Added code generation for commands

examples/chat/room_commands.go

@@ -1,5 +1,7 @@
 package chat
 
+//go:generate go run ../../gen/commandgenerator/main.go -id RoomID -aggregateType room
+
 type OnBoardRoom struct {
 	RoomID   string `json:"roomID"`
 	UserID   string `json:"userID"`
@@ -35,29 +37,3 @@ type BanUserFromRoom struct {
 	Reason  string `json:"reason"`
 	Timeout uint   `json:"timeout"`
 }
-
-// TODO: Generate code below
-
-func (c OnBoardRoom) AggregateID() string   { return c.RoomID }
-func (c OnBoardRoom) AggregateType() string { return "room" }
-func (c OnBoardRoom) CommandType() string   { return "OnBoardRoom" }
-
-func (c JoinRoom) AggregateID() string   { return c.RoomID }
-func (c JoinRoom) AggregateType() string { return "room" }
-func (c JoinRoom) CommandType() string   { return "JoinRoom" }
-
-func (c SendMessageToRoom) AggregateID() string   { return c.RoomID }
-func (c SendMessageToRoom) AggregateType() string { return "room" }
-func (c SendMessageToRoom) CommandType() string   { return "SendMessageToRoom" }
-
-func (c SendPrivateMessageToRoom) AggregateID() string   { return c.RoomID }
-func (c SendPrivateMessageToRoom) AggregateType() string { return "room" }
-func (c SendPrivateMessageToRoom) CommandType() string   { return "SendPrivateMessageToRoom" }
-
-func (c RemoveUserFromRoom) AggregateID() string   { return c.RoomID }
-func (c RemoveUserFromRoom) AggregateType() string { return "room" }
-func (c RemoveUserFromRoom) CommandType() string   { return "RemoveUserFromRoom" }
-
-func (c BanUserFromRoom) AggregateID() string   { return c.RoomID }
-func (c BanUserFromRoom) AggregateType() string { return "room" }
-func (c BanUserFromRoom) CommandType() string   { return "BanUserFromRoom" }

examples/chat/user_commands.go

@@ -1,5 +1,7 @@
 package chat
 
+//go:generate go run ../../gen/commandgenerator/main.go -id UserID -aggregateType user
+
 type OnBoardUser struct {
 	UserID string `json:"userID"`
 	Name   string `json:"name"`
@@ -9,13 +11,3 @@ type WarnUser struct {
 	UserID string `json:"userID"`
 	Reason string `json:"reason"`
 }
-
-// TODO: Generate code below
-
-func (c OnBoardUser) AggregateID() string   { return c.UserID }
-func (c OnBoardUser) AggregateType() string { return "user" }
-func (c OnBoardUser) CommandType() string   { return "OnBoardUser" }
-
-func (c WarnUser) AggregateID() string   { return c.UserID }
-func (c WarnUser) AggregateType() string { return "user" }
-func (c WarnUser) CommandType() string   { return "WarnUser" }

gen/commandgenerator/main.go

@@ -0,0 +1,55 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"path"
+	"strings"
+
+	"github.com/inklabs/rangedb/pkg/commandgenerator"
+	"github.com/inklabs/rangedb/pkg/structparser"
+)
+
+func main() {
+	pkg := flag.String("package", os.Getenv("GOPACKAGE"), "package")
+	id := flag.String("id", "", "id")
+	aggregateType := flag.String("aggregateType", "", "aggregate name")
+	inFilePath := flag.String("inFile", os.Getenv("GOFILE"), "input filename containing commands")
+	outFilePath := flag.String("outFile", "", "output file name")
+	flag.Parse()
+
+	if *outFilePath == "" {
+		if *outFilePath == "" {
+			fileName := strings.TrimSuffix(*inFilePath, path.Ext(*inFilePath))
+			*outFilePath = fmt.Sprintf("%s_gen.go", fileName)
+		}
+	}
+
+	commandsFile, err := os.Open(*inFilePath)
+	if err != nil {
+		log.Fatalf("unable to open (%s): %v", *inFilePath, err)
+	}
+	defer func() {
+		_ = commandsFile.Close()
+	}()
+
+	commands, err := structparser.GetStructNames(commandsFile)
+	if err != nil {
+		log.Fatalf("unable to extract commands: %v", err)
+	}
+
+	outFile, err := os.Create(*outFilePath)
+	if err != nil {
+		log.Fatalf("unable to create aggreate file: %v", err)
+	}
+	defer func() {
+		_ = outFile.Close()
+	}()
+
+	err = commandgenerator.Write(outFile, commands, *pkg, *id, *aggregateType)
+	if err != nil {
+		log.Fatalf("unable to write to aggregates file: %v", err)
+	}
+}

