github.com/jackc/pgproto3/v2 v2.1.1: AuthenticationOk

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 github.com/jackc/pgproto3/v2.AuthenticationOk in pkg:golang/github.com/jackc/pgproto3/v2@v2.1.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/jackc/pgproto3/v2@v2.1.1
Demonstrate these symbols/APIs:
  - github.com/jackc/pgproto3/v2.AuthenticationOk

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:eb863c5605f72d28e7ce7a59eb5439381c6cb215920365b97edc76f239d3ee50","contract":["AuthenticationOk.Encode encodes backend authentication success message into wire format with message type identifier 'R', length 8, and AuthTypeOk","AuthenticationOk.Decode decodes wire message body into AuthenticationOk struct","AuthenticationOk.Decode rejects invalid body length or incorrect auth type","AuthenticationOk.MarshalJSON serializes to JSON object with Type AuthenticationOK","AuthenticationOk implements BackendMessage and AuthenticationResponseMessage interfaces","pgproto3.Frontend and pgproto3.Backend exchange AuthenticationOk over client and server streams"],"goal":"verify github.com/jackc/pgproto3/v2.AuthenticationOk in pkg:golang/github.com/jackc/pgproto3/v2@v2.1.1","kind":"HOW","packages":["pkg:golang/github.com/jackc/pgproto3/v2@v2.1.1"],"schemaVersion":1,"symbols":["github.com/jackc/pgproto3/v2.AuthenticationOk"]},"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/github.com/jackc/pgproto3/v2@v2.1.1"],"schemaVersion":1,"subject":"pkg:golang/github.com/jackc/pgproto3/v2@v2.1.1","symbols":["github.com/jackc/pgproto3/v2.AuthenticationOk"],"verifierAdapter":"golang@1"}

module example.com/authenticationok

go 1.22

require github.com/jackc/pgproto3/v2 v2.1.1

require (
	github.com/jackc/chunkreader/v2 v2.0.0 // indirect
	github.com/jackc/pgio v1.0.0 // indirect
)

github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/jackc/chunkreader/v2 v2.0.0 h1:DUwgMQuuPnS0rhMXenUtZpqZqrR/30NWY+qQvTpSvEs=
github.com/jackc/chunkreader/v2 v2.0.0/go.mod h1:odVSm741yZoC3dpHEUXIqA9tQRhFrgOHwnPIn9lDKlk=
github.com/jackc/pgio v1.0.0 h1:g12B9UwVnzGhueNavwioyEEpAmqMe1E/BN9ES+8ovkE=
github.com/jackc/pgio v1.0.0/go.mod h1:oP+2QK2wFfUWgr+gxjoBH9KGBb31Eio69xUb0w5bYf8=
github.com/jackc/pgproto3/v2 v2.1.1 h1:7PQ/4gLoqnl87ZxL7xjO0DR5gYuviDCZxQJsUlFW1eI=
github.com/jackc/pgproto3/v2 v2.1.1/go.mod h1:WfJCnwN3HIg9Ish/j3sgWXnAfK8A9Y0bwXYU5xKaEdA=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

package main

import (
	"fmt"

	"github.com/jackc/pgproto3/v2"
)

func main() {
	authOk := &pgproto3.AuthenticationOk{}
	buf := authOk.Encode(nil)

	var decoded pgproto3.AuthenticationOk
	if err := decoded.Decode(buf[5:]); err != nil {
		fmt.Printf("Decode error: %v\n", err)
		return
	}

	jsonBytes, err := decoded.MarshalJSON()
	if err != nil {
		fmt.Printf("MarshalJSON error: %v\n", err)
		return
	}

	fmt.Printf("AuthenticationOk encoded %d bytes: %s\n", len(buf), string(jsonBytes))
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/jackc/pgproto3/v2.AuthenticationOk in pkg:golang/github.com/jackc/pgproto3/v2@v2.1.1",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/jackc/pgproto3/v2@v2.1.1"
  ],
  "symbols": [
    "github.com/jackc/pgproto3/v2.AuthenticationOk"
  ]
}

package main

import (
	"bytes"
	"encoding/binary"
	"fmt"
	"os"

