fauxrpc

README

FauxRPC

FauxRPC is a powerful tool that empowers you to accelerate development and testing by effortlessly generating fake implementations of gRPC, gRPC-Web, Connect, and REST services. If you have a protobuf-based workflow, this tool could help.

Why FauxRPC?

• Faster Development & Testing: Work independently without relying on fully functional backend services.
• Isolation & Control: Test frontend components in isolation with controlled fake data.
• Multi-Protocol Support: Supports multiple protocols (gRPC, gRPC-Web, Connect, and REST).
• Prototyping & Demos: Create prototypes and demos quickly without building the full backend. Fake it till you make it.
• API Stubs: Define static or dynamic API responses with powerful stubs featuring CEL expressions for precise behavior control. Stubs can be defined using config files or dynamically at runtime.
• Improved Collaboration: Bridge the gap between frontend and backend teams.
• Plays well with others: Test data from FauxRPC will try to automatically follow any protovalidate constraints that are defined.
• Request Validation: Ensure data integrity with automatic request validation using protovalidate. Catch errors early and prevent invalid data from reaching your application logic.

See the the documentation website for more!

Get Started

Install via source

go install github.com/sudorandom/fauxrpc/cmd/fauxrpc@latest

Pre-built binaries

Binaries are built for several platforms for each release. See the latest ones on the releases page.

Quick Start

Pass protobuf descriptors to FauxRPC and a test server will be created, returning random fake data!

$ fauxrpc run --schema=service.binpb

That's... it. Now you can call it with your gRPC/gRPC-Web/Connect clients:

$ buf curl --http2-prior-knowledge http://127.0.0.1:6660/my.own.v1.service/HelloWorld
{
  "text": "Thundercats."
}

Go to the documentation website for more!

Documentation

Index

• Variables
• func Bool(fd protoreflect.FieldDescriptor, opts GenOptions) bool
• func Bytes(fd protoreflect.FieldDescriptor, opts GenOptions) []byte
• func Enum(fd protoreflect.FieldDescriptor, opts GenOptions) protoreflect.EnumNumber
• func FieldValue(fd protoreflect.FieldDescriptor, opts GenOptions) *protoreflect.Value
• func Fixed32(fd protoreflect.FieldDescriptor, opts GenOptions) uint32
• func Fixed64(fd protoreflect.FieldDescriptor, opts GenOptions) uint64
• func Float32(fd protoreflect.FieldDescriptor, opts GenOptions) float32
• func Float64(fd protoreflect.FieldDescriptor, opts GenOptions) float64
• func GoogleDuration(fd protoreflect.FieldDescriptor, opts GenOptions) *durationpb.Duration
• func GoogleTimestamp(fd protoreflect.FieldDescriptor, opts GenOptions) *timestamppb.Timestamp
• func GoogleValue(fd protoreflect.FieldDescriptor, opts GenOptions) *structpb.Value
• func Int32(fd protoreflect.FieldDescriptor, opts GenOptions) int32
• func Int64(fd protoreflect.FieldDescriptor, opts GenOptions) int64
• func Map(msg protoreflect.Message, fd protoreflect.FieldDescriptor, opts GenOptions) *protoreflect.Value
• func NewFauxFaker() *fauxFaker
• func NewMessage(md protoreflect.MessageDescriptor, opts GenOptions) (protoreflect.ProtoMessage, error)
• func NewMultiFaker(fakers []ProtoFaker) multiFaker
• func Repeated(msg protoreflect.Message, fd protoreflect.FieldDescriptor, opts GenOptions) *protoreflect.Value
• func SFixed32(fd protoreflect.FieldDescriptor, opts GenOptions) int32
• func SFixed64(fd protoreflect.FieldDescriptor, opts GenOptions) int64
• func SInt32(fd protoreflect.FieldDescriptor, opts GenOptions) int32
• func SInt64(fd protoreflect.FieldDescriptor, opts GenOptions) int64
• func SetDataOnMessage(msg protoreflect.ProtoMessage, opts GenOptions) error
• func String(fd protoreflect.FieldDescriptor, opts GenOptions) string
• func UInt32(fd protoreflect.FieldDescriptor, opts GenOptions) uint32
• func UInt64(fd protoreflect.FieldDescriptor, opts GenOptions) uint64
• type GenOptions
  • func (st GenOptions) GetContext() context.Context
• type ProtoFaker

Examples

• NewMessage
• SetDataOnMessage

Variables

var (
	ErrNotFaked = errors.New("no data was faked either because there was no relevant data or the faker was just out of faker juice")
)

Functions

func Bool

func Bool(fd protoreflect.FieldDescriptor, opts GenOptions) bool

Bool returns a fake boolean value given a field descriptor.

func Bytes

func Bytes(fd protoreflect.FieldDescriptor, opts GenOptions) []byte

Bytes returns a fake []byte value given a field descriptor.

func Enum

func Enum(fd protoreflect.FieldDescriptor, opts GenOptions) protoreflect.EnumNumber

Enum returns a fake enum value given a field descriptor.

func FieldValue

func FieldValue(fd protoreflect.FieldDescriptor, opts GenOptions) *protoreflect.Value

func Fixed32

func Fixed32(fd protoreflect.FieldDescriptor, opts GenOptions) uint32

Fixed32 returns a fake fixed32 value given a field descriptor.

