Add Get* methods to Payload type

README.md

@@ -66,11 +66,11 @@ func main() {
 func handler(t *asynq.Task) error {
     switch t.Type {
         case "send_welcome_email":
-            rid, ok := t.Payload["recipient_id"]
-            if !ok {
-                return fmt.Errorf("recipient_id not found in payload")
+            id, err := t.Payload.GetInt("recipient_id")
+            if err != nil{
+                return err
             }
-            fmt.Printf("Send Welcome Email to %d\n", rid.(int))
+            fmt.Printf("Send Welcome Email to %d\n", id)
 
         // ... handle other task types.
 

asynq.go

@@ -24,9 +24,8 @@ type Task struct {
 	// Type indicates the kind of the task to be performed.
 	Type string
 
-	// Payload is an arbitrary data needed for task execution.
-	// The value has to be serializable.
-	Payload map[string]interface{}
+	// Payload holds data needed for the task execution.
+	Payload Payload
 }
 
 // RedisConfig specifies redis configurations.

go.mod

@@ -9,6 +9,7 @@ require (
 	github.com/pelletier/go-toml v1.6.0 // indirect
 	github.com/rs/xid v1.2.1
 	github.com/spf13/afero v1.2.2 // indirect
+	github.com/spf13/cast v1.3.1
 	github.com/spf13/cobra v0.0.5
 	github.com/spf13/jwalterweatherman v1.1.0 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect

go.sum

@@ -115,6 +115,8 @@ github.com/spf13/afero v1.2.2 h1:5jhuqJyZCZf2JRofRvN/nIFgIWNzPa3/Vz8mYylgbWc=
 github.com/spf13/afero v1.2.2/go.mod h1:9ZxEEn6pIJ8Rxe320qSDBk6AsU0r9pR7Q4OcevTdifk=
 github.com/spf13/cast v1.3.0 h1:oget//CVOEoFewqQxwr0Ej5yjygnqGkvggSE/gB35Q8=
 github.com/spf13/cast v1.3.0/go.mod h1:Qx5cxh0v+4UWYiBimWS+eyWzqEqokIECu5etghLkUJE=
+github.com/spf13/cast v1.3.1 h1:nFm6S0SMdyzrzcmThSipiEubIDy8WEXKNZ0UOgiRpng=
+github.com/spf13/cast v1.3.1/go.mod h1:Qx5cxh0v+4UWYiBimWS+eyWzqEqokIECu5etghLkUJE=
 github.com/spf13/cobra v0.0.5 h1:f0B+LkLX6DtmRH1isoNA9VTtNUK9K8xYd28JNNfOv/s=
 github.com/spf13/cobra v0.0.5/go.mod h1:3K3wKZymM7VvHMDS9+Akkh4K60UwM26emMESw8tLCHU=
 github.com/spf13/jwalterweatherman v1.0.0 h1:XHEdyB+EcvlqZamSM4ZOMGlc93t6AcsBEu9Gc1vn7yk=

