Make ToString() return an error instead of panic (#117)
Fixes #100
diff --git a/parser_test.go b/parser_test.go
index 048f514..188876b 100644
--- a/parser_test.go
+++ b/parser_test.go
@@ -673,7 +673,10 @@
t.Errorf("Test failed to parse: %v", err)
return
}
- result := tree.ToString()
+ result, err := tree.ToString()
+ if err != nil {
+ t.Errorf("Unexpected error: %s", err)
+ }
expected := "\n[foo]\n\n [[foo.bar]]\n a = 42\n\n [[foo.bar]]\n a = 69\n"
if result != expected {
t.Errorf("Expected got '%s', expected '%s'", result, expected)
diff --git a/tomltree_conversions.go b/tomltree_conversions.go
index db3da0d..fc8f22b 100644
--- a/tomltree_conversions.go
+++ b/tomltree_conversions.go
@@ -87,7 +87,7 @@
case nil:
return ""
default:
- panic(fmt.Sprintf("unsupported value type %T: %v", value, value))
+ panic(fmt.Errorf("unsupported value type %T: %v", value, value))
}
}
@@ -154,6 +154,23 @@
return strings.Join(resultChunks, "")
}
+// Same as ToToml(), but does not panic and returns an error
+func (t *TomlTree) toTomlSafe(indent, keyspace string) (result string, err error) {
+ defer func() {
+ if r := recover(); r != nil {
+ result = ""
+ switch x := r.(type) {
+ case error:
+ err = x
+ default:
+ err = fmt.Errorf("unknown panic: %s", r)
+ }
+ }
+ }()
+ result = t.toToml(indent, keyspace)
+ return
+}
+
func convertMapStringString(in map[string]string) map[string]interface{} {
result := make(map[string]interface{}, len(in))
for k, v := range in {
@@ -170,15 +187,18 @@
return result
}
-// ToString is an alias for String
-func (t *TomlTree) ToString() string {
- return t.String()
+// ToString generates a human-readable representation of the current tree.
+// Output spans multiple lines, and is suitable for ingest by a TOML parser.
+// If the conversion cannot be performed, ToString returns a non-nil error.
+func (t *TomlTree) ToString() (string, error) {
+ return t.toTomlSafe("", "")
}
// String generates a human-readable representation of the current tree.
-// Output spans multiple lines, and is suitable for ingest by a TOML parser
+// Alias of ToString.
func (t *TomlTree) String() string {
- return t.toToml("", "")
+ result, _ := t.ToString()
+ return result
}
// ToMap recursively generates a representation of the current tree using map[string]interface{}.
diff --git a/tomltree_conversions_test.go b/tomltree_conversions_test.go
index af3e9df..40b29b7 100644
--- a/tomltree_conversions_test.go
+++ b/tomltree_conversions_test.go
@@ -1,6 +1,7 @@
package toml
import (
+ "errors"
"reflect"
"strings"
"testing"
@@ -15,7 +16,8 @@
t.Fatal("Unexpected error:", err)
}
- reparsedTree, err := Load(toml.ToString())
+ tomlString, _ := toml.ToString()
+ reparsedTree, err := Load(tomlString)
assertTree(t, reparsedTree, err, map[string]interface{}{
"name": map[string]interface{}{
@@ -39,7 +41,7 @@
foo = 1
bar = "baz2"`)
- stringRepr := tree.ToString()
+ stringRepr, _ := tree.ToString()
t.Log("Intermediate string representation:")
t.Log(stringRepr)
@@ -69,6 +71,19 @@
}
}
+func TestToStringTypeConversionError(t *testing.T) {
+ tree := TomlTree{
+ values: map[string]interface{}{
+ "thing": []string{"unsupported"},
+ },
+ }
+ _, err := tree.ToString()
+ expected := errors.New("unsupported value type []string: [unsupported]")
+ if err.Error() != expected.Error() {
+ t.Errorf("expecting error %s, but got %s instead", expected, err)
+ }
+}
+
func TestTomlTreeConversionToMapSimple(t *testing.T) {
tree, _ := Load("a = 42\nb = 17")