func Fixed64

func Fixed64(fd protoreflect.FieldDescriptor, opts GenOptions) uint64

Fixed64 returns a fake fixed64 value given a field descriptor.

func Float32

func Float32(fd protoreflect.FieldDescriptor, opts GenOptions) float32

Float32 returns a fake float32 value given a field descriptor.

func Float64

func Float64(fd protoreflect.FieldDescriptor, opts GenOptions) float64

Float64 returns a fake float64 value given a field descriptor.

func GoogleDuration

func GoogleDuration(fd protoreflect.FieldDescriptor, opts GenOptions) *durationpb.Duration

GoogleDuration generates a random google.protobuf.Duration value.

func GoogleTimestamp

func GoogleTimestamp(fd protoreflect.FieldDescriptor, opts GenOptions) *timestamppb.Timestamp

GoogleTimestamp generates a random google.protobuf.Timestamp value.

func GoogleValue

func GoogleValue(fd protoreflect.FieldDescriptor, opts GenOptions) *structpb.Value

func Int32

func Int32(fd protoreflect.FieldDescriptor, opts GenOptions) int32

Int32 returns a fake int32 value given a field descriptor.

func Int64

func Int64(fd protoreflect.FieldDescriptor, opts GenOptions) int64

Int64 returns a fake int64 value given a field descriptor.

func Map

func Map(msg protoreflect.Message, fd protoreflect.FieldDescriptor, opts GenOptions) *protoreflect.Value

Map returns a fake repeated value given a field descriptor.

func NewFauxFaker

func NewFauxFaker() *fauxFaker

func NewMessage

func NewMessage(md protoreflect.MessageDescriptor, opts GenOptions) (protoreflect.ProtoMessage, error)

NewMessage creates a new message populated with fake data given a protoreflect.MessageDescriptor

Example

package main

import (
	"fmt"

	elizav1 "buf.build/gen/go/connectrpc/eliza/protocolbuffers/go/connectrpc/eliza/v1"
	"github.com/sudorandom/fauxrpc"
	"google.golang.org/protobuf/encoding/protojson"
)

func main() {
	msg, _ := fauxrpc.NewMessage(elizav1.File_connectrpc_eliza_v1_eliza_proto.Messages().ByName("SayResponse"), fauxrpc.GenOptions{})
	b, _ := protojson.MarshalOptions{Indent: "  "}.Marshal(msg)
	fmt.Println(string(b))
}

func NewMultiFaker

func NewMultiFaker(fakers []ProtoFaker) multiFaker

func Repeated

func Repeated(msg protoreflect.Message, fd protoreflect.FieldDescriptor, opts GenOptions) *protoreflect.Value

Repeated returns a fake repeated value given a field descriptor.

func SFixed32

func SFixed32(fd protoreflect.FieldDescriptor, opts GenOptions) int32

SFixed32 returns a fake sfixedint32 value given a field descriptor.

func SFixed64

func SFixed64(fd protoreflect.FieldDescriptor, opts GenOptions) int64

SFixed64 returns a fake sfixed64 value given a field descriptor.

func SInt32

func SInt32(fd protoreflect.FieldDescriptor, opts GenOptions) int32

SInt32 returns a fake sint32 value given a field descriptor.

func SInt64

func SInt64(fd protoreflect.FieldDescriptor, opts GenOptions) int64

SInt64 returns a fake sint64 value given a field descriptor.

func SetDataOnMessage

func SetDataOnMessage(msg protoreflect.ProtoMessage, opts GenOptions) error

SetDataOnMessage generates fake data given a protoreflect.ProtoMessage and sets the field values.

Example

package main

import (
	"fmt"
	"log"

	elizav1 "buf.build/gen/go/connectrpc/eliza/protocolbuffers/go/connectrpc/eliza/v1"
	"github.com/sudorandom/fauxrpc"
	"google.golang.org/protobuf/encoding/protojson"
)

func main() {
	msg := &elizav1.SayResponse{}
	if err := fauxrpc.SetDataOnMessage(msg, fauxrpc.GenOptions{}); err != nil {
		log.Fatalf("error: %s", err) // handle error
	}
	b, _ := protojson.MarshalOptions{Indent: "  "}.Marshal(msg)
	fmt.Println(string(b))
}

func String

func String(fd protoreflect.FieldDescriptor, opts GenOptions) string

String returns a fake string value given a field descriptor.

func UInt32

func UInt32(fd protoreflect.FieldDescriptor, opts GenOptions) uint32

UInt32 returns a fake uint32 value given a field descriptor.

func UInt64

func UInt64(fd protoreflect.FieldDescriptor, opts GenOptions) uint64

UInt64 returns a fake uint64 value given a field descriptor.

Types

type GenOptions

type GenOptions struct {
	MaxDepth int
	Faker    *gofakeit.Faker
	Context  context.Context
	// contains filtered or unexported fields
}

func (GenOptions) GetContext

func (st GenOptions) GetContext() context.Context

type ProtoFaker

type ProtoFaker interface {
	SetDataOnMessage(msg protoreflect.ProtoMessage, opts GenOptions) error
}