wait the zombies (#1)

* wait the zombies

* close the reader

* defer order

* partially update tests

Author: dustin-decker

gitdiff/apply_test.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"io"
 	"io/ioutil"
+	"os/exec"
 	"path/filepath"
 	"testing"
 )
@@ -231,7 +232,9 @@ type applyTest struct {
 func (at applyTest) run(t *testing.T, apply func(io.Writer, *Applier, *File) error) {
 	src, patch, out := at.Files.Load(t)
 
-	files, _, err := Parse(bytes.NewReader(patch))
+	cmd := exec.Command("echo", "hello")
+
+	files, err := Parse(cmd, io.NopCloser(bytes.NewReader(patch)))
 	if err != nil {
 		t.Fatalf("failed to parse patch file: %v", err)
 	}

gitdiff/parser.go

@@ -7,6 +7,7 @@ import (
 	"bufio"
 	"fmt"
 	"io"
+	"os/exec"
 	"strings"
 )
 
@@ -15,7 +16,7 @@ const commitPrefix = "commit"
 // Parse parses a patch with changes to one or more files. Any content before
 // the first file is returned as the second value. If an error occurs while
 // parsing, it returns all files parsed before the error.
-func Parse(r io.Reader) (<-chan *File, error) {
+func Parse(cmd *exec.Cmd, r io.ReadCloser) (<-chan *File, error) {
 	p := newParser(r)
 	out := make(chan *File)
 
@@ -27,8 +28,10 @@ func Parse(r io.Reader) (<-chan *File, error) {
 		return out, err
 	}
 
-	go func() {
+	go func(cmd *exec.Cmd, out chan *File, r io.ReadCloser) {
 		defer close(out)
+		defer cmd.Wait()
+		defer r.Close()
 
 		ph := &PatchHeader{}
 		for {
@@ -65,7 +68,7 @@ func Parse(r io.Reader) (<-chan *File, error) {
 			file.PatchHeader = ph
 			out <- file
 		}
-	}()
+	}(cmd, out, r)
 
 	return out, nil
 }

gitdiff/parser_test.go

@@ -6,6 +6,7 @@ import (
 	"encoding/json"
 	"io"
 	"os"
+	"os/exec"
 	"reflect"
 	"testing"
 )
@@ -460,7 +461,9 @@ Date:   Tue Apr 2 22:55:40 2019 -0700
 				t.Fatalf("unexpected error opening input file: %v", err)
 			}
 
-			files, pre, err := Parse(f)
+			cmd := exec.Command("echo", "hello")
+
+			files, err := Parse(cmd, f)
 			if test.Err {
 				if err == nil || err == io.EOF {
 					t.Fatalf("expected error parsing patch, but got %v", err)
@@ -474,9 +477,6 @@ Date:   Tue Apr 2 22:55:40 2019 -0700
 			if len(test.Output) != len(files) {
 				t.Fatalf("incorrect number of parsed files: expected %d, actual %d", len(test.Output), len(files))
 			}
-			if test.Preamble != pre {
-				t.Errorf("incorrect preamble\nexpected: %q\n  actual: %q", test.Preamble, pre)
-			}
 			for i := range test.Output {
 				if !reflect.DeepEqual(test.Output[i], files[i]) {
 					exp, _ := json.MarshalIndent(test.Output[i], "", "  ")