github.com/jackc/pgx/v5 v5.10.0: Parse connection pool configuration using pgxpool.ParseConfig

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: Parse connection pool configuration using pgxpool.ParseConfig
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/jackc/pgx/v5@v5.10.0
Demonstrate these symbols/APIs:
  - pgxpool.ParseConfig
Constraints:
  - executionContext: node
Required runtime conditions:
  - ecosystem: npm
  - language: javascript
  - moduleSystem: cjs
  - packageManager: npm@11.8.0
  - runtime: node@24.13.1

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:sha256:68012e5883236dd40d2e910a144989dd92151fd8610e08340589141f1a7c89fb","contract":["pgxpool.ParseConfig parses valid PostgreSQL connection URI into pool Config","pgxpool.ParseConfig populates underlying ConnConfig host, port, database, user, and password","pgxpool.ParseConfig parses pool parameters including max and min connections and timeouts","pgxpool.ParseConfig returns an error for invalid connection strings"],"goal":"Parse connection pool configuration using pgxpool.ParseConfig","kind":"HOW","packages":["pkg:golang/github.com/jackc/pgx/v5@v5.10.0"],"schemaVersion":1,"symbols":["pgxpool.ParseConfig"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","ecosystem":"golang","os":"windows","osVersionBucket":"11","packageManager":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/github.com/jackc/pgx/v5@v5.10.0"],"schemaVersion":1,"symbols":["pgxpool.ParseConfig"],"verifierAdapter":"golang@1"}

module sample

go 1.26.5

require github.com/jackc/pgx/v5 v5.10.0

require (
	github.com/jackc/pgpassfile v1.0.0 // indirect
	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
	github.com/jackc/puddle/v2 v2.2.2 // indirect
	golang.org/x/sync v0.17.0 // indirect
	golang.org/x/text v0.29.0 // indirect
)

github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/jackc/pgpassfile v1.0.0 h1:/6Hmqy13Ss2zCq62VdNG8tM1wchn8zjSGOBJ6icpsIM=
github.com/jackc/pgpassfile v1.0.0/go.mod h1:CEx0iS5ambNFdcRtxPj5JhEz+xB6uRky5eyVu/W2HEg=
github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 h1:iCEnooe7UlwOQYpKFhBabPMi4aNAfoODPEFNiAnClxo=
github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761/go.mod h1:5TJZWKEWniPve33vlWYSoGYefn3gLQRzjfDlhSJ9ZKM=
github.com/jackc/pgx/v5 v5.10.0 h1:VhSvgU2jSli8o3AqIEOTJr7rZwAEUVo4E4XhR94Zfr0=
github.com/jackc/pgx/v5 v5.10.0/go.mod h1:mal1tBGAFfLHvZzaYh77YS/eC6IX9OWbRV1QIIM0Jn4=
github.com/jackc/puddle/v2 v2.2.2 h1:PR8nw+E/1w0GLuRFSmiioY6UooMp6KJv0/61nB7icHo=
github.com/jackc/puddle/v2 v2.2.2/go.mod h1:vriiEXHvEE654aYKXXjOvZM39qJ0q+azkZFrfEOc3H4=
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 v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
golang.org/x/sync v0.17.0 h1:l60nONMj9l5drqw6jlhIELNv9I0A4OFgRsG9k2oT9Ug=
golang.org/x/sync v0.17.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
golang.org/x/text v0.29.0 h1:1neNs90w9YzJ9BocxfsQNHKuAT4pkghyXc4nhZ6sJvk=
golang.org/x/text v0.29.0/go.mod h1:7MhJOA9CD2qZyOKYazxdYMF85OwPdEr9jTtBpO7ydH4=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

package main

import (
	"fmt"
	"log"

