github.com/spf13/cast v1.10.0: ToStringSlice

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/spf13/cast@v1.10.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/spf13/cast@v1.10.0
Demonstrate these symbols/APIs:
  - github.com/spf13/cast.ToStringSlice

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.

package sample

import (
	"github.com/spf13/cast"
)

// ToStringSlice converts an arbitrary value into a slice of strings using cast.ToStringSlice.
// It returns nil if conversion cannot be performed.
func ToStringSlice(v any) []string {
	return cast.ToStringSlice(v)
}

// ToStringSliceE converts an arbitrary value into a slice of strings using cast.ToStringSliceE,
// returning an error if conversion cannot be performed.
func ToStringSliceE(v any) ([]string, error) {
	return cast.ToStringSliceE(v)
}

package sample

import (
	"reflect"
	"testing"

	"github.com/spf13/cast"
)

func TestToStringSlice_StringSlice(t *testing.T) {
	orig := []string{"apple", "banana", "cherry"}
	got := cast.ToStringSlice(orig)
	if !reflect.DeepEqual(got, orig) {
		t.Fatalf("cast.ToStringSlice(%v) = %v; want %v", orig, got, orig)
	}

	gotE, err := cast.ToStringSliceE(orig)
	if err != nil {
		t.Fatalf("cast.ToStringSliceE(%v) unexpected error: %v", orig, err)
	}
	if !reflect.DeepEqual(gotE, orig) {
		t.Fatalf("cast.ToStringSliceE(%v) = %v; want %v", orig, gotE, orig)
	}
}

func TestToStringSlice_GenericAndTypedSlices(t *testing.T) {
	anySlice := []any{"hello", 42, true, 3.14}
	wantAny := []string{"hello", "42", "true", "3.14"}
	if got := cast.ToStringSlice(anySlice); !reflect.DeepEqual(got, wantAny) {
		t.Fatalf("cast.ToStringSlice(%v) = %v; want %v", anySlice, got, wantAny)
	}

	intSlice := []int{10, 20, -30}
	wantInt := []string{"10", "20", "-30"}
	if got := cast.ToStringSlice(intSlice); !reflect.DeepEqual(got, wantInt) {
		t.Fatalf("cast.ToStringSlice(%v) = %v; want %v", intSlice, got, wantInt)
	}

	boolSlice := []bool{true, false}
	wantBool := []string{"true", "false"}
	if got := cast.ToStringSlice(boolSlice); !reflect.DeepEqual(got, wantBool) {
		t.Fatalf("cast.ToStringSlice(%v) = %v; want %v", boolSlice, got, wantBool)
	}
}

func TestToStringSlice_Scalars(t *testing.T) {
	str := "standalone"
	if got := cast.ToStringSlice(str); !reflect.DeepEqual(got, []string{"standalone"}) {
		t.Fatalf("cast.ToStringSlice(%q) = %v; want [\"standalone\"]", str, got)
	}

	num := 999
	if got := cast.ToStringSlice(num); !reflect.DeepEqual(got, []string{"999"}) {
		t.Fatalf("cast.ToStringSlice(%d) = %v; want [\"999\"]", num, got)
	}

	b := true
	if got := cast.ToStringSlice(b); !reflect.DeepEqual(got, []string{"true"}) {
		t.Fatalf("cast.ToStringSlice(%v) = %v; want [\"true\"]", b, got)
	}
}

func TestToStringSlice_Pointers(t *testing.T) {
	sliceVal := []string{"foo", "bar"}
	if got := cast.ToStringSlice(&sliceVal); !reflect.DeepEqual(got, sliceVal) {
		t.Fatalf("cast.ToStringSlice(&%v) = %v; want %v", sliceVal, got, sliceVal)
	}

	scalarStr := "pointer_test"
	if got := cast.ToStringSlice(&scalarStr); !reflect.DeepEqual(got, []string{"pointer_test"}) {
		t.Fatalf("cast.ToStringSlice(&%q) = %v; want [\"pointer_test\"]", scalarStr, got)
	}

	scalarInt := 123
	if got := cast.ToStringSlice(&scalarInt); !reflect.DeepEqual(got, []string{"123"}) {
		t.Fatalf("cast.ToStringSlice(&%d) = %v; want [\"123\"]", scalarInt, got)
	}
}

