Turns out fs.execSync could throw and write to parent's stderr

markelog · Mar 12, 2016 · 84d4913 · 84d4913
1 parent e91314f
commit 84d4913
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Showing 2 changed files with 32 additions and 10 deletions.
diff --git a/index.js b/index.js
@@ -1,7 +1,6 @@
 import { execSync as exec } from 'child_process';
 
-function ip(type) {
-  type = type || 'default';
+function ip(type = 'default') {
   const isLinux = ip.platform === 'linux';
 
   if (!ip.present()) {
@@ -12,13 +11,24 @@ function ip(type) {
     return null;
   }
 
-  return ip.exec(`docker-machine ip ${type}`, { encoding: 'utf8' }).trim();
+  return ip.exec(`docker-machine ip ${type}`, {
+    encoding: 'utf8',
+
+    // By default parent stderr is used, which is bad
+    stdio: []
+  }).trim();
 }
 
 ip.present = () => {
-  const result = ip.exec('docker-machine version && echo $?', { encoding: 'utf8' }).trim();
 
-  if (result === '127') {
+  try {
+    ip.exec('docker-machine version && echo $?', {
+      encoding: 'utf8',
+
+      // By default parent stderr is used, which is bad
+      stdio: []
+    }).trim();
+  } catch (e) {
     return false;
   }
 

diff --git a/test/index.js b/test/index.js
@@ -16,7 +16,7 @@ describe('docker-ip', () => {
     });
 
     it('should return `false` for not "present" docker-machine', () => {
-      sinon.stub(ip, 'exec', () => '127');
+      sinon.stub(ip, 'exec', () => { throw new Error('test'); });
       expect(ip.present()).to.equal(false);
       ip.exec.restore();
     });
@@ -46,13 +46,19 @@ describe('docker-ip', () => {
       it('should get `default` ip without arguments', () => {
         ip();
         expect(ip.exec.firstCall.args[0]).to.equal('docker-machine ip default');
-        expect(ip.exec.firstCall.args[1]).to.deep.equal({ encoding: 'utf8' });
+        expect(ip.exec.firstCall.args[1]).to.deep.equal({
+          encoding: 'utf8',
+          stdio: []
+        });
       });
 
       it('should get `dev` ip', () => {
         ip('dev');
         expect(ip.exec.firstCall.args[0]).to.equal('docker-machine ip dev');
-        expect(ip.exec.firstCall.args[1]).to.deep.equal({ encoding: 'utf8' });
+        expect(ip.exec.firstCall.args[1]).to.deep.equal({
+          encoding: 'utf8',
+          stdio: []
+        });
       });
     });
 
@@ -101,13 +107,19 @@ describe('docker-ip', () => {
       it('should get `default` ip without arguments', () => {
         ip();
         expect(ip.exec.firstCall.args[0]).to.equal('docker-machine ip default');
-        expect(ip.exec.firstCall.args[1]).to.deep.equal({ encoding: 'utf8' });
+        expect(ip.exec.firstCall.args[1]).to.deep.equal({
+          encoding: 'utf8',
+          stdio: []
+        });
       });
 
       it('should get `dev` ip', () => {
         ip('dev');
         expect(ip.exec.firstCall.args[0]).to.equal('docker-machine ip dev');
-        expect(ip.exec.firstCall.args[1]).to.deep.equal({ encoding: 'utf8' });
+        expect(ip.exec.firstCall.args[1]).to.deep.equal({
+          encoding: 'utf8',
+          stdio: []
+        });
       });
     });