Add v16.7.2

encoding/json/json.go

@@ -0,0 +1,60 @@
+// Package json implements
+package json
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+// Unmarshal is a wrapper for json.Unmarshal
+func Unmarshal(data []byte, v interface{}) error {
+	return json.Unmarshal(data, v)
+}
+
+// FormatError takes the marshalled data and the error from Unmarshal and returns a detailed
+// error message where the error was and what the error is.
+func FormatError(input []byte, err error) error {
+	if jsonError, ok := err.(*json.SyntaxError); ok {
+		line, character, offsetError := lineAndCharacter(input, int(jsonError.Offset))
+		if offsetError != nil {
+			return err
+		}
+
+		return fmt.Errorf("syntax error at line %d, character %d: %w", line, character, err)
+	}
+
+	if jsonError, ok := err.(*json.UnmarshalTypeError); ok {
+		line, character, offsetError := lineAndCharacter(input, int(jsonError.Offset))
+		if offsetError != nil {
+			return err
+		}
+
+		return fmt.Errorf("expect type '%s' for '%s' at line %d, character %d: %w", jsonError.Type.String(), jsonError.Field, line, character, err)
+	}
+
+	return err
+}
+
+func lineAndCharacter(input []byte, offset int) (line int, character int, err error) {
+	lf := byte(0x0A)
+
+	if offset > len(input) || offset < 0 {
+		return 0, 0, fmt.Errorf("couldn't find offset %d within the input", offset)
+	}
+
+	// Humans tend to count from 1.
+	line = 1
+
+	for i, b := range input {
+		if b == lf {
+			line++
+			character = 0
+		}
+		character++
+		if i == offset {
+			break
+		}
+	}
+
+	return line, character, nil
+}