pkg/aggregategenerator/write_aggregate_test.go

@@ -156,5 +156,4 @@ func (a *thing) raise(events ...rangedb.Event) {
 `
 		assert.Equal(t, expectedOut, out.String())
 	})
-
 }

pkg/commandgenerator/write_command.go

@@ -0,0 +1,45 @@
+package commandgenerator
+
+import (
+	"fmt"
+	"io"
+	"text/template"
+	"time"
+)
+
+var NowFunc = time.Now
+
+func Write(out io.Writer, commands []string, pkg, id, aggregateType string) error {
+	if len(commands) < 1 {
+		return fmt.Errorf("no commands found")
+	}
+
+	return fileTemplate.Execute(out, templateData{
+		Timestamp:     NowFunc(),
+		Commands:      commands,
+		AggregateType: aggregateType,
+		ID:            id,
+		Package:       pkg,
+	})
+}
+
+type templateData struct {
+	Timestamp     time.Time
+	Commands      []string
+	AggregateType string
+	ID            string
+	Package       string
+}
+
+var fileTemplate = template.Must(template.New("").Parse(`// Code generated by go generate; DO NOT EDIT.
+// This file was generated at
+// {{ .Timestamp }}
+package {{ $.Package }}
+
+{{- range .Commands }}
+
+func (c {{ . }}) AggregateID() string   { return c.{{ $.ID }} }
+func (c {{ . }}) AggregateType() string { return "{{ $.AggregateType }}" }
+func (c {{ . }}) CommandType() string   { return "{{ . }}" }
+{{- end }}
+`))

pkg/commandgenerator/write_command_test.go

@@ -0,0 +1,88 @@
+package commandgenerator_test
+
+import (
+	"bytes"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/inklabs/rangedb/pkg/commandgenerator"
+)
+
+func TestWrite(t *testing.T) {
+	const (
+		pkg           = "mypkg"
+		id            = "ID"
+		aggregateType = "thing"
+	)
+	commandgenerator.NowFunc = func() time.Time {
+		return time.Unix(1611080667, 25600800).UTC()
+	}
+
+	t.Run("no commands found", func(t *testing.T) {
+		// Given
+		var commands []string
+		var out bytes.Buffer
+
+		// When
+		err := commandgenerator.Write(&out, commands, pkg, id, aggregateType)
+
+		// Then
+		require.EqualError(t, err, "no commands found")
+	})
+
+	t.Run("single command", func(t *testing.T) {
+		// Given
+		commands := []string{
+			"DoThing",
+		}
+		var out bytes.Buffer
+
+		// When
+		err := commandgenerator.Write(&out, commands, pkg, id, aggregateType)
+
+		// Then
+		require.NoError(t, err)
+		expectedOut := `// Code generated by go generate; DO NOT EDIT.
+// This file was generated at
+// 2021-01-19 18:24:27.0256008 +0000 UTC
+package mypkg
+
+func (c DoThing) AggregateID() string   { return c.ID }
+func (c DoThing) AggregateType() string { return "thing" }
+func (c DoThing) CommandType() string   { return "DoThing" }
+`
+		assert.Equal(t, expectedOut, out.String())
+	})
+
+	t.Run("two commands", func(t *testing.T) {
+		// Given
+		commands := []string{
+			"DoThing",
+			"DoAnother",
+		}
+		var out bytes.Buffer
+
+		// When
+		err := commandgenerator.Write(&out, commands, pkg, id, aggregateType)
+
+		// Then
+		require.NoError(t, err)
+		expectedOut := `// Code generated by go generate; DO NOT EDIT.
+// This file was generated at
+// 2021-01-19 18:24:27.0256008 +0000 UTC
+package mypkg
+
+func (c DoThing) AggregateID() string   { return c.ID }
+func (c DoThing) AggregateType() string { return "thing" }
+func (c DoThing) CommandType() string   { return "DoThing" }
+
+func (c DoAnother) AggregateID() string   { return c.ID }
+func (c DoAnother) AggregateType() string { return "thing" }
+func (c DoAnother) CommandType() string   { return "DoAnother" }
+`
+		assert.Equal(t, expectedOut, out.String())
+	})
+}