cleanup: remove panic in testutil (#890)

* cleanup: remove panic in testutil

Signed-off-by: yxxhero <aiopsclub@163.com>

pkg/app/app_list_test.go

@@ -136,9 +136,10 @@ releases:
 			}
 
 			var listErr error
-			out := testutil.CaptureStdout(func() {
+			out, err := testutil.CaptureStdout(func() {
 				listErr = app.ListReleases(cfg)
 			})
+			assert.NoError(t, err)
 
 			var gotErr string
 			if listErr != nil {
@@ -277,10 +278,11 @@ releases:
 
 	expectNoCallsToHelm(app)
 
-	out := testutil.CaptureStdout(func() {
+	out, err := testutil.CaptureStdout(func() {
 		err := app.ListReleases(cfg)
 		assert.Nil(t, err)
 	})
+	assert.NoError(t, err)
 
 	expected := `[{"name":"myrelease1","namespace":"testNamespace","enabled":true,"installed":false,"labels":"id:myrelease1","chart":"mychart1","version":""},{"name":"myrelease2","namespace":"testNamespace","enabled":false,"installed":true,"labels":"","chart":"mychart1","version":""},{"name":"myrelease3","namespace":"testNamespace","enabled":true,"installed":true,"labels":"","chart":"mychart1","version":""},{"name":"myrelease4","namespace":"testNamespace","enabled":true,"installed":true,"labels":"id:myrelease1","chart":"mychart1","version":""}]
 `

pkg/app/app_test.go

@@ -4052,10 +4052,13 @@ releases:
 
 	expectNoCallsToHelm(app)
 
-	out := testutil.CaptureStdout(func() {
+	out, err := testutil.CaptureStdout(func() {
 		err := app.PrintState(configImpl{})
 		assert.Nil(t, err)
 	})
+
+	assert.NoError(t, err)
+
 	assert.True(t, strings.Count(out, "---") == 1,
 		"state should contain '---' yaml doc separator:\n%s\n", out)
 	assert.True(t, strings.Contains(out, "helmfile.yaml"),
@@ -4098,10 +4101,11 @@ releases:
 
 	expectNoCallsToHelm(app)
 
-	out := testutil.CaptureStdout(func() {
+	out, err := testutil.CaptureStdout(func() {
 		err := app.PrintState(configImpl{})
 		assert.Nil(t, err)
 	})
+	assert.NoError(t, err)
 	assert.True(t, strings.Count(out, "---") == 2,
 		"state should contain '---' yaml doc separators:\n%s\n", out)
 	assert.True(t, strings.Contains(out, "second.yaml"),
@@ -4158,10 +4162,11 @@ releases:
 
 	expectNoCallsToHelm(app)
 
-	out := testutil.CaptureStdout(func() {
+	out, err := testutil.CaptureStdout(func() {
 		err := app.ListReleases(configImpl{})
 		assert.Nil(t, err)
 	})
+	assert.NoError(t, err)
 
 	expected := `NAME      	NAMESPACE    	ENABLED	INSTALLED	LABELS                    	CHART   	VERSION
 myrelease1	testNamespace	true   	false    	common:label,id:myrelease1	mychart1	       

pkg/app/formatters_test.go

@@ -4,6 +4,8 @@ import (
 	"os"
 	"testing"
 
+	"github.com/stretchr/testify/assert"
+
 	"github.com/helmfile/helmfile/pkg/testutil"
 )
 
@@ -36,9 +38,12 @@ func TestFormatAsTable(t *testing.T) {
 		t.Errorf("error reading %s: %v", tableoutput, err)
 	}
 
-	result := testutil.CaptureStdout(func() {
+	result, err := testutil.CaptureStdout(func() {
 		FormatAsTable(h)
 	})
+
+	assert.NoError(t, err)
+
 	if result != string(expectd) {
 		t.Errorf("FormatAsTable() = %v, want %v", result, string(expectd))
 	}
@@ -70,10 +75,12 @@ func TestFormatAsJson(t *testing.T) {
 	if err != nil {
 		t.Errorf("error reading %s: %v", output, err)
 	}
-	result := testutil.CaptureStdout(func() {
+	result, err := testutil.CaptureStdout(func() {
 		FormatAsJson(h)
 	})
 
+	assert.NoError(t, err)
+
 	if result != string(expectd) {
 		t.Errorf("FormatAsJson() = %v, want %v", result, string(expectd))
 	}

pkg/testutil/testutil.go

@@ -9,10 +9,10 @@ import (
 )
 
 // CaptureStdout is a helper function to capture stdout.
-func CaptureStdout(f func()) string {
+func CaptureStdout(f func()) (string, error) {
 	reader, writer, err := os.Pipe()
 	if err != nil {
-		panic(err)
+		return "", err
 	}
 	stdout := os.Stdout
 	defer func() {
@@ -21,20 +21,21 @@ func CaptureStdout(f func()) string {
 	}()
 	os.Stdout = writer
 	log.SetOutput(writer)
-	out := make(chan string)
+	out := make(chan string, 1)
 	wg := new(sync.WaitGroup)
 	wg.Add(1)
+	var ioCopyErr error
 	go func() {
 		var buf bytes.Buffer
-		wg.Done()
-		_, err = io.Copy(&buf, reader)
-		if err != nil {
-			panic(err)
-		}
+		defer wg.Done()
+		_, ioCopyErr = io.Copy(&buf, reader)
 		out <- buf.String()
 	}()
-	wg.Wait()
 	f()
 	_ = writer.Close()
-	return <-out
+	wg.Wait()
+	if ioCopyErr != nil {
+		return "", ioCopyErr
+	}
+	return <-out, nil
 }

pkg/testutil/testutil_test.go

@@ -3,6 +3,8 @@ package testutil
 import (
 	"fmt"
 	"testing"
+
+	"github.com/stretchr/testify/assert"
 )
 
 // TestCaptureStdout tests the CaptureStdout function.
@@ -30,9 +32,10 @@ func TestCaptureStdout(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		result := CaptureStdout(func() {
+		result, err := CaptureStdout(func() {
 			fmt.Print(test.output)
 		})
+		assert.NoError(t, err)
 		if result != test.expected {
 			t.Errorf("CaptureStdout() = %v, want %v", result, test.expected)
 		}