
 
-      var nextBranch = baseBranch + '├─';
-      var lastBranch = baseBranch + '└─';
-      children.forEach(function(child, index) {
+      const nextBranch = baseBranch + '├─';
+      const lastBranch = baseBranch + '└─';
+      for (const [index, child] of children.entries()) {
         printBranch(
           child,
-          children.length - 1 === index ? lastBranch : nextBranch
+          children.length - 1 === index ? lastBranch : nextBranch,
         );
-      });
+      }
     }
 
     printBranch(start, '');
   }
 }
 
 function run() {
-  var flag;
-  var ppid;
-  for (var i = 2; i < process.argv.length; i++) {
+  let flag;
+  let ppid;
+  for (let i = 2; i < process.argv.length; i++) {
     if (process.argv[i].startsWith('--')) {
       flag = process.argv[i];
     } else {
@@ -120,9 +110,13 @@ function run() {
     ppid = -1;
   }
 
-  if (flag === '--list') list(ppid);
-  else if (flag === undefined) tree(ppid);
-  else help();
+  if (flag === '--list') {
+    list(ppid);
+  } else if (flag === undefined) {
+    tree(ppid);
+  } else {
+    help();
+  }
 }
 
 run();