func TestToStringSlice_Nil(t *testing.T) {
	if got := cast.ToStringSlice(nil); got != nil {
		t.Fatalf("cast.ToStringSlice(nil) = %v; want nil", got)
	}
	val, err := cast.ToStringSliceE(nil)
	if err == nil {
		t.Fatalf("cast.ToStringSliceE(nil) expected error, got nil error with val %v", val)
	}
	if val != nil {
		t.Fatalf("cast.ToStringSliceE(nil) = %v; want nil", val)
	}
}

func TestToStringSlice_UnsupportedTypes(t *testing.T) {
	unsupported := []any{
		map[string]int{"a": 1},
		struct{ Name string }{Name: "example"},
		func() {},
	}
	for _, val := range unsupported {
		if got := cast.ToStringSlice(val); got != nil {
			t.Fatalf("cast.ToStringSlice(%v) = %v; want nil", val, got)
		}
		if _, err := cast.ToStringSliceE(val); err == nil {
			t.Fatalf("cast.ToStringSliceE(%v) expected error, got nil", val)
		}
	}
}

func TestToStringSlice_Helper(t *testing.T) {
	cases := []any{
		[]string{"x", "y"},
		[]int{1, 2},
		"hello",
		123,
	}
	for _, c := range cases {
		expected := cast.ToStringSlice(c)
		if got := ToStringSlice(c); !reflect.DeepEqual(got, expected) {
			t.Fatalf("ToStringSlice(%v) = %v; want %v", c, got, expected)
		}
		gotE, err := ToStringSliceE(c)
		if err != nil {
			t.Fatalf("ToStringSliceE(%v) unexpected error: %v", c, err)
		}
		if !reflect.DeepEqual(gotE, expected) {
			t.Fatalf("ToStringSliceE(%v) = %v; want %v", c, gotE, expected)
		}
	}
}

{"case":{"caseId":"case:sha256:ea3fed646a65b910ad00164a84db6cd1f77bfbb5d8e50ec495f31f42553653bf","contract":["cast.ToStringSlice returns unchanged string slice when passed []string","cast.ToStringSlice converts elements of generic slices and typed slices to []string","cast.ToStringSlice converts single scalar values into single-element string slices","cast.ToStringSlice unwraps pointer values before converting their underlying values to []string","cast.ToStringSlice returns nil and cast.ToStringSliceE returns an error for nil values","cast.ToStringSlice returns nil and cast.ToStringSliceE returns an error for unsupported types","ToStringSlice converts the given value to a slice of strings using cast.ToStringSlice"],"goal":"verify pkg:golang/github.com/spf13/cast@v1.10.0","kind":"HOW","packages":["pkg:golang/github.com/spf13/cast@v1.10.0"],"schemaVersion":1,"symbols":["github.com/spf13/cast.ToStringSlice"]},"contractCommand":["go","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/spf13/cast@v1.10.0"],"schemaVersion":1,"subject":"pkg:golang/github.com/spf13/cast@v1.10.0","symbols":["github.com/spf13/cast.ToStringSlice"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.26.6

require github.com/spf13/cast v1.10.0

github.com/frankban/quicktest v1.14.6 h1:7Xjx+VpznH+oBnejlPUj8oUpdxnVs4f8XU8WnHkI4W8=
github.com/frankban/quicktest v1.14.6/go.mod h1:4ptaffx2x8+WTWXmUCuVU6aPUX1/Mz7zb5vbUoiM6w0=
github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8=
github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
github.com/spf13/cast v1.10.0 h1:h2x0u2shc1QuLHfxi+cTJvs30+ZAHOGRic8uyGTDWxY=
github.com/spf13/cast v1.10.0/go.mod h1:jNfB8QC9IA6ZuY2ZjDp0KtFO2LZZlg4S/7bzP6qqeHo=

{
  "schemaVersion": 1,
  "goal": "verify pkg:golang/github.com/spf13/cast@v1.10.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/spf13/cast@v1.10.0"
  ],
  "symbols": [
    "github.com/spf13/cast.ToStringSlice"
  ]
}