catch EPIPE errors (#2011)

fixes #1841

cli/test/lib/exec/spawn_spec.js

@@ -4,6 +4,7 @@ const cp = require('child_process')
 const os = require('os')
 const tty = require('tty')
 const path = require('path')
+const EE = require('events')
 
 const state = require(`${lib}/tasks/state`)
 const xvfb = require(`${lib}/exec/xvfb`)
@@ -35,6 +36,7 @@ describe('lib/exec/spawn', function () {
         on: sinon.stub().returns(undefined),
       },
     }
+    sinon.stub(process, 'stdin').value(new EE)
     sinon.stub(cp, 'spawn').returns(this.spawnedProcess)
     sinon.stub(xvfb, 'start').resolves()
     sinon.stub(xvfb, 'stop').resolves()
@@ -313,5 +315,39 @@ describe('lib/exec/spawn', function () {
         expect(process.stderr.write).not.to.be.calledWith(buf1)
       })
     })
+
+    it('catches process.stdin errors and returns when code=EPIPE', function () {
+      this.spawnedProcess.on.withArgs('close').yieldsAsync(0)
+
+      return spawn.start()
+      .then(() => {
+        let called = false
+
+        const fn = () => {
+          called = true
+          const err = new Error()
+          err.code = 'EPIPE'
+          return process.stdin.emit('error', err)
+        }
+
+        expect(fn).not.to.throw()
+        expect(called).to.be.true
+      })
+    })
+
+    it('throws process.stdin errors code!=EPIPE', function () {
+      this.spawnedProcess.on.withArgs('close').yieldsAsync(0)
+
+      return spawn.start()
+      .then(() => {
+        const fn = () => {
+          const err = new Error('wattttt')
+          err.code = 'FAILWHALE'
+          return process.stdin.emit('error', err)
+        }
+
+        expect(fn).to.throw(/wattttt/)
+      })
+    })
   })
 })