fix: workaround to fix the indexing of array of strings not working

The bug is in the jsonparser: buger/jsonparser#232

Signed-off-by: Leonardo Di Donato <leodidonato@gmail.com>

README.md

@@ -137,7 +137,7 @@ Like this:
 
 ```caddyfile
 log {
-  format jsonselect "{level} {timestamp:ts} {httpRequest>requestMethod:request>method} {httpRequest>protocol:request>proto} {httpRequest>status:status} {httpRequest>responseSize:size}" {
+  format jsonselect "{level} {timestamp:ts} {httpRequest>requestMethod:request>method} {httpRequest>protocol:request>proto} {httpRequest>status:status} {httpRequest>responseSize:size} {httpRequest>userAgent:request>headers>User-Agent>[0]}" {
     time_format "rfc3339_nano"
   }
 }
@@ -146,7 +146,7 @@ log {
 Which outputs:
 
 ```json
-{"level":"info","timestamp":"2021-07-19T14:48:56.262966Z","httpRequest":{"protocol":"HTTP/2.0","requestMethod":"GET","responseSize":17604,"status":200}}
+{"level":"info","timestamp":"2021-07-19T14:48:56.262966Z","httpRequest":{"protocol":"HTTP/2.0","requestMethod":"GET","responseSize":17604,"status":200,"userAgent":"Mozilla/5.0 ..."}}
 ```
 
 ## Try it out

plugin.go

@@ -109,25 +109,23 @@ func (e JSONSelectEncoder) EncodeEntry(entry zapcore.Entry, fields []zapcore.Fie
 		return buf, err
 	}
 
-	// fixme > indexing array of strings not working at the moment
-	// fixme > this is a bug in jsonparser (see https://github.com/buger/jsonparser/issues/232)
-	// todo > workaround by iterating on paths and calling jsonparser.Get()
 	res := []byte{'{', '}'}
-	jsonparser.EachKey(
-		buf.Bytes(),
-		func(idx int, val []byte, typ jsonparser.ValueType, err error) {
-			// todo > handle error
-			switch typ {
-			case jsonparser.NotExist:
-				// path not found, skip
-			case jsonparser.String:
-				res, _ = jsonparser.Set(res, append(append([]byte{'"'}, val...), '"'), e.setters[idx]...)
-			default:
-				res, _ = jsonparser.Set(res, val, e.setters[idx]...)
-			}
-		},
-		e.getters...,
-	)
+	// Temporary workaround the bug https://github.com/buger/jsonparser/issues/232
+	// todo > switch back to EachKey (see git history) for perf reasons when fixed
+	for idx, paths := range e.getters {
+		val, typ, _, err := jsonparser.Get(buf.Bytes(), paths...)
+		if err != nil {
+			return nil, err
+		}
+		switch typ {
+		case jsonparser.NotExist:
+			// path not found, skip
+		case jsonparser.String:
+			res, _ = jsonparser.Set(res, append(append([]byte{'"'}, val...), '"'), e.setters[idx]...)
+		default:
+			res, _ = jsonparser.Set(res, val, e.setters[idx]...)
+		}
+	}
 
 	// Reset the buffer to output our own content
 	buf.Reset()