codeclimate: less memory allocation (#3882)

Author: lasiar

pkg/printers/codeclimate.go

@@ -2,7 +2,6 @@ package printers
 
 import (
 	"encoding/json"
-	"fmt"
 	"io"
 
 	"github.com/golangci/golangci-lint/pkg/result"
@@ -52,12 +51,7 @@ func (p CodeClimate) Print(issues []result.Issue) error {
 		codeClimateIssues = append(codeClimateIssues, codeClimateIssue)
 	}
 
-	outputJSON, err := json.Marshal(codeClimateIssues)
-	if err != nil {
-		return err
-	}
-
-	_, err = fmt.Fprint(p.w, string(outputJSON))
+	err := json.NewEncoder(p.w).Encode(codeClimateIssues)
 	if err != nil {
 		return err
 	}

pkg/printers/codeclimate_test.go

@@ -64,7 +64,8 @@ func TestCodeClimate_Print(t *testing.T) {
 	require.NoError(t, err)
 
 	//nolint:lll
-	expected := `[{"description":"linter-a: some issue","severity":"warning","fingerprint":"BA73C5DF4A6FD8462FFF1D3140235777","location":{"path":"path/to/filea.go","lines":{"begin":10}}},{"description":"linter-b: another issue","severity":"error","fingerprint":"0777B4FE60242BD8B2E9B7E92C4B9521","location":{"path":"path/to/fileb.go","lines":{"begin":300}}},{"description":"linter-c: issue c","severity":"critical","fingerprint":"BEE6E9FBB6BFA4B7DB9FB036697FB036","location":{"path":"path/to/filec.go","lines":{"begin":200}}}]`
+	expected := `[{"description":"linter-a: some issue","severity":"warning","fingerprint":"BA73C5DF4A6FD8462FFF1D3140235777","location":{"path":"path/to/filea.go","lines":{"begin":10}}},{"description":"linter-b: another issue","severity":"error","fingerprint":"0777B4FE60242BD8B2E9B7E92C4B9521","location":{"path":"path/to/fileb.go","lines":{"begin":300}}},{"description":"linter-c: issue c","severity":"critical","fingerprint":"BEE6E9FBB6BFA4B7DB9FB036697FB036","location":{"path":"path/to/filec.go","lines":{"begin":200}}}]
+`
 
 	assert.Equal(t, expected, buf.String())
 }