github.com/Masterminds/goutils v1.1.1: DefaultIfBlank

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/Masterminds/goutils.DefaultIfBlank in pkg:golang/github.com/Masterminds/goutils@v1.1.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/Masterminds/goutils@v1.1.1
Demonstrate these symbols/APIs:
  - github.com/Masterminds/goutils.DefaultIfBlank

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:sha256:5a6aab9499704d3a49789b3f713ffd28fd6635ff016ce7100bc4209f49a15efb","contract":["goutils.DefaultIfBlank returns the default string when input is empty","goutils.DefaultIfBlank returns the default string when input contains only whitespace","goutils.DefaultIfBlank returns the original string when input is non-blank","goutils.DefaultIfBlank preserves whitespace around non-blank string"],"goal":"verify github.com/Masterminds/goutils.DefaultIfBlank in pkg:golang/github.com/Masterminds/goutils@v1.1.1","kind":"HOW","packages":["pkg:golang/github.com/Masterminds/goutils@v1.1.1"],"schemaVersion":1,"symbols":["github.com/Masterminds/goutils.DefaultIfBlank"]},"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/Masterminds/goutils@v1.1.1"],"schemaVersion":1,"subject":"pkg:golang/github.com/Masterminds/goutils@v1.1.1","symbols":["github.com/Masterminds/goutils.DefaultIfBlank"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.26.6

require github.com/Masterminds/goutils v1.1.1

github.com/Masterminds/goutils v1.1.1 h1:5nUrii3FMTL5diU80unEVvNevw1nH4+ZV4DSLVJLSYI=
github.com/Masterminds/goutils v1.1.1/go.mod h1:8cTjp+g8YejhMuvIA5y2vz3BpJxksy863GQaJW2MFNU=

package main

import (
	"fmt"

	"github.com/Masterminds/goutils"
)

func main() {
	emptyResult := goutils.DefaultIfBlank("", "fallback")
	whitespaceResult := goutils.DefaultIfBlank("   ", "fallback")
	valueResult := goutils.DefaultIfBlank("hello", "fallback")

	fmt.Printf("empty result: %s\n", emptyResult)
	fmt.Printf("whitespace result: %s\n", whitespaceResult)
	fmt.Printf("value result: %s\n", valueResult)
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/Masterminds/goutils.DefaultIfBlank in pkg:golang/github.com/Masterminds/goutils@v1.1.1",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/Masterminds/goutils@v1.1.1"
  ],
  "symbols": [
    "github.com/Masterminds/goutils.DefaultIfBlank"
  ]
}

package main

import (
	"fmt"
	"os"

	"github.com/Masterminds/goutils"
)

func main() {
	// Assertion 1: Returns default when input is empty string
	if got := goutils.DefaultIfBlank("", "default_value"); got != "default_value" {
		fmt.Fprintf(os.Stderr, "DefaultIfBlank(\"\", \"default_value\") failed: got %q, want %q\n", got, "default_value")
		os.Exit(1)
	}

	// Assertion 2: Returns default when input is whitespace
	if got := goutils.DefaultIfBlank("   \t\n", "default_value"); got != "default_value" {
		fmt.Fprintf(os.Stderr, "DefaultIfBlank(\"   \\t\\n\", \"default_value\") failed: got %q, want %q\n", got, "default_value")
		os.Exit(1)
	}

	// Assertion 3: Returns original string when input is non-blank
	if got := goutils.DefaultIfBlank("hello", "default_value"); got != "hello" {
		fmt.Fprintf(os.Stderr, "DefaultIfBlank(\"hello\", \"default_value\") failed: got %q, want %q\n", got, "hello")
		os.Exit(1)
	}

	// Assertion 4: Returns original string preserving surrounding whitespace when input is non-blank
	if got := goutils.DefaultIfBlank("  hello  ", "default_value"); got != "  hello  " {
		fmt.Fprintf(os.Stderr, "DefaultIfBlank(\"  hello  \", \"default_value\") failed: got %q, want %q\n", got, "  hello  ")
		os.Exit(1)
	}

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