github.com/jackc/pgservicefile v0.0.0-20200714003250-2b9c44734f2b: ReadServicefile

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/pgservicefile.ReadServicefile in pkg:golang/github.com/jackc/pgservicefile@v0.0.0-20200714003250-2b9c44734f2b
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/jackc/pgservicefile@v0.0.0-20200714003250-2b9c44734f2b
Demonstrate these symbols/APIs:
  - github.com/jackc/pgservicefile.ReadServicefile

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:af1c8d736da94eb9066e0243cd7575966dac15b2287b8ce5d0025c4f246edce3","contract":["pgservicefile.ReadServicefile reads and parses a PostgreSQL service file into a Servicefile","pgservicefile.ReadServicefile extracts section names and key-value configuration parameters","pgservicefile.ReadServicefile handles multiple service sections, comments, and empty lines","pgservicefile.ReadServicefile returns an error when the specified file does not exist","pgservicefile.ReadServicefile returns syntax errors for malformed service file lines"],"goal":"verify github.com/jackc/pgservicefile.ReadServicefile in pkg:golang/github.com/jackc/pgservicefile@v0.0.0-20200714003250-2b9c44734f2b","kind":"HOW","packages":["pkg:golang/github.com/jackc/pgservicefile@v0.0.0-20200714003250-2b9c44734f2b"],"schemaVersion":1,"symbols":["github.com/jackc/pgservicefile.ReadServicefile"]},"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/pgservicefile@v0.0.0-20200714003250-2b9c44734f2b"],"schemaVersion":1,"subject":"pkg:golang/github.com/jackc/pgservicefile@v0.0.0-20200714003250-2b9c44734f2b","symbols":["github.com/jackc/pgservicefile.ReadServicefile"],"verifierAdapter":"golang@1"}

module sample

go 1.22

require github.com/jackc/pgservicefile v0.0.0-20200714003250-2b9c44734f2b

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/pgservicefile v0.0.0-20200714003250-2b9c44734f2b h1:C8S2+VttkHFdOOCXJe+YGfa4vHYwlt4Zx+IVXQ97jYg=
github.com/jackc/pgservicefile v0.0.0-20200714003250-2b9c44734f2b/go.mod h1:vsD4gTJCa9TptPL8sPkXrLZ+hDuNrZCnj29CQpr4X1E=
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 v1.5.1 h1:nOGnQDM7FYENwehXlg/kFVnos3rEvtKTjRvOWSzb6H4=
github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
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=

{
  "schemaVersion": 1,
  "goal": "verify github.com/jackc/pgservicefile.ReadServicefile in pkg:golang/github.com/jackc/pgservicefile@v0.0.0-20200714003250-2b9c44734f2b",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/jackc/pgservicefile@v0.0.0-20200714003250-2b9c44734f2b"
  ],
  "symbols": [
    "github.com/jackc/pgservicefile.ReadServicefile"
  ]
}

package main

import (
	"fmt"
	"os"
	"path/filepath"

	"github.com/jackc/pgservicefile"
)

func main() {
	tmpDir, err := os.MkdirTemp("", "pgservicefile-contract-*")
	if err != nil {
		fmt.Fprintf(os.Stderr, "failed to create temp dir: %v\n", err)
		os.Exit(1)
	}
	defer os.RemoveAll(tmpDir)

	// 1. Verify ReadServicefile reads and parses a PostgreSQL service file into a Servicefile
	content := `# PostgreSQL service configuration
[db_main]
host=localhost
port=5432
user=dbuser
dbname=production

[db_replica]
host=replica.example.com
port=5433
user=readonly
dbname=production
`
	validFile := filepath.Join(tmpDir, "pg_service.conf")
	if err := os.WriteFile(validFile, []byte(content), 0600); err != nil {
		fmt.Fprintf(os.Stderr, "failed to write valid service file: %v\n", err)
		os.Exit(1)
	}

	sf, err := pgservicefile.ReadServicefile(validFile)
	if err != nil {
		fmt.Fprintf(os.Stderr, "ReadServicefile failed: %v\n", err)
		os.Exit(1)
	}
	if sf == nil {
		fmt.Fprintf(os.Stderr, "expected non-nil Servicefile\n")
		os.Exit(1)
	}
	if len(sf.Services) != 2 {
		fmt.Fprintf(os.Stderr, "expected 2 services, got %d\n", len(sf.Services))
		os.Exit(1)
	}

	// 2. Verify ReadServicefile extracts section names and key-value configuration parameters
	svcMain, err := sf.GetService("db_main")
	if err != nil {
		fmt.Fprintf(os.Stderr, "GetService('db_main') failed: %v\n", err)
		os.Exit(1)
	}
	if svcMain.Name != "db_main" {
		fmt.Fprintf(os.Stderr, "expected service name 'db_main', got %s\n", svcMain.Name)
		os.Exit(1)
	}
	if svcMain.Settings["host"] != "localhost" ||
		svcMain.Settings["port"] != "5432" ||
		svcMain.Settings["user"] != "dbuser" ||
		svcMain.Settings["dbname"] != "production" {
		fmt.Fprintf(os.Stderr, "service settings mismatch: %+v\n", svcMain.Settings)
		os.Exit(1)
	}

	// 3. Verify ReadServicefile handles multiple service sections, comments, and empty lines
	svcReplica, err := sf.GetService("db_replica")
	if err != nil {
		fmt.Fprintf(os.Stderr, "GetService('db_replica') failed: %v\n", err)
		os.Exit(1)
	}
	if svcReplica.Name != "db_replica" {
		fmt.Fprintf(os.Stderr, "expected service name 'db_replica', got %s\n", svcReplica.Name)
		os.Exit(1)
	}
	if svcReplica.Settings["host"] != "replica.example.com" ||
		svcReplica.Settings["port"] != "5433" ||
		svcReplica.Settings["user"] != "readonly" ||
		svcReplica.Settings["dbname"] != "production" {
		fmt.Fprintf(os.Stderr, "replica settings mismatch: %+v\n", svcReplica.Settings)
		os.Exit(1)
	}

	// 4. Verify ReadServicefile returns an error when the specified file does not exist
	nonExistentFile := filepath.Join(tmpDir, "non_existent.conf")
	_, err = pgservicefile.ReadServicefile(nonExistentFile)
	if err == nil {
		fmt.Fprintf(os.Stderr, "expected error for non-existent file, got nil\n")
		os.Exit(1)
	}

	// 5. Verify ReadServicefile returns syntax errors for malformed service file lines
	malformedContent := "malformed line without section header\n"
	malformedFile := filepath.Join(tmpDir, "malformed.conf")
	if err := os.WriteFile(malformedFile, []byte(malformedContent), 0600); err != nil {
		fmt.Fprintf(os.Stderr, "failed to write malformed service file: %v\n", err)
		os.Exit(1)
	}

	_, err = pgservicefile.ReadServicefile(malformedFile)
	if err == nil {
		fmt.Fprintf(os.Stderr, "expected syntax error for malformed file, got nil\n")
		os.Exit(1)
	}

	fmt.Println("pgservicefile ReadServicefile contract verified successfully")
}