Use Output to exclusively read standard output from uglifyjs command

gopherjs · hajimehoshi · Apr 20, 2018 · Feb 27, 2018 · Apr 14, 2018 · Apr 15, 2018
commit 3de38f5a1cbc93f1aad88a5221735496df575b97
diff --git a/compiler/prelude/genmin.go b/compiler/prelude/genmin.go
@@ -3,6 +3,7 @@
 package main

 import (
+	"bytes"
 	"fmt"
 	"go/build"
 	"io/ioutil"
@@ -33,12 +34,15 @@ func run() error {
 		"--config-file",
 		filepath.Join(preludeDir, "uglifyjs_options.json"),
 	}
+
+	stderr := new(bytes.Buffer)
 	cmd := exec.Command(args[0], args[1:]...)
 	cmd.Stdin = strings.NewReader(prelude.Prelude)
+	cmd.Stderr = stderr

-	byts, err := cmd.CombinedOutput()
+	byts, err := cmd.Output()
 	if err != nil {
-		return fmt.Errorf("failed to run %v: %v\n%s", strings.Join(args, " "), err, string(byts))
+		return fmt.Errorf("failed to run %v: %v\n%s", strings.Join(args, " "), err, stderr.String())
 	}

 	fn := "prelude_min.go"
-Original file line number
+Diff line change
@@ -3,6 +3,7 @@
     package main
     import (
+    	"bytes"
     	"fmt"
     	"go/build"
     	"io/ioutil"
@@ -33,12 +34,15 @@ func run() error {
     		"--config-file",
     		filepath.Join(preludeDir, "uglifyjs_options.json"),
     	}
+    	stderr := new(bytes.Buffer)
     	cmd := exec.Command(args[0], args[1:]...)
     	cmd.Stdin = strings.NewReader(prelude.Prelude)
+    	cmd.Stderr = stderr
-    	byts, err := cmd.CombinedOutput()
+    	byts, err := cmd.Output()
             Copy link

  
      
    
  

  
      

  
  Member


      

  

  
    
      

      
            dmitshur
  

      

      

      


        Apr 19, 2018


      
    

  


        
      
  
  
  
    

    There was a problem hiding this comment.


  

 
  
    

    Choose a reason for hiding this comment

    
      The reason will be displayed to describe this comment to others. Learn more.
    

    
      
      


  


  
    
      This isn't a big deal, but it's pretty unusual to see a []byte variable named byts. As far as I understand, it's a shortened version of "bytes"? It comes up a total of 5 times in the Go project.
In this context, just b or out would be more idiomatic and clear I think.
I see that out is already taken below, in that case, I would make this variable name more specific. For example, minified.
The reason I point this out is because I think it's a good idea to strive to write Go code that looks like Go code other Go programmers are most likely to write.
    
  
  


    

        
      
  
  
    
  
  
  
    
    Sorry, something went wrong.
  

  
    
  
    
      

              Uh oh!

              
There was an error while loading. Please reload this page.


  
  


          
      
  
    
    
      
        
            
    All reactions
  


          
          
        
      
    

    



  
        
  
    
        
    
  


      
          
  
      
            Copy link

  
      
    
  

  
      

  
  Member


      

  Author


  

  
    
      

      
            myitcv
  

      

      

      


        Apr 20, 2018


      
    

  


        
      
  
  
  
    

    There was a problem hiding this comment.


  

 
  
    

    Choose a reason for hiding this comment

    
      The reason will be displayed to describe this comment to others. Learn more.
    

    
      
      


  


  
    
      Fixed.
    
  
  


    

        
      
  
  
    
  
  
  
    
    Sorry, something went wrong.
  

  
    
  
    
      

              Uh oh!

              
There was an error while loading. Please reload this page.


  
  


          
      
  
    
    
      
        
            
    All reactions
     	if err != nil {
-    		return fmt.Errorf("failed to run %v: %v\n%s", strings.Join(args, " "), err, string(byts))
+    		return fmt.Errorf("failed to run %v: %v\n%s", strings.Join(args, " "), err, stderr.String())
     	}
     	fn := "prelude_min.go"
-          Expand Down