Print results in tabulated format (#351)

* Print results in tabulated format

* Address code review comments

* Add unit test

* Reduce lines

* Escape input

* Rename variable

* Update README

* Handle nil values correctly

* Add test coverage

CHANGELOG.md

@@ -1,4 +1,7 @@
 # Changelog
+## v3.1.1 (unreleased)
+ - Print CLI results in tabulated format (#351)
+
 ## v3.1.0 (2018-07-12)
  - Add functionality to not invalidate cache when upsert (#341)
  - Add query (read/range) support to CLI (#342)

cmd/dosa/query.go

@@ -99,9 +99,7 @@ func (c *QueryCmd) doQueryOp(f func(ShellQueryClient, context.Context, []*queryO
 		return err
 	}
 
-	printResult(results)
-
-	return nil
+	return printResults(results)
 }
 
 // QueryRead holds the options for 'query read'

cmd/dosa/query_test.go

@@ -117,7 +117,7 @@ func TestQuery_Range_Happy(t *testing.T) {
 			assert.Len(t, columnConditions, 1)
 			assert.Len(t, columnConditions["int64key"], 1)
 			assert.Equal(t, []string{"strkey", "int64key"}, minimumFields)
-		}).Return([]map[string]dosa.FieldValue{}, "", nil)
+		}).Return([]map[string]dosa.FieldValue{{"key": "value"}}, "", nil)
 
 	mc.EXPECT().Shutdown().Return(nil)
 

cmd/dosa/util.go

@@ -22,9 +22,12 @@ package main
 
 import (
 	"fmt"
+	"os"
 	"reflect"
+	"sort"
 	"strconv"
 	"strings"
+	"text/tabwriter"
 	"time"
 
 	"github.com/pkg/errors"
@@ -114,16 +117,49 @@ func strToFieldValue(t dosa.Type, s string) (dosa.FieldValue, error) {
 	}
 }
 
-func printResult(res []map[string]dosa.FieldValue) {
-	if len(res) == 0 {
-		fmt.Println("Error: not found")
-		return
+func getFields(results []map[string]dosa.FieldValue) []string {
+	fieldSet := make(map[string]bool)
+	for _, result := range results {
+		for field := range result {
+			fieldSet[field] = true
+		}
+	}
+	var fields []string
+	for field := range fieldSet {
+		fields = append(fields, field)
+	}
+	sort.Strings(fields)
+	return fields
+}
+
+func printResults(results []map[string]dosa.FieldValue) error {
+	w := tabwriter.NewWriter(os.Stdout, 0, 0, 3, ' ', tabwriter.Debug|tabwriter.StripEscape)
+	if len(results) == 0 {
+		return errors.New("Empty results")
+	}
+	fields := getFields(results)
+	if _, err := fmt.Fprintln(w, strings.Join(fields, "\t")); err != nil {
+		return errors.WithStack(err)
 	}
-	fmt.Println("Results:")
-	for _, fieldValues := range res {
-		for field, value := range fieldValues {
-			fmt.Printf("%s: %v\n", field, reflect.Indirect(reflect.ValueOf(value)))
+	values := make([]string, len(fields))
+	for _, result := range results {
+		for idx, field := range fields {
+			var value string
+			if _, ok := result[field]; ok {
+				value = fmt.Sprintf(
+					"%s%v%s",
+					[]byte{tabwriter.Escape},
+					reflect.Indirect(reflect.ValueOf(result[field])),
+					[]byte{tabwriter.Escape},
+				)
+			} else {
+				value = "nil"
+			}
+			values[idx] = value
+		}
+		if _, err := fmt.Fprintln(w, strings.Join(values, "\t")); err != nil {
+			return errors.WithStack(err)
 		}
-		fmt.Printf("\n")
 	}
+	return w.Flush()
 }

cmd/dosa/util_test.go

@@ -82,6 +82,31 @@ func TestSetQueryFieldValues(t *testing.T) {
 	assert.Contains(t, err.Error(), "is not a valid field for")
 }
 
+func TestGetfields(t *testing.T) {
+	fields := []map[string]dosa.FieldValue{
+		{"id": dosa.FieldValue(int32(1)), "name": dosa.FieldValue("foo")},
+		{"name": dosa.FieldValue("bar"), "address": dosa.FieldValue("bar")},
+	}
+	assert.Equal(t, getFields(fields), []string{"address", "id", "name"})
+}
+
+func TestPrintResults(t *testing.T) {
+	results := []map[string]dosa.FieldValue{
+		{
+			"id":   dosa.FieldValue(int32(1)),
+			"uuid": dosa.FieldValue(dosa.UUID("3e4befa0-69d3-11e8-95b0-d55aa227a290")),
+		},
+	}
+	err := printResults(results)
+	assert.NoError(t, err)
+}
+
+func TestPrintResultsEmpty(t *testing.T) {
+	results := []map[string]dosa.FieldValue{}
+	err := printResults(results)
+	assert.Error(t, err)
+}
+
 func TestStrToFieldValue(t *testing.T) {
 	tStr := "2018-06-11T13:03:01Z"
 	ts, _ := time.Parse(time.RFC3339, tStr)