github.com/jackc/pgx/v5 v5.7.4: pgx.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 pgx.ParseConfig in pkg:golang/github.com/jackc/pgx/v5@v5.7.4
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/jackc/pgx/v5@v5.7.4
Demonstrate these symbols/APIs:
  - pgx.ParseConfig

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:sha256:30f3969d38f7ea0d6033a1de07a5e247604a7a0e3f4b14b19d24fa24101fd588","contract":["pgx.ParseConfig parses standard PostgreSQL connection URI into ConnConfig","pgx.ParseConfig correctly extracts Host, Port, User, Password, and Database fields","pgx.ParseConfig parses query parameters into RuntimeParams","pgx.ParseConfig handles pgx v5 specific query execution mode and cache capacities","ParseDatabaseURL helper returns same configuration","ConnConfig.Copy produces an independent copy of configuration","pgx.ParseConfig returns error for invalid connection URI format"],"goal":"verify pgx.ParseConfig in pkg:golang/github.com/jackc/pgx/v5@v5.7.4","kind":"HOW","packages":["pkg:golang/github.com/jackc/pgx/v5@v5.7.4"],"schemaVersion":1,"symbols":["pgx.ParseConfig"]},"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/pgx/v5@v5.7.4"],"schemaVersion":1,"subject":"pkg:golang/github.com/jackc/pgx/v5@v5.7.4","symbols":["pgx.ParseConfig"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require github.com/jackc/pgx/v5 v5.7.4

require (
	github.com/jackc/pgpassfile v1.0.0 // indirect
	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
	golang.org/x/crypto v0.31.0 // indirect
	golang.org/x/text v0.21.0 // 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 v5.7.4 h1:9wKznZrhWa2QiHL+NjTSPP6yjl3451BX3imWDnokYlg=
github.com/jackc/pgx/v5 v5.7.4/go.mod h1:ncY89UGWxg82EykZUwSpUKEfccBGGYq1xjrOpsbsfGQ=
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 v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKsk=
github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
golang.org/x/crypto v0.31.0 h1:ihbySMvVjLAeSH1IbfcRTkD/iNscyz8rGzjF/E5hV6U=
golang.org/x/crypto v0.31.0/go.mod h1:kDsLvtWBEx7MV9tJOj9bnXsPbxwJQ6csT/x4KIN4Ssk=
golang.org/x/sync v0.10.0 h1:3NQrjDixjgGwUOCaF8w2+VYHv0Ve/vGYSbdkTa98gmQ=
golang.org/x/sync v0.10.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
golang.org/x/text v0.21.0 h1:zyQAAkrwaneQ066sspRyJaG9VNi/YJ1NfzcGB3hZ/qo=
golang.org/x/text v0.21.0/go.mod h1:4IBbMaMmOPCJ8SecivzSH54+73PCFmPWxNTLm+vZkEQ=
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"

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

// ParseDatabaseURL parses a PostgreSQL connection URI string into a pgx.ConnConfig.
func ParseDatabaseURL(uri string) (*pgx.ConnConfig, error) {
	config, err := pgx.ParseConfig(uri)
	if err != nil {
		return nil, fmt.Errorf("failed to parse connection config: %w", err)
	}
	return config, nil
}

{
  "schemaVersion": 1,
  "goal": "verify pgx.ParseConfig in pkg:golang/github.com/jackc/pgx/v5@v5.7.4",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/jackc/pgx/v5@v5.7.4"
  ],
  "symbols": [
    "pgx.ParseConfig"
  ]
}

package main

import (
	"fmt"
	"os"

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

func main() {
	connStr := "postgres://alice:secretpass@localhost:5432/testdb?sslmode=disable&application_name=sampleapp"

	// Assertion 1: pgx.ParseConfig parses standard PostgreSQL connection URI into ConnConfig
	config, err := pgx.ParseConfig(connStr)
	if err != nil {
		fmt.Fprintf(os.Stderr, "unexpected error parsing valid URI: %v\n", err)
		os.Exit(1)
	}
	if config == nil {
		fmt.Fprintf(os.Stderr, "expected non-nil config\n")
		os.Exit(1)
	}

