github.com/jackc/pgx/v5 v5.10.0: 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: verify github.com/jackc/pgx/v5.ParseConfig in pkg:golang/github.com/jackc/pgx/v5@v5.10.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/jackc/pgx/v5@v5.10.0
Demonstrate these symbols/APIs:
  - github.com/jackc/pgx/v5.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:sha256:21c75c0ba96371b83ea07c0fce633669008a5f91a64aac5ebe9c8cdb1ff2a2f2","contract":["pgx.ParseConfig parses PostgreSQL connection URL and extracts host, port, database, user, password, and runtime parameters","pgx.ParseConfig parses libpq key-value connection string and sets connect timeout","pgx.ParseConfig returns ConnConfig with parsed connection options","pgx.ParseConfig returns error when connection string format is invalid"],"goal":"verify github.com/jackc/pgx/v5.ParseConfig in pkg:golang/github.com/jackc/pgx/v5@v5.10.0","kind":"HOW","packages":["pkg:golang/github.com/jackc/pgx/v5@v5.10.0"],"schemaVersion":1,"symbols":["github.com/jackc/pgx/v5.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":["github.com/jackc/pgx/v5.ParseConfig"],"verifierAdapter":"golang@1"}

module sample

go 1.25.0

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
	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 sample

import (
	"fmt"
	"time"

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

// ParsedConnectionSummary holds key connection parameters extracted from a pgx.ConnConfig.
type ParsedConnectionSummary struct {
	Host           string
	Port           uint16
	Database       string
	User           string
	Password       string
	ConnectTimeout time.Duration
	RuntimeParams  map[string]string
}

// ParseConnectionString parses a PostgreSQL DSN/URI string into a pgx.ConnConfig and extracts summary fields.
func ParseConnectionString(connString string) (*ParsedConnectionSummary, error) {
	cfg, err := pgx.ParseConfig(connString)
	if err != nil {
		return nil, fmt.Errorf("failed to parse connection string: %w", err)
	}

	summary := &ParsedConnectionSummary{
		Host:           cfg.Host,
		Port:           cfg.Port,
		Database:       cfg.Database,
		User:           cfg.User,
		Password:       cfg.Password,
		ConnectTimeout: cfg.ConnectTimeout,
		RuntimeParams:  make(map[string]string, len(cfg.RuntimeParams)),
	}

	for k, v := range cfg.RuntimeParams {
		summary.RuntimeParams[k] = v
	}

	return summary, nil
}

// BuildConnConfig parses a connection string and applies custom fallback configuration.
func BuildConnConfig(connString string, defaultTimeout time.Duration) (*pgx.ConnConfig, error) {
	cfg, err := pgx.ParseConfig(connString)
	if err != nil {
		return nil, fmt.Errorf("invalid connection string: %w", err)
	}

	if cfg.ConnectTimeout == 0 && defaultTimeout > 0 {
		cfg.ConnectTimeout = defaultTimeout
	}

	return cfg, nil
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/jackc/pgx/v5.ParseConfig in pkg:golang/github.com/jackc/pgx/v5@v5.10.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/jackc/pgx/v5@v5.10.0"
  ],
  "symbols": [
    "github.com/jackc/pgx/v5.ParseConfig"
  ],
  "constraints": {
    "executionContext": "node"
  },
  "runtimeConditions": {
    "ecosystem": "npm",
    "language": "javascript",
    "moduleSystem": "cjs",
    "packageManager": "npm@11.8.0",
    "runtime": "node@24.13.1"
  }
}

package main

import (
	"fmt"
	"os"
	"time"

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

func main() {
	// 1. Verify pgx.ParseConfig parses standard PostgreSQL URL
	urlDSN := "postgres://alice:secret123@localhost:5432/my_app_db?search_path=app,public"
	cfg, err := pgx.ParseConfig(urlDSN)
	if err != nil {
		fmt.Fprintf(os.Stderr, "ParseConfig(URL) failed: %v\n", err)
		os.Exit(1)
	}