payload.go

@@ -0,0 +1,155 @@
+package asynq
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/spf13/cast"
+)
+
+// Payload is an arbitrary data needed for task execution.
+// The values have to be JSON serializable.
+type Payload map[string]interface{}
+
+type errKeyNotFound struct {
+	key string
+}
+
+func (e *errKeyNotFound) Error() string {
+	return fmt.Sprintf("key %q does not exist", e.key)
+}
+
+// GetString returns a string value if a string type is associated with
+// the key, otherwise reports an error.
+func (p Payload) GetString(key string) (string, error) {
+	v, ok := p[key]
+	if !ok {
+		return "", &errKeyNotFound{key}
+	}
+	return cast.ToStringE(v)
+}
+
+// GetInt returns an int value if a numeric type is associated with
+// the key, otherwise reports an error.
+func (p Payload) GetInt(key string) (int, error) {
+	v, ok := p[key]
+	if !ok {
+		return 0, &errKeyNotFound{key}
+	}
+	return cast.ToIntE(v)
+}
+
+// GetFloat64 returns a float64 value if a numeric type is associated with
+// the key, otherwise reports an error.
+func (p Payload) GetFloat64(key string) (float64, error) {
+	v, ok := p[key]
+	if !ok {
+		return 0, &errKeyNotFound{key}
+	}
+	return cast.ToFloat64E(v)
+}
+
+// GetBool returns a boolean value if a boolean type is associated with
+// the key, otherwise reports an error.
+func (p Payload) GetBool(key string) (bool, error) {
+	v, ok := p[key]
+	if !ok {
+		return false, &errKeyNotFound{key}
+	}
+	return cast.ToBoolE(v)
+}
+
+// GetStringSlice returns a slice of strings if a string slice type is associated with
+// the key, otherwise reports an error.
+func (p Payload) GetStringSlice(key string) ([]string, error) {
+	v, ok := p[key]
+	if !ok {
+		return nil, &errKeyNotFound{key}
+	}
+	return cast.ToStringSliceE(v)
+}
+
+// GetIntSlice returns a slice of ints if a int slice type is associated with
+// the key, otherwise reports an error.
+func (p Payload) GetIntSlice(key string) ([]int, error) {
+	v, ok := p[key]
+	if !ok {
+		return nil, &errKeyNotFound{key}
+	}
+	return cast.ToIntSliceE(v)
+}
+
+// GetStringMap returns a map of string to empty interface
+// if a correct map type is associated with the key,
+// otherwise reports an error.
+func (p Payload) GetStringMap(key string) (map[string]interface{}, error) {
+	v, ok := p[key]
+	if !ok {
+		return nil, &errKeyNotFound{key}
+	}
+	return cast.ToStringMapE(v)
+}
+
+// GetStringMapString returns a map of string to string
+// if a correct map type is associated with the key,
+// otherwise reports an error.
+func (p Payload) GetStringMapString(key string) (map[string]string, error) {
+	v, ok := p[key]
+	if !ok {
+		return nil, &errKeyNotFound{key}
+	}
+	return cast.ToStringMapStringE(v)
+}
+
+// GetStringMapStringSlice returns a map of string to string slice
+// if a correct map type is associated with the key,
+// otherwise reports an error.
+func (p Payload) GetStringMapStringSlice(key string) (map[string][]string, error) {
+	v, ok := p[key]
+	if !ok {
+		return nil, &errKeyNotFound{key}
+	}
+	return cast.ToStringMapStringSliceE(v)
+}
+
+// GetStringMapInt returns a map of string to int
+// if a correct map type is associated with the key,
+// otherwise reports an error.
+func (p Payload) GetStringMapInt(key string) (map[string]int, error) {
+	v, ok := p[key]
+	if !ok {
+		return nil, &errKeyNotFound{key}
+	}
+	return cast.ToStringMapIntE(v)
+}
+
+// GetStringMapBool returns a map of string to boolean
+// if a correct map type is associated with the key,
+// otherwise reports an error.
+func (p Payload) GetStringMapBool(key string) (map[string]bool, error) {
+	v, ok := p[key]
+	if !ok {
+		return nil, &errKeyNotFound{key}
+	}
+	return cast.ToStringMapBoolE(v)
+}
+
+// GetTime returns a time value if a correct map type is associated with the key,
+// otherwise reports an error.
+func (p Payload) GetTime(key string) (time.Time, error) {
+	v, ok := p[key]
+	if !ok {
+		return time.Time{}, &errKeyNotFound{key}
+	}
+	return cast.ToTimeE(v)
+}
+
+// GetDuration returns a duration value if a correct map type is associated with the key,
+// otherwise reports an error.
+func (p Payload) GetDuration(key string) (time.Duration, error) {
+	v, ok := p[key]
+	if !ok {
+		return 0, &errKeyNotFound{key}
+	}
+	return cast.ToDurationE(v)
+}

