cmd: added new output formats. fixes #82. (#93)

Now you can change the output format to 2 new ones: json and csv.

- Added json support
- Added csv support
- Now the table output format is called 'pretty'. It is the default format.

Author: ajnavarro

Diff for: cmd/gitql/query.go

@@ -9,17 +9,18 @@ import (
 
 	"github.com/gitql/gitql"
 	gitqlgit "github.com/gitql/gitql/git"
+	"github.com/gitql/gitql/internal/format"
 	"github.com/gitql/gitql/sql"
 
-	"github.com/olekukonko/tablewriter"
 	"gopkg.in/src-d/go-git.v4"
 )
 
 type CmdQuery struct {
 	cmd
 
-	Path string `short:"p" long:"path" description:"Path where the git repository is located"`
-	Args struct {
+	Path   string `short:"p" long:"path" description:"Path where the git repository is located"`
+	Format string `short:"f" long:"format" default:"pretty" description:"Ouptut format. Formats supported: pretty, csv, json."`
+	Args   struct {
 		SQL string `positional-arg-name:"sql" required:"true" description:"SQL query to execute"`
 	} `positional-args:"yes"`
 
@@ -86,34 +87,39 @@ func (c *CmdQuery) executeQuery() error {
 		return err
 	}
 
-	c.printQuery(schema, iter)
-
-	return nil
+	return c.printQuery(schema, iter)
 }
 
-func (c *CmdQuery) printQuery(schema sql.Schema, iter sql.RowIter) {
-	w := tablewriter.NewWriter(os.Stdout)
+func (c *CmdQuery) printQuery(schema sql.Schema, iter sql.RowIter) error {
+	f, err := format.NewFormat(c.Format, os.Stdout)
+	if err != nil {
+		return err
+	}
+
 	headers := []string{}
 	for _, f := range schema {
 		headers = append(headers, f.Name)
 	}
-	w.SetHeader(headers)
+
+	if err := f.WriteHeader(headers); err != nil {
+		return err
+	}
+
 	for {
 		row, err := iter.Next()
 		if err == io.EOF {
 			break
 		}
 		if err != nil {
-			fmt.Printf("Error: %v\n", err)
-			return
+			return err
 		}
-		rowStrings := []string{}
-		for _, v := range row.Fields() {
-			rowStrings = append(rowStrings, fmt.Sprintf("%v", v))
+
+		if err := f.Write(row.Fields()); err != nil {
+			return err
 		}
-		w.Append(rowStrings)
 	}
-	w.Render()
+
+	return f.Close()
 }
 
 func findDotGitFolder(path string) (string, error) {

Diff for: internal/format/common.go

@@ -0,0 +1,25 @@
+package format
+
+import (
+	"fmt"
+	"io"
+)
+
+type Format interface {
+	WriteHeader(headers []string) error
+	Write(line []interface{}) error
+	Close() error
+}
+
+func NewFormat(id string, w io.Writer) (Format, error) {
+	switch id {
+	case "pretty":
+		return NewPrettyFormat(w), nil
+	case "csv":
+		return NewCsvFormat(w), nil
+	case "json":
+		return NewJsonFormat(w), nil
+	default:
+		return nil, fmt.Errorf("format not supported: %v", id)
+	}
+}

Diff for: internal/format/common_test.go

@@ -0,0 +1,49 @@
+package format
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNewFormat_InvalidId(t *testing.T) {
+	assert := assert.New(t)
+
+	f, err := NewFormat("INVALID", bytes.NewBuffer(nil))
+	assert.Nil(f)
+	assert.NotNil(err)
+}
+
+func testNewFormat(id string, t *testing.T) {
+	assert := assert.New(t)
+
+	w := bytes.NewBuffer(nil)
+	f, err := NewFormat(id, w)
+	assert.Nil(err)
+	assert.NotNil(f)
+}
+
+func testFormat(fs *formatSpec, writer *bytes.Buffer, t *testing.T) {
+	assert := assert.New(t)
+
+	err := fs.Format.WriteHeader(fs.Headers)
+	assert.Nil(err)
+	for _, l := range fs.Lines {
+		err := fs.Format.Write(l)
+		assert.Nil(err)
+	}
+	err = fs.Format.Close()
+	assert.Nil(err)
+
+	assert.Equal(fs.Result, writer.String())
+
+	writer.Reset()
+}
+
+type formatSpec struct {
+	Headers []string
+	Lines   [][]interface{}
+	Format  Format
+	Result  string
+}

