Merge pull request #4 from morikuni/error-formatter

Implement failure.ErrorFormatter

.github/workflows/test.yml

@@ -10,6 +10,9 @@ jobs:
   test:
     name: test
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      pull-requests: write
     steps:
       - uses: actions/checkout@v3
       - uses: reviewdog/action-golangci-lint@v2

README.md

@@ -50,7 +50,7 @@ func IHavePen(count int) mlang.Message {
 	}
 }
 
-func ExampleSet() {
+func main() {
 	fmt.Println(InvalidUserName.MustGet(language.English))
 	// Invalid user name
 	fmt.Println(InvalidUserName.MustGet(language.Japanese))

example_test.go

@@ -41,7 +41,7 @@ func IHavePen(count int) mlang.Message {
 	}
 }
 
-func ExampleSet() {
+func ExampleDict() {
 	fmt.Println(InvalidUserName.MustGet(language.English))
 	fmt.Println(InvalidUserName.MustGet(language.Japanese))
 

go.mod

@@ -4,4 +4,4 @@ go 1.20
 
 require golang.org/x/text v0.9.0
 
-require github.com/morikuni/failure/v2 v2.0.0-20230512003104-6bb497ead261 // indirect
+require github.com/morikuni/failure/v2 v2.0.0-20230512003104-6bb497ead261

mlang.go

@@ -2,6 +2,7 @@ package mlang
 
 import (
 	"fmt"
+	"io"
 
 	"github.com/morikuni/failure/v2"
 
@@ -51,6 +52,13 @@ func (d Dict[M]) SetErrorField(field failure.FieldSetter) {
 	field.Set(internal.FailureKey, Message(d))
 }
 
+var _ failure.ErrorFormatter = Dict[string]{}
+
+// FormatError implements failure.ErrorFormatter.
+func (d Dict[M]) FormatError(w io.Writer) {
+	_, _ = io.WriteString(w, d.MustGet(-1)) // put -1 as a dummy language. Randomly picked language is used.
+}
+
 func eval(msg any, lang Language) (string, bool) {
 	switch m := msg.(type) {
 	case Template: