Auto output format (#1599)

* Use file extension to auto detect output format!

* Use file extension to auto detect output format!

* formatting

pkg/yqlib/decoder.go

@@ -39,21 +39,22 @@ func InputFormatFromString(format string) (InputFormat, error) {
 	case "tsv", "t":
 		return TSVObjectInputFormat, nil
 	default:
-		return 0, fmt.Errorf("unknown format '%v' please use [yaml|xml|props]", format)
+		return 0, fmt.Errorf("unknown format '%v' please use [yaml|json|props|csv|tsv|xml]", format)
 	}
 }
 
-func InputFormatFromFilename(filename string, defaultFormat string) string {
+func FormatFromFilename(filename string) string {
+
 	if filename != "" {
-		GetLogger().Debugf("checking filename '%s' for inputFormat", filename)
+		GetLogger().Debugf("checking file extension '%s' for auto format detection", filename)
 		nPos := strings.LastIndex(filename, ".")
 		if nPos > -1 {
-			inputFormat := filename[nPos+1:]
-			GetLogger().Debugf("detected inputFormat '%s'", inputFormat)
-			return inputFormat
+			format := filename[nPos+1:]
+			GetLogger().Debugf("detected format '%s'", format)
+			return format
 		}
 	}
 
-	GetLogger().Debugf("using default inputFormat '%s'", defaultFormat)
-	return defaultFormat
+	GetLogger().Debugf("using default inputFormat 'yaml'")
+	return "yaml"
 }

pkg/yqlib/operator_filter.go

@@ -30,4 +30,3 @@ func filterOperator(d *dataTreeNavigator, context Context, expressionNode *Expre
 	}
 	return context.ChildContext(results), nil
 }
-

pkg/yqlib/operator_filter_test.go

@@ -7,22 +7,22 @@ import (
 var filterOperatorScenarios = []expressionScenario{
 	{
 		description: "Filter array",
-		document:   `[1,2,3]`,
-		expression: `filter(. < 3)`,
+		document:    `[1,2,3]`,
+		expression:  `filter(. < 3)`,
 		expected: []string{
 			"D0, P[], (!!seq)::[1, 2]\n",
 		},
 	},
 	{
-		skipDoc: true,
-		document:    `[1,2,3]`,
-		expression:  `filter(. > 1)`,
+		skipDoc:    true,
+		document:   `[1,2,3]`,
+		expression: `filter(. > 1)`,
 		expected: []string{
 			"D0, P[], (!!seq)::[2, 3]\n",
 		},
 	},
 	{
-		skipDoc: true,
+		skipDoc:     true,
 		description: "Filter array to empty",
 		document:    `[1,2,3]`,
 		expression:  `filter(. > 4)`,
@@ -31,7 +31,7 @@ var filterOperatorScenarios = []expressionScenario{
 		},
 	},
 	{
-		skipDoc: true,
+		skipDoc:     true,
 		description: "Filter empty array",
 		document:    `[]`,
 		expression:  `filter(. > 1)`,

pkg/yqlib/printer.go

@@ -33,11 +33,11 @@ const (
 
 func OutputFormatFromString(format string) (PrinterOutputFormat, error) {
 	switch format {
-	case "yaml", "y":
+	case "yaml", "y", "yml":
 		return YamlOutputFormat, nil
 	case "json", "j":
 		return JSONOutputFormat, nil
-	case "props", "p":
+	case "props", "p", "properties":
 		return PropsOutputFormat, nil
 	case "csv", "c":
 		return CSVOutputFormat, nil