Diff for: internal/format/csv.go

@@ -0,0 +1,36 @@
+package format
+
+import (
+	"encoding/csv"
+	"fmt"
+	"io"
+)
+
+type CsvFormat struct {
+	cw *csv.Writer
+}
+
+func NewCsvFormat(w io.Writer) *CsvFormat {
+	return &CsvFormat{
+		cw: csv.NewWriter(w),
+	}
+}
+
+func (cf *CsvFormat) WriteHeader(headers []string) error {
+	return cf.cw.Write(headers)
+}
+
+func (cf *CsvFormat) Write(line []interface{}) error {
+	rowStrings := []string{}
+	for _, v := range line {
+		rowStrings = append(rowStrings, fmt.Sprintf("%v", v))
+	}
+
+	return cf.cw.Write(rowStrings)
+}
+
+func (cf *CsvFormat) Close() error {
+	cf.cw.Flush()
+
+	return nil
+}

Diff for: internal/format/csv_test.go

@@ -0,0 +1,24 @@
+package format
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestNewCsvFormat(t *testing.T) {
+	w := bytes.NewBuffer(nil)
+	testFormat(&formatSpec{
+		Format:  NewCsvFormat(w),
+		Result:  "a,b,c\na1,b1,c1\n",
+		Headers: []string{"a", "b", "c"},
+		Lines: [][]interface{}{
+			[]interface{}{
+				"a1", "b1", "c1",
+			},
+		},
+	}, w, t)
+}
+
+func TestNewFormat_Csv(t *testing.T) {
+	testNewFormat("csv", t)
+}

Diff for: internal/format/json.go

@@ -0,0 +1,36 @@
+package format
+
+import (
+	"encoding/json"
+	"io"
+)
+
+type JsonFormat struct {
+	je   *json.Encoder
+	keys []string
+}
+
+func NewJsonFormat(w io.Writer) *JsonFormat {
+	return &JsonFormat{
+		je: json.NewEncoder(w),
+	}
+}
+
+func (cf *JsonFormat) WriteHeader(headers []string) error {
+	cf.keys = headers
+
+	return nil
+}
+
+func (cf *JsonFormat) Write(line []interface{}) error {
+	j := make(map[string]interface{})
+	for i, k := range cf.keys {
+		j[k] = line[i]
+	}
+
+	return cf.je.Encode(j)
+}
+
+func (cf *JsonFormat) Close() error {
+	return nil
+}

Diff for: internal/format/json_test.go

@@ -0,0 +1,25 @@
+package format
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestNewJsonFormat(t *testing.T) {
+	w := bytes.NewBuffer(nil)
+	testFormat(&formatSpec{
+		Format:  NewJsonFormat(w),
+		Result:  "{\"a\":\"a1\",\"b\":\"b1\",\"c\":\"c1\"}\n",
+		Headers: []string{"a", "b", "c"},
+		Lines: [][]interface{}{
+			[]interface{}{
+				"a1", "b1", "c1",
+			},
+		},
+	}, w, t)
+}
+
+
+func TestNewFormat_Json(t *testing.T) {
+	testNewFormat("json", t)
+}

Diff for: internal/format/pretty.go

@@ -0,0 +1,40 @@
+package format
+
+import (
+	"fmt"
+	"io"
+
+	"github.com/olekukonko/tablewriter"
+)
+
+type PrettyFormat struct {
+	tw *tablewriter.Table
+}
+
+func NewPrettyFormat(w io.Writer) *PrettyFormat {
+	return &PrettyFormat{
+		tw: tablewriter.NewWriter(w),
+	}
+}
+
+func (pf *PrettyFormat) WriteHeader(headers []string) error {
+	pf.tw.SetHeader(headers)
+
+	return nil
+}
+
+func (pf *PrettyFormat) Write(line []interface{}) error {
+	rowStrings := []string{}
+	for _, v := range line {
+		rowStrings = append(rowStrings, fmt.Sprintf("%v", v))
+	}
+	pf.tw.Append(rowStrings)
+
+	return nil
+}
+
+func (pf *PrettyFormat) Close() error {
+	pf.tw.Render()
+
+	return nil
+}

Diff for: internal/format/pretty_test.go

@@ -0,0 +1,26 @@
+package format
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestNewPrettyFormat(t *testing.T) {
+	w := bytes.NewBuffer(nil)
+	testFormat(&formatSpec{
+		Format: NewPrettyFormat(w),
+		Result: "+----+----+----+\n| A  | B  | C  |" +
+			"\n+----+----+----+\n| a1 | b1 | c1 |" +
+			"\n+----+----+----+\n",
+		Headers: []string{"a", "b", "c"},
+		Lines: [][]interface{}{
+			[]interface{}{
+				"a1", "b1", "c1",
+			},
+		},
+	}, w, t)
+}
+
+func TestNewFormat_Pretty(t *testing.T) {
+	testNewFormat("pretty", t)
+}