	"github.com/jackc/pgproto3/v2"
)

func main() {
	// 1. AuthenticationOk.Encode encodes backend authentication success message into wire format with message type identifier 'R', length 8, and AuthTypeOk
	{
		auth := &pgproto3.AuthenticationOk{}
		buf := auth.Encode(nil)
		if len(buf) != 9 {
			fmt.Fprintf(os.Stderr, "Contract 1 failed: expected 9 bytes, got %d\n", len(buf))
			os.Exit(1)
		}
		if buf[0] != 'R' {
			fmt.Fprintf(os.Stderr, "Contract 1 failed: expected type identifier 'R', got %c\n", buf[0])
			os.Exit(1)
		}
		msgLen := binary.BigEndian.Uint32(buf[1:5])
		if msgLen != 8 {
			fmt.Fprintf(os.Stderr, "Contract 1 failed: expected message length 8, got %d\n", msgLen)
			os.Exit(1)
		}
		authType := binary.BigEndian.Uint32(buf[5:9])
		if authType != 0 {
			fmt.Fprintf(os.Stderr, "Contract 1 failed: expected AuthTypeOk (0), got %d\n", authType)
			os.Exit(1)
		}
	}

	// 2. AuthenticationOk.Decode decodes wire message body into AuthenticationOk struct
	{
		auth := &pgproto3.AuthenticationOk{}
		buf := auth.Encode(nil)
		var decoded pgproto3.AuthenticationOk
		if err := decoded.Decode(buf[5:]); err != nil {
			fmt.Fprintf(os.Stderr, "Contract 2 failed Decode: %v\n", err)
			os.Exit(1)
		}
	}

	// 3. AuthenticationOk.Decode rejects invalid body length or incorrect auth type
	{
		var decoded pgproto3.AuthenticationOk
		if err := decoded.Decode([]byte{0, 0, 0}); err == nil {
			fmt.Fprintf(os.Stderr, "Contract 3 failed: expected error on 3 bytes body\n")
			os.Exit(1)
		}
		if err := decoded.Decode([]byte{0, 0, 0, 0, 0}); err == nil {
			fmt.Fprintf(os.Stderr, "Contract 3 failed: expected error on 5 bytes body\n")
			os.Exit(1)
		}
		badAuthPayload := make([]byte, 4)
		binary.BigEndian.PutUint32(badAuthPayload, 1)
		if err := decoded.Decode(badAuthPayload); err == nil {
			fmt.Fprintf(os.Stderr, "Contract 3 failed: expected error on non-zero auth type\n")
			os.Exit(1)
		}
	}

	// 4. AuthenticationOk.MarshalJSON serializes to JSON object with Type AuthenticationOK
	{
		auth := pgproto3.AuthenticationOk{}
		data, err := auth.MarshalJSON()
		if err != nil {
			fmt.Fprintf(os.Stderr, "Contract 4 failed MarshalJSON: %v\n", err)
			os.Exit(1)
		}
		expectedJSON := `{"Type":"AuthenticationOK"}`
		if string(data) != expectedJSON {
			fmt.Fprintf(os.Stderr, "Contract 4 failed: expected %s, got %s\n", expectedJSON, string(data))
			os.Exit(1)
		}
	}

	// 5. AuthenticationOk implements BackendMessage and AuthenticationResponseMessage interfaces
	{
		var (
			_ pgproto3.BackendMessage                = (*pgproto3.AuthenticationOk)(nil)
			_ pgproto3.AuthenticationResponseMessage = (*pgproto3.AuthenticationOk)(nil)
		)
		auth := &pgproto3.AuthenticationOk{}
		auth.Backend()
		auth.AuthenticationResponse()
	}

	// 6. pgproto3.Frontend and pgproto3.Backend exchange AuthenticationOk over client and server streams
	{
		clientToServer := &bytes.Buffer{}
		serverToClient := &bytes.Buffer{}

		frontend := pgproto3.NewFrontend(pgproto3.NewChunkReader(serverToClient), clientToServer)
		backend := pgproto3.NewBackend(pgproto3.NewChunkReader(clientToServer), serverToClient)

		if err := backend.Send(&pgproto3.AuthenticationOk{}); err != nil {
			fmt.Fprintf(os.Stderr, "Contract 6 failed backend.Send: %v\n", err)
			os.Exit(1)
		}

		msg, err := frontend.Receive()
		if err != nil {
			fmt.Fprintf(os.Stderr, "Contract 6 failed frontend.Receive: %v\n", err)
			os.Exit(1)
		}

		if _, ok := msg.(*pgproto3.AuthenticationOk); !ok {
			fmt.Fprintf(os.Stderr, "Contract 6 failed: expected *pgproto3.AuthenticationOk, got %T\n", msg)
			os.Exit(1)
		}
	}

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