	// Assertion 2: pgx.ParseConfig correctly extracts Host, Port, User, Password, and Database fields
	if config.Host != "localhost" {
		fmt.Fprintf(os.Stderr, "expected Host 'localhost', got %q\n", config.Host)
		os.Exit(1)
	}
	if config.Port != 5432 {
		fmt.Fprintf(os.Stderr, "expected Port 5432, got %d\n", config.Port)
		os.Exit(1)
	}
	if config.User != "alice" {
		fmt.Fprintf(os.Stderr, "expected User 'alice', got %q\n", config.User)
		os.Exit(1)
	}
	if config.Password != "secretpass" {
		fmt.Fprintf(os.Stderr, "expected Password 'secretpass', got %q\n", config.Password)
		os.Exit(1)
	}
	if config.Database != "testdb" {
		fmt.Fprintf(os.Stderr, "expected Database 'testdb', got %q\n", config.Database)
		os.Exit(1)
	}

	// Assertion 3: pgx.ParseConfig parses query parameters into RuntimeParams
	if config.RuntimeParams == nil || config.RuntimeParams["application_name"] != "sampleapp" {
		fmt.Fprintf(os.Stderr, "expected RuntimeParams['application_name'] to be 'sampleapp', got %v\n", config.RuntimeParams)
		os.Exit(1)
	}

	// Assertion 4: pgx.ParseConfig handles pgx v5 specific query execution mode and cache capacities
	customConnStr := "postgres://alice:secretpass@localhost:5432/testdb?default_query_exec_mode=simple_protocol&statement_cache_capacity=256&description_cache_capacity=128"
	customConfig, err := pgx.ParseConfig(customConnStr)
	if err != nil {
		fmt.Fprintf(os.Stderr, "unexpected error parsing custom config: %v\n", err)
		os.Exit(1)
	}
	if customConfig.DefaultQueryExecMode != pgx.QueryExecModeSimpleProtocol {
		fmt.Fprintf(os.Stderr, "expected DefaultQueryExecMode SimpleProtocol, got %v\n", customConfig.DefaultQueryExecMode)
		os.Exit(1)
	}
	if customConfig.StatementCacheCapacity != 256 {
		fmt.Fprintf(os.Stderr, "expected StatementCacheCapacity 256, got %d\n", customConfig.StatementCacheCapacity)
		os.Exit(1)
	}
	if customConfig.DescriptionCacheCapacity != 128 {
		fmt.Fprintf(os.Stderr, "expected DescriptionCacheCapacity 128, got %d\n", customConfig.DescriptionCacheCapacity)
		os.Exit(1)
	}

	// Assertion 5: ParseDatabaseURL helper returns same configuration
	helperConfig, err := sample.ParseDatabaseURL(connStr)
	if err != nil {
		fmt.Fprintf(os.Stderr, "unexpected error from ParseDatabaseURL: %v\n", err)
		os.Exit(1)
	}
	if helperConfig.Host != config.Host || helperConfig.Database != config.Database || helperConfig.User != config.User {
		fmt.Fprintf(os.Stderr, "helper returned inconsistent config\n")
		os.Exit(1)
	}

	// Assertion 6: ConnConfig.Copy produces an independent copy of configuration
	copiedConfig := config.Copy()
	copiedConfig.Database = "newdb"
	if config.Database == copiedConfig.Database {
		fmt.Fprintf(os.Stderr, "expected copied config to be independent from original\n")
		os.Exit(1)
	}

	// Assertion 7: pgx.ParseConfig returns error for invalid connection URI format
	invalidURI := "postgres://[invalid-host-format:999999"
	_, err = pgx.ParseConfig(invalidURI)
	if err == nil {
		fmt.Fprintf(os.Stderr, "expected error for invalid URI, got nil\n")
		os.Exit(1)
	}

	_, err = sample.ParseDatabaseURL(invalidURI)
	if err == nil {
		fmt.Fprintf(os.Stderr, "expected helper error for invalid URI, got nil\n")
		os.Exit(1)
	}

	fmt.Println("PASS: all pgx.ParseConfig contract assertions passed.")
}