google.golang.org/genproto/googleapis/rpc v0.0.0-20250728155136-f173205681a0: errdetails.BadRequest

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify google.golang.org/genproto/googleapis/rpc/errdetails.BadRequest in pkg:golang/google.golang.org/genproto/googleapis/rpc@v0.0.0-20250728155136-f173205681a0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/google.golang.org/genproto/googleapis/rpc@v0.0.0-20250728155136-f173205681a0
Demonstrate these symbols/APIs:
  - google.golang.org/genproto/googleapis/rpc/errdetails.BadRequest

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:e45e2019da13d60f513be07a2a6683983e2963527a76346f1adb967dd6868b50","contract":["errdetails.BadRequest.GetFieldViolations returns nil on nil or empty BadRequest message","errdetails.BadRequest initializes with FieldViolations and returns them via GetFieldViolations","errdetails.BadRequest_FieldViolation provides field path and description strings via GetField and GetDescription","errdetails.BadRequest serializes and deserializes accurately with proto.Marshal and proto.Unmarshal preserving field violations","errdetails.BadRequest.Reset clears all field violations from the message"],"goal":"verify google.golang.org/genproto/googleapis/rpc/errdetails.BadRequest in pkg:golang/google.golang.org/genproto/googleapis/rpc@v0.0.0-20250728155136-f173205681a0","kind":"HOW","packages":["pkg:golang/google.golang.org/genproto/googleapis/rpc@v0.0.0-20250728155136-f173205681a0"],"schemaVersion":1,"symbols":["google.golang.org/genproto/googleapis/rpc/errdetails.BadRequest"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/google.golang.org/genproto/googleapis/rpc@v0.0.0-20250728155136-f173205681a0"],"schemaVersion":1,"subject":"pkg:golang/google.golang.org/genproto/googleapis/rpc@v0.0.0-20250728155136-f173205681a0","symbols":["google.golang.org/genproto/googleapis/rpc/errdetails.BadRequest"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require (
	google.golang.org/genproto/googleapis/rpc v0.0.0-20250728155136-f173205681a0
	google.golang.org/protobuf v1.36.12
)

github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
google.golang.org/genproto/googleapis/rpc v0.0.0-20250728155136-f173205681a0 h1:MAKi5q709QWfnkkpNQ0M12hYJ1+e8qYVDyowc4U1XZM=
google.golang.org/genproto/googleapis/rpc v0.0.0-20250728155136-f173205681a0/go.mod h1:qQ0YXyHHx3XkvlzUtpXDkS29lDSafHMZBAZDc03LQ3A=
google.golang.org/protobuf v1.36.12 h1:pJOKDDOyeXErUroCihFAd5LQuwXBSpVnKGrj5o/fwxc=
google.golang.org/protobuf v1.36.12/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=

package main

import (
	"fmt"

	"google.golang.org/genproto/googleapis/rpc/errdetails"
	"google.golang.org/protobuf/proto"
)

func main() {
	badRequest := &errdetails.BadRequest{
		FieldViolations: []*errdetails.BadRequest_FieldViolation{
			{
				Field:       "username",
				Description: "username is already taken",
			},
			{
				Field:       "email",
				Description: "invalid email format",
			},
		},
	}

	for _, v := range badRequest.GetFieldViolations() {
		fmt.Printf("violation: %s -> %s\n", v.GetField(), v.GetDescription())
	}

	bytes, err := proto.Marshal(badRequest)
	if err != nil {
		panic(err)
	}

	var parsed errdetails.BadRequest
	if err := proto.Unmarshal(bytes, &parsed); err != nil {
		panic(err)
	}
	fmt.Printf("unmarshaled %d violations\n", len(parsed.GetFieldViolations()))

	badRequest.Reset()
	fmt.Printf("after reset: %d violations\n", len(badRequest.GetFieldViolations()))
}

