github.com/subosito/gotenv v1.6.0: Env

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/subosito/gotenv.Env in pkg:golang/github.com/subosito/gotenv@v1.6.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/subosito/gotenv@v1.6.0
Demonstrate these symbols/APIs:
  - github.com/subosito/gotenv.Env

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:sha256:90b18d373cc8f3ab56ba4974f98b2944d2df424069a4d395873dfbb6e3cf5c28","contract":["gotenv.Parse returns Env map with parsed key-value pairs","gotenv.Parse expands referenced variables in Env values","gotenv.Parse returns empty Env for empty reader input","gotenv.StrictParse returns Env and nil error for valid input","gotenv.StrictParse returns error for syntax error input"],"goal":"verify github.com/subosito/gotenv.Env in pkg:golang/github.com/subosito/gotenv@v1.6.0","kind":"HOW","packages":["pkg:golang/github.com/subosito/gotenv@v1.6.0"],"schemaVersion":1,"symbols":["github.com/subosito/gotenv.Env"]},"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/subosito/gotenv@v1.6.0"],"schemaVersion":1,"subject":"pkg:golang/github.com/subosito/gotenv@v1.6.0","symbols":["github.com/subosito/gotenv.Env"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.23

require github.com/subosito/gotenv v1.6.0

require golang.org/x/text v0.12.0 // indirect

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/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/testify v1.7.5 h1:s5PTfem8p8EbKQOctVV53k6jCJt3UX4IEJzwh+C324Q=
github.com/stretchr/testify v1.7.5/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
github.com/subosito/gotenv v1.6.0 h1:9NlTDc1FTs4qu0DDq7AEtTPNw6SVm7uBMsUCUjABIf8=
github.com/subosito/gotenv v1.6.0/go.mod h1:Dk4QP5c2W3ibzajGcXpNraDfq2IrhjMIvMSWPKKo0FU=
golang.org/x/text v0.12.0 h1:k+n5B8goJNdU7hSvEtMUz3d1Q6D/XW4COJSJR6fN0mc=
golang.org/x/text v0.12.0/go.mod h1:TvPlkZtksWOMsz7fbANvkp4WM8x/WCo/om8BMLbz+aE=
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"
	"strings"

	"github.com/subosito/gotenv"
)

func main() {
	input := "PORT=8080\nHOST=localhost\nAPP_NAME=sample-app\n"
	env := gotenv.Parse(strings.NewReader(input))

	fmt.Printf("Parsed %d environment variables:\n", len(env))
	fmt.Printf("PORT: %s\n", env["PORT"])
	fmt.Printf("HOST: %s\n", env["HOST"])
	fmt.Printf("APP_NAME: %s\n", env["APP_NAME"])
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/subosito/gotenv.Env in pkg:golang/github.com/subosito/gotenv@v1.6.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/subosito/gotenv@v1.6.0"
  ],
  "symbols": [
    "github.com/subosito/gotenv.Env"
  ]
}

package main

import (
	"fmt"
	"os"
	"strings"

	"github.com/subosito/gotenv"
)

func main() {
	// 1. gotenv.Parse returns Env map with parsed key-value pairs
	input1 := "FOO=bar\nBAZ=qux\n"
	env1 := gotenv.Parse(strings.NewReader(input1))
	var _ gotenv.Env = env1
	if env1["FOO"] != "bar" || env1["BAZ"] != "qux" {
		fmt.Fprintf(os.Stderr, "assertion 1 failed: expected FOO=bar, BAZ=qux, got %v\n", env1)
		os.Exit(1)
	}

	// 2. gotenv.Parse expands referenced variables in Env values
	input2 := "BASE=world\nMESSAGE=hello $BASE\n"
	env2 := gotenv.Parse(strings.NewReader(input2))
	if env2["MESSAGE"] != "hello world" {
		fmt.Fprintf(os.Stderr, "assertion 2 failed: expected 'hello world', got %q\n", env2["MESSAGE"])
		os.Exit(1)
	}

	// 3. gotenv.Parse returns empty Env for empty reader input
	env3 := gotenv.Parse(strings.NewReader(""))
	if len(env3) != 0 {
		fmt.Fprintf(os.Stderr, "assertion 3 failed: expected empty Env, got len=%d\n", len(env3))
		os.Exit(1)
	}

	// 4. gotenv.StrictParse returns Env and nil error for valid input
	input4 := "KEY=value\n"
	env4, err := gotenv.StrictParse(strings.NewReader(input4))
	if err != nil {
		fmt.Fprintf(os.Stderr, "assertion 4 failed: unexpected error: %v\n", err)
		os.Exit(1)
	}
	if env4["KEY"] != "value" {
		fmt.Fprintf(os.Stderr, "assertion 4 failed: expected KEY=value, got %v\n", env4)
		os.Exit(1)
	}

	// 5. gotenv.StrictParse returns error for syntax error input
	input5 := "INVALID LINE WITHOUT EQUALS\n"
	_, err = gotenv.StrictParse(strings.NewReader(input5))
	if err == nil {
		fmt.Fprintf(os.Stderr, "assertion 5 failed: expected error for invalid line, got nil\n")
		os.Exit(1)
	}

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