	if cfg.Host != "localhost" {
		fmt.Fprintf(os.Stderr, "expected Host 'localhost', got %q\n", cfg.Host)
		os.Exit(1)
	}
	if cfg.Port != 5432 {
		fmt.Fprintf(os.Stderr, "expected Port 5432, got %d\n", cfg.Port)
		os.Exit(1)
	}
	if cfg.Database != "my_app_db" {
		fmt.Fprintf(os.Stderr, "expected Database 'my_app_db', got %q\n", cfg.Database)
		os.Exit(1)
	}
	if cfg.User != "alice" {
		fmt.Fprintf(os.Stderr, "expected User 'alice', got %q\n", cfg.User)
		os.Exit(1)
	}
	if cfg.Password != "secret123" {
		fmt.Fprintf(os.Stderr, "expected Password 'secret123', got %q\n", cfg.Password)
		os.Exit(1)
	}
	if cfg.RuntimeParams["search_path"] != "app,public" {
		fmt.Fprintf(os.Stderr, "expected search_path 'app,public', got %q\n", cfg.RuntimeParams["search_path"])
		os.Exit(1)
	}

	// 2. Verify pgx.ParseConfig parses libpq key-value connection string
	kvDSN := "host=127.0.0.1 port=5433 dbname=test_service user=bob password=pass connect_timeout=5"
	kvCfg, err := pgx.ParseConfig(kvDSN)
	if err != nil {
		fmt.Fprintf(os.Stderr, "ParseConfig(KV) failed: %v\n", err)
		os.Exit(1)
	}
	if kvCfg.Host != "127.0.0.1" || kvCfg.Port != 5433 || kvCfg.Database != "test_service" || kvCfg.User != "bob" {
		fmt.Fprintf(os.Stderr, "KV config fields mismatch: %+v\n", kvCfg)
		os.Exit(1)
	}
	if kvCfg.ConnectTimeout != 5*time.Second {
		fmt.Fprintf(os.Stderr, "expected ConnectTimeout 5s, got %v\n", kvCfg.ConnectTimeout)
		os.Exit(1)
	}

	// 3. Verify sample helper ParseConnectionString
	summary, err := sample.ParseConnectionString(urlDSN)
	if err != nil {
		fmt.Fprintf(os.Stderr, "sample.ParseConnectionString failed: %v\n", err)
		os.Exit(1)
	}
	if summary.Host != "localhost" || summary.Database != "my_app_db" || summary.User != "alice" {
		fmt.Fprintf(os.Stderr, "summary mismatch: %+v\n", summary)
		os.Exit(1)
	}
	if summary.RuntimeParams["search_path"] != "app,public" {
		fmt.Fprintf(os.Stderr, "summary search_path mismatch: %+v\n", summary.RuntimeParams)
		os.Exit(1)
	}

	// 4. Verify sample helper BuildConnConfig applies default timeout when not specified
	customCfg, err := sample.BuildConnConfig("postgres://user:pass@localhost:5432/db", 10*time.Second)
	if err != nil {
		fmt.Fprintf(os.Stderr, "sample.BuildConnConfig failed: %v\n", err)
		os.Exit(1)
	}
	if customCfg.ConnectTimeout != 10*time.Second {
		fmt.Fprintf(os.Stderr, "expected default timeout 10s applied, got %v\n", customCfg.ConnectTimeout)
		os.Exit(1)
	}

	// 5. Verify BuildConnConfig does not overwrite explicit timeout
	explicitTimeoutCfg, err := sample.BuildConnConfig(kvDSN, 10*time.Second)
	if err != nil {
		fmt.Fprintf(os.Stderr, "sample.BuildConnConfig with explicit timeout failed: %v\n", err)
		os.Exit(1)
	}
	if explicitTimeoutCfg.ConnectTimeout != 5*time.Second {
		fmt.Fprintf(os.Stderr, "expected explicit timeout 5s preserved, got %v\n", explicitTimeoutCfg.ConnectTimeout)
		os.Exit(1)
	}

	// 6. Verify pgx.ParseConfig returns error on invalid connection strings
	_, invalidErr := pgx.ParseConfig("://invalid-url-%%")
	if invalidErr == nil {
		fmt.Fprintf(os.Stderr, "expected error for invalid URL, got nil\n")
		os.Exit(1)
	}

	_, sampleInvalidErr := sample.ParseConnectionString("://invalid-url-%%")
	if sampleInvalidErr == nil {
		fmt.Fprintf(os.Stderr, "expected sample error for invalid URL, got nil\n")
		os.Exit(1)
	}

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