fix(npm-lifecycle): properly handle SIGINT from child process (#41)

When a child process sends the INT signal, pnpm should not assume child failed to terminate

Closes pnpm/pnpm#7164

Co-authored-by: Yanick Rochon <yanick.rochon@dynamicly.com>

index.js

@@ -278,7 +278,7 @@ function runCmd_ (cmd, pkg, env, wd, opts, stage, unsafe, uid, gid, cb_) {
   proc.on('close', (code, signal) => {
     opts.log.silly('lifecycle', logid(pkg, stage), 'Returned: code:', code, ' signal:', signal)
     let err
-    if (signal) {
+    if (signal && signal !== "SIGINT") {
       err = new PnpmError('CHILD_PROCESS_FAILED', `Command failed with signal "${signal}"`)
       process.kill(process.pid, signal)
     } else if (code) {
@@ -304,7 +304,7 @@ function runCmd_ (cmd, pkg, env, wd, opts, stage, unsafe, uid, gid, cb_) {
       if (er.code !== 'EPERM') {
         er.code = 'ELIFECYCLE'
       }
-      fs.stat(opts.dir, (statError, d) => {
+      fs.stat(opts.dir, (statError) => {
         if (statError && statError.code === 'ENOENT' && opts.dir.split(path.sep).slice(-1)[0] === 'node_modules') {
           opts.log.warn('', 'Local package.json exists, but node_modules missing, did you mean to install?')
         }

test/fixtures/count-to-10/package.json

@@ -3,6 +3,7 @@
   "version": "1.0.0",
   "scripts": {
     "postinstall": "node postinstall",
-    "signal-exit": "echo 'signal-exit script' && kill -s ABRT $$"
+    "signal-abrt": "echo 'signal-exit script' && kill -s ABRT $$",
+    "signal-int": "echo 'signal-int script' && kill -s INT $$"
   }
 }

test/index.js

@@ -183,13 +183,72 @@ test('throw error signal kills child', async function (t) {
   const dir = fixture
   const pkg = require(path.join(fixture, 'package.json'))
 
-  t.rejects(async () => {
-    await lifecycle(pkg, 'signal-exit', fixture, {
+  await t.rejects(async () => {
+    await lifecycle(pkg, 'signal-abrt', fixture, {
       stdio: 'pipe',
       log,
       dir,
       config: {}
     })
-    stubProcessExit.restore()
   })
+
+  stubProcessExit.restore()
+})
+
+test('no error on INT signal from child', async function (t) {
+  const fixture = path.join(__dirname, 'fixtures', 'count-to-10')
+
+  const verbose = sinon.spy()
+  const silly = sinon.spy()
+  const info = sinon.spy()
+
+  const stubProcessExit = sinon.stub(process, 'kill').callsFake(noop)
+
+  const log = {
+    level: 'silent',
+    info,
+    warn: noop,
+    silly,
+    verbose,
+    pause: noop,
+    resume: noop,
+    clearProgress: noop,
+    showProgress: noop
+  }
+
+  const dir = fixture
+  const pkg = require(path.join(fixture, 'package.json'))
+
+  await t.resolves(async () => {
+    await lifecycle(pkg, 'signal-int', fixture, {
+      stdio: 'pipe',
+      log,
+      dir,
+      config: {}
+    })
+  })
+
+  stubProcessExit.restore()
+
+  t.ok(
+    !info.calledWithMatch(
+      'lifecycle',
+      'undefined~signal-int:',
+      'Failed to exec signal-int script'
+    ),
+    'INT signal intercepted incorrectly'
+  )
+
+  t.ok(
+    silly.calledWithMatch(
+      'lifecycle',
+      'undefined~signal-int:',
+      'Returned: code:',
+      null,
+      ' signal:',
+      'SIGINT'
+    ),
+    'INT signal reported'
+  )
+
 })