payload_test.go

@@ -0,0 +1,254 @@
+package asynq
+
+import (
+	"encoding/json"
+	"testing"
+	"time"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+func TestPayload(t *testing.T) {
+	names := []string{"luke", "anakin", "ray"}
+	primes := []int{2, 3, 5, 7, 11, 13, 17}
+	user := map[string]interface{}{"name": "Ken", "score": 3.14}
+	location := map[string]string{"address": "123 Main St.", "state": "NY", "zipcode": "10002"}
+	favs := map[string][]string{
+		"movies":   []string{"forrest gump", "star wars"},
+		"tv_shows": []string{"game of throwns", "HIMYM", "breaking bad"},
+	}
+	counter := map[string]int{
+		"a": 1,
+		"b": 101,
+		"c": 42,
+	}
+	features := map[string]bool{
+		"A": false,
+		"B": true,
+		"C": true,
+	}
+	now := time.Now()
+	duration := 15 * time.Minute
+
+	payload := Payload{
+		"greeting":  "Hello",
+		"user_id":   9876,
+		"pi":        3.1415,
+		"enabled":   false,
+		"names":     names,
+		"primes":    primes,
+		"user":      user,
+		"location":  location,
+		"favs":      favs,
+		"counter":   counter,
+		"features":  features,
+		"timestamp": now,
+		"duration":  duration,
+	}
+
+	gotStr, err := payload.GetString("greeting")
+	if gotStr != "Hello" || err != nil {
+		t.Errorf("Payload.GetString(%q) = %v, %v, want %v, nil",
+			"greeting", gotStr, err, "Hello")
+	}
+
+	gotInt, err := payload.GetInt("user_id")
+	if gotInt != 9876 || err != nil {
+		t.Errorf("Payload.GetInt(%q) = %v, %v, want, %v, nil",
+			"user_id", gotInt, err, 9876)
+	}
+
+	gotFloat, err := payload.GetFloat64("pi")
+	if gotFloat != 3.1415 || err != nil {
+		t.Errorf("Payload.GetFloat64(%q) = %v, %v, want, %v, nil",
+			"pi", gotFloat, err, 3.141592)
+	}
+
+	gotBool, err := payload.GetBool("enabled")
+	if gotBool != false || err != nil {
+		t.Errorf("Payload.GetBool(%q) = %v, %v, want, %v, nil",
+			"enabled", gotBool, err, false)
+	}
+
+	gotStrSlice, err := payload.GetStringSlice("names")
+	if diff := cmp.Diff(gotStrSlice, names); diff != "" {
+		t.Errorf("Payload.GetStringSlice(%q) = %v, %v, want %v, nil;\n(-want,+got)\n%s",
+			"names", gotStrSlice, err, names, diff)
+	}
+
+	gotIntSlice, err := payload.GetIntSlice("primes")
+	if diff := cmp.Diff(gotIntSlice, primes); diff != "" {
+		t.Errorf("Payload.GetIntSlice(%q) = %v, %v, want %v, nil;\n(-want,+got)\n%s",
+			"primes", gotIntSlice, err, primes, diff)
+	}
+
+	gotStrMap, err := payload.GetStringMap("user")
+	if diff := cmp.Diff(gotStrMap, user); diff != "" {
+		t.Errorf("Payload.GetStringMap(%q) = %v, %v, want %v, nil;\n(-want,+got)\n%s",
+			"user", gotStrMap, err, user, diff)
+	}
+
+	gotStrMapStr, err := payload.GetStringMapString("location")
+	if diff := cmp.Diff(gotStrMapStr, location); diff != "" {
+		t.Errorf("Payload.GetStringMapString(%q) = %v, %v, want %v, nil;\n(-want,+got)\n%s",
+			"location", gotStrMapStr, err, location, diff)
+	}
+
+	gotStrMapStrSlice, err := payload.GetStringMapStringSlice("favs")
+	if diff := cmp.Diff(gotStrMapStrSlice, favs); diff != "" {
+		t.Errorf("Payload.GetStringMapStringSlice(%q) = %v, %v, want %v, nil;\n(-want,+got)\n%s",
+			"favs", gotStrMapStrSlice, err, favs, diff)
+	}
+
+	gotStrMapInt, err := payload.GetStringMapInt("counter")
+	if diff := cmp.Diff(gotStrMapInt, counter); diff != "" {
+		t.Errorf("Payload.GetStringMapInt(%q) = %v, %v, want %v, nil;\n(-want,+got)\n%s",
+			"counter", gotStrMapInt, err, counter, diff)
+	}
+
+	gotStrMapBool, err := payload.GetStringMapBool("features")
+	if diff := cmp.Diff(gotStrMapBool, features); diff != "" {
+		t.Errorf("Payload.GetStringMapBool(%q) = %v, %v, want %v, nil;\n(-want,+got)\n%s",
+			"features", gotStrMapBool, err, features, diff)
+	}
+
+	gotTime, err := payload.GetTime("timestamp")
+	if !gotTime.Equal(now) {
+		t.Errorf("Payload.GetTime(%q) = %v, %v, want %v, nil",
+			"timestamp", gotTime, err, now)
+	}
+
+	gotDuration, err := payload.GetDuration("duration")
+	if gotDuration != duration {
+		t.Errorf("Payload.GetDuration(%q) = %v, %v, want %v, nil",
+			"duration", gotDuration, err, duration)
+	}
+}
+
