Fix formatting when timestamp is unix timestamp and not string value

CHANGELOG.md

@@ -1,5 +1,7 @@
 ## Unreleased
 
+- [Fix] Fix formatting when `timestamp` is unix timestamp and not string value
+
 ## 0.3.0 (April 21th, 2021)
 
 - [Fix] Fix formatting when `caller` is not present

main.go

@@ -115,7 +115,7 @@ func (p *processor) process() {
 	}
 
 	if err := p.scanner.Err(); err != nil {
-		debugPrintln("Scanner terminated with error: %s", err)
+		debugPrintln("Scanner terminated with error: %w", err)
 	}
 }
 
@@ -203,7 +203,7 @@ func (p *processor) maybePrettyPrintLine(line string, lineData map[string]interf
 func (p *processor) maybePrettyPrintZapLine(line string, lineData map[string]interface{}) (string, error) {
 	logTimestamp, err := tsFieldToTimestamp(lineData["ts"])
 	if err != nil {
-		return "", fmt.Errorf("unable to process field 'ts': %s", err)
+		return "", fmt.Errorf("unable to process field 'ts': %w", err)
 	}
 
 	var caller *string
@@ -273,9 +273,10 @@ func (p *processor) maybePrettyPrintZapdriverLine(line string, lineData map[stri
 	}
 
 	var buffer bytes.Buffer
-	parsedTime, err := time.Parse(time.RFC3339, timeValue.(string))
+
+	parsedTime, err := tsFieldToTimestamp(timeValue)
 	if err != nil {
-		return "", fmt.Errorf("unable to process field 'time': %s", err)
+		return "", fmt.Errorf("unable to process field %q: %w", timeField, err)
 	}
 
 	var caller *string
@@ -290,7 +291,7 @@ func (p *processor) maybePrettyPrintZapdriverLine(line string, lineData map[stri
 		logger = &loggerStr
 	}
 
-	p.writeHeader(&buffer, &parsedTime, lineData["severity"].(string), caller, logger, lineData["message"].(string))
+	p.writeHeader(&buffer, parsedTime, lineData["severity"].(string), caller, logger, lineData["message"].(string))
 
 	// Delete standard stuff from data fields
 	delete(lineData, timeField)

main_test.go

@@ -111,6 +111,17 @@ func TestZapDriverNewProduction(t *testing.T) {
 				"[2018-12-21 23:06:49.435 EST] \x1b[32mINFO\x1b[0m \x1b[38;5;244m(c:0)\x1b[0m \x1b[34mm\x1b[0m {\"folder\":\"f\"}",
 			},
 		},
+
+		{
+			name: "line_with_timstamp_unix",
+			lines: []string{
+				`{"severity":"INFO","timestamp":"2022-06-16T23:11:09.929517378-04:00","message":"m","timestamp":1655435437,"logging.googleapis.com/labels":{}}`,
+			},
+			expectedLines: []string{
+				"[2022-06-16 23:10:37.000 EDT] \x1b[32mINFO\x1b[0m \x1b[34mm\x1b[0m",
+			},
+		},
+
 		{
 			name: "single_log_line_missing_fields",
 			lines: []string{