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Library

You can use FauxRPC as a Go library as well. Click here for the most up-to-date documentation.

The two most important functions are:

  • fauxrpc.SetDataOnMessage: When you have a concrete protobuf message type and want it populated with fake data.
  • fauxrpc.NewMessage: When you have a MessageDescriptor and just want a message. This is typical for more dynamic environments where you may not have generated types to use.

Here’s how you can generate a message filled with fake data, using the Eliza service 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{}
		fauxrpc.SetDataOnMessage(msg)
		b, err := protojson.MarshalOptions{Indent: "  "}.Marshal(msg)
		if err != nil {
			log.Fatalf("err: %s", err)
		}
		fmt.Println(string(b))
}

Example output:

{
  "sentence": "Jean shorts."
}

This text will be randomly generated each time. That’s nice, but Here’s one that’s a bit more complex.

package main

import (
	"fmt"
	"log"

	ownerv1 "buf.build/gen/go/bufbuild/registry/protocolbuffers/go/buf/registry/owner/v1"
	"github.com/sudorandom/fauxrpc"
	"google.golang.org/protobuf/encoding/protojson"
)

func main() {
		msg := &ownerv1.Owner{}
		fauxrpc.SetDataOnMessage(msg)
		b, err := protojson.MarshalOptions{Indent: "  "}.Marshal(msg)
		if err != nil {
			log.Fatalf("err: %s", err)
		}
		fmt.Println(string(b))
}

Example output:

{
  "organization": {
    "id": "a4cf6166453b49d9811cfdc169c36354",
    "createTime": "1912-06-01T16:45:13.510830647Z",
    "updateTime": "2009-04-03T13:11:31.216229245Z",
    "name": "xm0r3",
    "description": "Godard selvage.",
    "url": "https://www.dynamicreintermediate.name/robust/seize/metrics/b2c",
    "verificationStatus": "ORGANIZATION_VERIFICATION_STATUS_OFFICIAL"
  }
}

dynamicpb

Sometimes you don’t want to have the compiled protobuf code because you want the proxy or service to be more dynamic. In that case, you typically would use dynamicpb. FauxRPC works there, too. Here’s an 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 := fauxrpc.NewMessage(elizav1.File_connectrpc_eliza_v1_eliza_proto.Messages().ByName("SayResponse"))
    b, err := protojson.MarshalOptions{Indent: "  "}.Marshal(msg)
    if err != nil {
        log.Fatalf("err: %s", err)
    }
    fmt.Println(string(b))
}

There are other functions to help generate specific fields. Please reference the reference documentation for more information on that.

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