Improve nilpointer error message

This commit is contained in:
Bjørn Erik Pedersen 2024-02-01 16:35:41 +01:00
parent 4174a7866b
commit 8d42a7942a
3 changed files with 35 additions and 1 deletions

View file

@ -19,8 +19,10 @@ import (
"fmt" "fmt"
"io" "io"
"os" "os"
"regexp"
"runtime" "runtime"
"runtime/debug" "runtime/debug"
"strings"
"time" "time"
) )
@ -116,3 +118,22 @@ func IsNotExist(err error) bool {
return false return false
} }
var nilPointerErrRe = regexp.MustCompile(`at <(.*)>: error calling (.*?): runtime error: invalid memory address or nil pointer dereference`)
func ImproveIfNilPointer(inErr error) (outErr error) {
outErr = inErr
m := nilPointerErrRe.FindStringSubmatch(inErr.Error())
if len(m) == 0 {
return
}
call := m[1]
field := m[2]
parts := strings.Split(call, ".")
receiverName := parts[len(parts)-2]
receiver := strings.Join(parts[:len(parts)-1], ".")
s := fmt.Sprintf(" %s is nil; wrap it in if or with: {{ with %s }}{{ .%s }}{{ end }}", receiverName, receiver, field)
outErr = errors.New(nilPointerErrRe.ReplaceAllString(inErr.Error(), s))
return
}

View file

@ -170,3 +170,15 @@ Paginator: {{ .Paginator }}
b.Assert(err, qt.IsNotNil) b.Assert(err, qt.IsNotNil)
b.Assert(err.Error(), qt.Contains, `error calling Paginator: pagination not supported for this page: kind: "page"`) b.Assert(err.Error(), qt.Contains, `error calling Paginator: pagination not supported for this page: kind: "page"`)
} }
func TestNilPointerErrorMessage(t *testing.T) {
files := `
-- hugo.toml --
-- content/p1.md --
-- layouts/_default/single.html --
Home Filename: {{ site.Home.File.Filename }}
`
b, err := TestE(t, files)
b.Assert(err, qt.IsNotNil)
b.Assert(err.Error(), qt.Contains, `_default/single.html:1:22: executing "_default/single.html" File is nil; wrap it in if or with: {{ with site.Home.File }}{{ .Filename }}{{ end }}`)
}

View file

@ -20,6 +20,7 @@ import (
"strings" "strings"
"sync" "sync"
"github.com/gohugoio/hugo/common/herrors"
"github.com/gohugoio/hugo/hugolib/doctree" "github.com/gohugoio/hugo/hugolib/doctree"
"github.com/gohugoio/hugo/config" "github.com/gohugoio/hugo/config"
@ -110,7 +111,7 @@ func (s *Site) renderPages(ctx *siteRenderContext) error {
err := <-errs err := <-errs
if err != nil { if err != nil {
return fmt.Errorf("failed to render pages: %w", err) return fmt.Errorf("failed to render pages: %w", herrors.ImproveIfNilPointer(err))
} }
return nil return nil
} }