	"github.com/jackc/pgx/v5/pgxpool"
)

func main() {
	connStr := "postgres://sampleuser:securepwd123@localhost:5432/sampledb?pool_max_conns=10&pool_min_conns=2&pool_max_conn_lifetime=1h&pool_max_conn_idle_time=30m"
	config, err := pgxpool.ParseConfig(connStr)
	if err != nil {
		log.Fatalf("failed to parse pool config: %v", err)
	}

	fmt.Printf("Host: %s\n", config.ConnConfig.Host)
	fmt.Printf("Port: %d\n", config.ConnConfig.Port)
	fmt.Printf("Database: %s\n", config.ConnConfig.Database)
	fmt.Printf("User: %s\n", config.ConnConfig.User)
	fmt.Printf("MaxConns: %d\n", config.MaxConns)
	fmt.Printf("MinConns: %d\n", config.MinConns)
	fmt.Printf("MaxConnLifetime: %v\n", config.MaxConnLifetime)
	fmt.Printf("MaxConnIdleTime: %v\n", config.MaxConnIdleTime)
}

{
  "schemaVersion": 1,
  "goal": "Parse connection pool configuration using pgxpool.ParseConfig",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/jackc/pgx/v5@v5.10.0"
  ],
  "symbols": [
    "pgxpool.ParseConfig"
  ]
}

package main

import (
	"fmt"
	"os"
	"time"

	"github.com/jackc/pgx/v5/pgxpool"
)

func main() {
	// Assertion 1: Parse valid PostgreSQL connection string into pool Config
	connStr := "postgres://sampleuser:securepwd123@localhost:5432/sampledb?pool_max_conns=10&pool_min_conns=2&pool_max_conn_lifetime=1h&pool_max_conn_idle_time=30m"
	config, err := pgxpool.ParseConfig(connStr)
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: pgxpool.ParseConfig returned error: %v\n", err)
		os.Exit(1)
	}

	// Assertion 2: Verify parsed underlying ConnConfig properties
	if config.ConnConfig.Host != "localhost" {
		fmt.Fprintf(os.Stderr, "FAIL: expected host 'localhost', got '%s'\n", config.ConnConfig.Host)
		os.Exit(1)
	}
	if config.ConnConfig.Port != 5432 {
		fmt.Fprintf(os.Stderr, "FAIL: expected port 5432, got %d\n", config.ConnConfig.Port)
		os.Exit(1)
	}
	if config.ConnConfig.User != "sampleuser" {
		fmt.Fprintf(os.Stderr, "FAIL: expected user 'sampleuser', got '%s'\n", config.ConnConfig.User)
		os.Exit(1)
	}
	if config.ConnConfig.Password != "securepwd123" {
		fmt.Fprintf(os.Stderr, "FAIL: expected password 'securepwd123', got '%s'\n", config.ConnConfig.Password)
		os.Exit(1)
	}
	if config.ConnConfig.Database != "sampledb" {
		fmt.Fprintf(os.Stderr, "FAIL: expected database 'sampledb', got '%s'\n", config.ConnConfig.Database)
		os.Exit(1)
	}

	// Assertion 3: Verify parsed pool configuration parameters
	if config.MaxConns != 10 {
		fmt.Fprintf(os.Stderr, "FAIL: expected MaxConns 10, got %d\n", config.MaxConns)
		os.Exit(1)
	}
	if config.MinConns != 2 {
		fmt.Fprintf(os.Stderr, "FAIL: expected MinConns 2, got %d\n", config.MinConns)
		os.Exit(1)
	}
	if config.MaxConnLifetime != time.Hour {
		fmt.Fprintf(os.Stderr, "FAIL: expected MaxConnLifetime %v, got %v\n", time.Hour, config.MaxConnLifetime)
		os.Exit(1)
	}
	if config.MaxConnIdleTime != 30*time.Minute {
		fmt.Fprintf(os.Stderr, "FAIL: expected MaxConnIdleTime %v, got %v\n", 30*time.Minute, config.MaxConnIdleTime)
		os.Exit(1)
	}

	// Assertion 4: Parse invalid connection string returns error
	invalidConnStr := "://invalid uri string"
	_, err = pgxpool.ParseConfig(invalidConnStr)
	if err == nil {
		fmt.Fprintf(os.Stderr, "FAIL: expected error for invalid connection string, got nil\n")
		os.Exit(1)
	}

	fmt.Println("PASS: all contract assertions passed for pkg:golang/github.com/jackc/pgx/v5@v5.10.0")
}