{
  "schemaVersion": 1,
  "goal": "verify google.golang.org/genproto/googleapis/rpc/errdetails.BadRequest in pkg:golang/google.golang.org/genproto/googleapis/rpc@v0.0.0-20250728155136-f173205681a0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/google.golang.org/genproto/googleapis/rpc@v0.0.0-20250728155136-f173205681a0"
  ],
  "symbols": [
    "google.golang.org/genproto/googleapis/rpc/errdetails.BadRequest"
  ]
}

package main

import (
	"fmt"
	"os"

	"google.golang.org/genproto/googleapis/rpc/errdetails"
	"google.golang.org/protobuf/proto"
)

func main() {
	// 1. Nil BadRequest returns nil
	var nilReq *errdetails.BadRequest
	if got := nilReq.GetFieldViolations(); got != nil {
		fmt.Fprintf(os.Stderr, "assertion failed: expected nilReq.GetFieldViolations() == nil, got %v\n", got)
		os.Exit(1)
	}

	// Empty BadRequest returns nil
	emptyReq := &errdetails.BadRequest{}
	if got := emptyReq.GetFieldViolations(); got != nil {
		fmt.Fprintf(os.Stderr, "assertion failed: expected emptyReq.GetFieldViolations() == nil, got %v\n", got)
		os.Exit(1)
	}

	// 2. Populated BadRequest with FieldViolations
	v1 := &errdetails.BadRequest_FieldViolation{
		Field:       "username",
		Description: "username is already taken",
	}
	v2 := &errdetails.BadRequest_FieldViolation{
		Field:       "email",
		Description: "invalid email format",
	}
	req := &errdetails.BadRequest{
		FieldViolations: []*errdetails.BadRequest_FieldViolation{v1, v2},
	}

	violations := req.GetFieldViolations()
	if len(violations) != 2 {
		fmt.Fprintf(os.Stderr, "assertion failed: expected 2 violations, got %d\n", len(violations))
		os.Exit(1)
	}

	// 3. FieldViolation getters
	if req.GetFieldViolations()[0].GetField() != "username" || req.GetFieldViolations()[0].GetDescription() != "username is already taken" {
		fmt.Fprintf(os.Stderr, "assertion failed: violation 0 mismatch\n")
		os.Exit(1)
	}
	if req.GetFieldViolations()[1].GetField() != "email" || req.GetFieldViolations()[1].GetDescription() != "invalid email format" {
		fmt.Fprintf(os.Stderr, "assertion failed: violation 1 mismatch\n")
		os.Exit(1)
	}

	var nilViolation *errdetails.BadRequest_FieldViolation
	if nilViolation.GetField() != "" || nilViolation.GetDescription() != "" {
		fmt.Fprintf(os.Stderr, "assertion failed: nilViolation getters should return empty strings\n")
		os.Exit(1)
	}

	// 4. Proto Marshal / Unmarshal
	data, err := proto.Marshal(req)
	if err != nil {
		fmt.Fprintf(os.Stderr, "assertion failed: proto.Marshal failed: %v\n", err)
		os.Exit(1)
	}

	var unmarshaled errdetails.BadRequest
	if err := proto.Unmarshal(data, &unmarshaled); err != nil {
		fmt.Fprintf(os.Stderr, "assertion failed: proto.Unmarshal failed: %v\n", err)
		os.Exit(1)
	}

	if len(unmarshaled.GetFieldViolations()) != 2 {
		fmt.Fprintf(os.Stderr, "assertion failed: expected 2 unmarshaled violations, got %d\n", len(unmarshaled.GetFieldViolations()))
		os.Exit(1)
	}
	if unmarshaled.GetFieldViolations()[0].GetField() != "username" || unmarshaled.GetFieldViolations()[1].GetField() != "email" {
		fmt.Fprintf(os.Stderr, "assertion failed: unmarshaled violation content mismatch\n")
		os.Exit(1)
	}

	// 5. Reset clears field violations
	req.Reset()
	if got := req.GetFieldViolations(); got != nil {
		fmt.Fprintf(os.Stderr, "assertion failed: expected nil after Reset(), got %v\n", got)
		os.Exit(1)
	}

	fmt.Println("All contract assertions passed.")
}