github.com/stretchr/objx v0.2.0

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 pkg:golang/github.com/stretchr/objx@v0.2.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/stretchr/objx@v0.2.0

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:sha256:851d7127bb7cf62931e4ea9a91df7385688bd6465d52ab65f017c7106a1010cf","contract":["objx.New wraps a map and accesses nested fields via Get and dot notation","objx.Map.Get supports array index notation and type conversion","objx.Map.Set updates nested values by selector","objx.Map.Has checks existence of top-level and nested keys"],"goal":"verify pkg:golang/github.com/stretchr/objx@v0.2.0","kind":"HOW","packages":["pkg:golang/github.com/stretchr/objx@v0.2.0"],"schemaVersion":1},"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/stretchr/objx@v0.2.0"],"schemaVersion":1,"subject":"pkg:golang/github.com/stretchr/objx@v0.2.0","verifierAdapter":"golang@1"}

module example.com/sample

go 1.26.6

require github.com/stretchr/objx v0.2.0

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/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/objx v0.2.0 h1:Hbg2NidpLE8veEBkEZTL3CvlkUIVzuU9jDplZO54c48=
github.com/stretchr/objx v0.2.0/go.mod h1:qt09Ya8vawLte6SNmTgCsAVtYtaKzEcn8ATUoHMkEqE=
github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=

package main

import (
	"fmt"

	"github.com/stretchr/objx"
)

func main() {
	m := objx.New(map[string]interface{}{
		"service": map[string]interface{}{
			"name": "auth",
			"port": 8080,
			"endpoints": []interface{}{
				"/login",
				"/logout",
			},
		},
	})

	name := m.Get("service.name").Str()
	port := m.Get("service.port").Int()
	endpoint := m.Get("service.endpoints[0]").Str()
	hasPort := m.Has("service.port")

	m.Set("service.name", "auth-v2")
	updatedName := m.Get("service.name").Str()

	fmt.Printf("service: %s, port: %d, endpoint: %s, hasPort: %t, updated: %s\n",
		name, port, endpoint, hasPort, updatedName)
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:golang/github.com/stretchr/objx@v0.2.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/stretchr/objx@v0.2.0"
  ]
}

package main

import (
	"fmt"
	"os"

	"github.com/stretchr/objx"
)

func main() {
	m := objx.New(map[string]interface{}{
		"service": map[string]interface{}{
			"name": "auth",
			"port": 8080,
			"endpoints": []interface{}{
				"/login",
				"/logout",
			},
		},
	})

	// Assertion 1: objx.New wraps a map and accesses nested fields via Get and dot notation
	if m.Get("service.name").Str() != "auth" {
		fmt.Fprintf(os.Stderr, "contract assertion 1 failed: expected nested name to be 'auth', got '%s'\n", m.Get("service.name").Str())
		os.Exit(1)
	}

	// Assertion 2: objx.Map.Get supports array index notation and type conversion
	if m.Get("service.endpoints[0]").Str() != "/login" || m.Get("service.port").Int() != 8080 {
		fmt.Fprintf(os.Stderr, "contract assertion 2 failed: expected array index and int conversion to succeed\n")
		os.Exit(1)
	}

	// Assertion 3: objx.Map.Set updates nested values by selector
	m.Set("service.name", "auth-v2")
	if m.Get("service.name").Str() != "auth-v2" {
		fmt.Fprintf(os.Stderr, "contract assertion 3 failed: expected updated name to be 'auth-v2'\n")
		os.Exit(1)
	}

	// Assertion 4: objx.Map.Has checks existence of top-level and nested keys
	if !m.Has("service.name") || !m.Has("service.endpoints[1]") || m.Has("service.missing") {
		fmt.Fprintf(os.Stderr, "contract assertion 4 failed: expected Has to return true for existing keys and false for missing keys\n")
		os.Exit(1)
	}

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