+func TestPayloadWithMarshaling(t *testing.T) {
+	names := []string{"luke", "anakin", "ray"}
+	primes := []int{2, 3, 5, 7, 11, 13, 17}
+	user := map[string]interface{}{"name": "Ken", "score": 3.14}
+	location := map[string]string{"address": "123 Main St.", "state": "NY", "zipcode": "10002"}
+	favs := map[string][]string{
+		"movies":   []string{"forrest gump", "star wars"},
+		"tv_shows": []string{"game of throwns", "HIMYM", "breaking bad"},
+	}
+	counter := map[string]int{
+		"a": 1,
+		"b": 101,
+		"c": 42,
+	}
+	features := map[string]bool{
+		"A": false,
+		"B": true,
+		"C": true,
+	}
+	now := time.Now()
+	duration := 15 * time.Minute
+
+	in := Payload{
+		"subject":      "Hello",
+		"recipient_id": 9876,
+		"pi":           3.14,
+		"enabled":      true,
+		"names":        names,
+		"primes":       primes,
+		"user":         user,
+		"location":     location,
+		"favs":         favs,
+		"counter":      counter,
+		"features":     features,
+		"timestamp":    now,
+		"duration":     duration,
+	}
+
+	// encode and then decode
+	data, err := json.Marshal(in)
+	if err != nil {
+		t.Fatal(err)
+	}
+	var out Payload
+	err = json.Unmarshal(data, &out)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	gotStr, err := out.GetString("subject")
+	if gotStr != "Hello" || err != nil {
+		t.Errorf("Payload.GetString(%q) = %v, %v; want %q, nil",
+			"subject", gotStr, err, "Hello")
+	}
+
+	gotInt, err := out.GetInt("recipient_id")
+	if gotInt != 9876 || err != nil {
+		t.Errorf("Payload.GetInt(%q) = %v, %v; want %v, nil",
+			"recipient_id", gotInt, err, 9876)
+	}
+
+	gotFloat, err := out.GetFloat64("pi")
+	if gotFloat != 3.14 || err != nil {
+		t.Errorf("Payload.GetFloat64(%q) = %v, %v; want %v, nil",
+			"pi", gotFloat, err, 3.14)
+	}
+
+	gotBool, err := out.GetBool("enabled")
+	if gotBool != true || err != nil {
+		t.Errorf("Payload.GetBool(%q) = %v, %v; want %v, nil",
+			"enabled", gotBool, err, true)
+	}
+
+	gotStrSlice, err := out.GetStringSlice("names")
+	if diff := cmp.Diff(gotStrSlice, names); diff != "" {
+		t.Errorf("Payload.GetStringSlice(%q) = %v, %v, want %v, nil;\n(-want,+got)\n%s",
+			"names", gotStrSlice, err, names, diff)
+	}
+
+	gotIntSlice, err := out.GetIntSlice("primes")
+	if diff := cmp.Diff(gotIntSlice, primes); diff != "" {
+		t.Errorf("Payload.GetIntSlice(%q) = %v, %v, want %v, nil;\n(-want,+got)\n%s",
+			"primes", gotIntSlice, err, primes, diff)
+	}
+
+	gotStrMap, err := out.GetStringMap("user")
+	if diff := cmp.Diff(gotStrMap, user); diff != "" {
+		t.Errorf("Payload.GetStringMap(%q) = %v, %v, want %v, nil;\n(-want,+got)\n%s",
+			"user", gotStrMap, err, user, diff)
+	}
+
+	gotStrMapStr, err := out.GetStringMapString("location")
+	if diff := cmp.Diff(gotStrMapStr, location); diff != "" {
+		t.Errorf("Payload.GetStringMapString(%q) = %v, %v, want %v, nil;\n(-want,+got)\n%s",
+			"location", gotStrMapStr, err, location, diff)
+	}
+
+	gotStrMapStrSlice, err := out.GetStringMapStringSlice("favs")
+	if diff := cmp.Diff(gotStrMapStrSlice, favs); diff != "" {
+		t.Errorf("Payload.GetStringMapStringSlice(%q) = %v, %v, want %v, nil;\n(-want,+got)\n%s",
+			"favs", gotStrMapStrSlice, err, favs, diff)
+	}
+
+	gotStrMapInt, err := out.GetStringMapInt("counter")
+	if diff := cmp.Diff(gotStrMapInt, counter); diff != "" {
+		t.Errorf("Payload.GetStringMapInt(%q) = %v, %v, want %v, nil;\n(-want,+got)\n%s",
+			"counter", gotStrMapInt, err, counter, diff)
+	}
+
+	gotStrMapBool, err := out.GetStringMapBool("features")
+	if diff := cmp.Diff(gotStrMapBool, features); diff != "" {
+		t.Errorf("Payload.GetStringMapBool(%q) = %v, %v, want %v, nil;\n(-want,+got)\n%s",
+			"features", gotStrMapBool, err, features, diff)
+	}
+
+	gotTime, err := out.GetTime("timestamp")
+	if !gotTime.Equal(now) {
+		t.Errorf("Payload.GetTime(%q) = %v, %v, want %v, nil",
+			"timestamp", gotTime, err, now)
+	}
+
+	gotDuration, err := out.GetDuration("duration")
+	if gotDuration != duration {
+		t.Errorf("Payload.GetDuration(%q) = %v, %v, want %v, nil",
+			"duration", gotDuration, err, duration)
+	}
+}