fix: correct bad propagation of exit signals (#7755)

packages/server/lib/util/node_options.ts

@@ -3,7 +3,7 @@ import debugModule from 'debug'
 
 const debug = debugModule('cypress:server:util:node_options')
 
-const NODE_OPTIONS = `--max-http-header-size=${1024 ** 2} --http-parser=legacy`
+export const NODE_OPTIONS = `--max-http-header-size=${1024 ** 2} --http-parser=legacy`
 
 /**
  * If Cypress was not launched via CLI, it may be missing certain startup
@@ -63,8 +63,9 @@ export function forkWithCorrectOptions (): void {
     { stdio: 'inherit' },
   )
   .on('error', () => {})
-  .on('exit', (code) => {
-    process.exit(code)
+  .on('exit', (code, signal) => {
+    debug('child exited %o', { code, signal })
+    process.exit(code === null ? 1 : code)
   })
 }
 

packages/server/test/scripts/run.js

@@ -164,4 +164,10 @@ console.log(cmd)
 
 const child = execa.shell(cmd, { env, stdio: 'inherit' })
 
-child.on('exit', process.exit)
+child.on('exit', (code, signal) => {
+  if (signal) {
+    console.error(`tests exited with signal ${signal}`)
+  }
+
+  process.exit(code === null ? 1 : code)
+})

packages/server/test/unit/node_options_spec.ts

@@ -0,0 +1,63 @@
+import '../spec_helper'
+import sinon from 'sinon'
+import { expect } from 'chai'
+import cp, { ChildProcess } from 'child_process'
+import { EventEmitter } from 'events'
+import * as nodeOptions from '../../lib/util/node_options'
+import mockedEnv from 'mocked-env'
+
+describe('NODE_OPTIONS lib', function () {
+  context('.forkWithCorrectOptions', function () {
+    let fakeProc: EventEmitter
+    let restoreEnv
+
+    beforeEach(() => {
+      restoreEnv = mockedEnv({
+        NODE_OPTIONS: '',
+        ORIGINAL_NODE_OPTIONS: '',
+      })
+    })
+
+    afterEach(() => {
+      restoreEnv()
+    })
+
+    it('modifies NODE_OPTIONS', function () {
+      process.env.NODE_OPTIONS = 'foo'
+      expect(process.env.NODE_OPTIONS).to.eq('foo')
+      sinon.stub(cp, 'spawn').callsFake(() => {
+        expect(process.env).to.include({
+          NODE_OPTIONS: `${nodeOptions.NODE_OPTIONS} foo`,
+          ORIGINAL_NODE_OPTIONS: 'foo',
+        })
+
+        return null as ChildProcess // types
+      })
+    })
+
+    context('when exiting', function () {
+      beforeEach(() => {
+        fakeProc = new EventEmitter()
+
+        sinon.stub(cp, 'spawn')
+        .withArgs(process.execPath, sinon.match.any, { stdio: 'inherit' })
+        .returns(fakeProc as ChildProcess)
+
+        sinon.stub(process, 'exit')
+      })
+
+      it('propagates exit codes correctly', function () {
+        nodeOptions.forkWithCorrectOptions()
+        fakeProc.emit('exit', 123)
+        expect(process.exit).to.be.calledWith(123)
+      })
+
+      // @see https://github.com/cypress-io/cypress/issues/7722
+      it('propagates signals via a non-zero exit code', function () {
+        nodeOptions.forkWithCorrectOptions()
+        fakeProc.emit('exit', null, 'SIGKILL')
+        expect(process.exit).to.be.calledWith(1)
+      })
+    })
+  })
+})