github.com/stretchr/testify v1.8.1: assert.ElementsMatch

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/stretchr/testify/assert.ElementsMatch in pkg:golang/github.com/stretchr/testify@v1.8.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/stretchr/testify@v1.8.1
Demonstrate these symbols/APIs:
  - github.com/stretchr/testify/assert.ElementsMatch

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:sha256:0f26f1ae85b3f19b75d213bcb3edda32ae04cc96b790addaba5e3c1f820a42ca","contract":["assert.ElementsMatch returns true and does not record an error when two slices contain identical elements in different order","assert.ElementsMatch enforces element frequency and returns false with an error when duplicate counts differ","assert.ElementsMatch returns false and records an error when slices contain different elements or lengths","assert.ElementsMatch returns true for empty or nil slice comparisons of matching zero elements","assert.ElementsMatch returns true when comparing slices of struct values with matching fields in different order"],"goal":"verify github.com/stretchr/testify/assert.ElementsMatch in pkg:golang/github.com/stretchr/testify@v1.8.1","kind":"HOW","packages":["pkg:golang/github.com/stretchr/testify@v1.8.1"],"schemaVersion":1,"symbols":["github.com/stretchr/testify/assert.ElementsMatch"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","language":"go","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","packageManagerVersion":"1.26.6","runtime":"go","runtimeVersion":"1.26.6","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/github.com/stretchr/testify@v1.8.1"],"schemaVersion":1,"subject":"pkg:golang/github.com/stretchr/testify@v1.8.1","symbols":["github.com/stretchr/testify/assert.ElementsMatch"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require github.com/stretchr/testify v1.8.1

require (
	github.com/davecgh/go-spew v1.1.1 // indirect
	github.com/pmezard/go-difflib v1.0.0 // indirect
	gopkg.in/yaml.v3 v3.0.1 // 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/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 v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
github.com/stretchr/testify v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKsk=
github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
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 main

import (
	"fmt"

	"github.com/stretchr/testify/assert"
)

// Reporter implements assert.TestingT to collect assertion failures.
type Reporter struct {
	errors []string
	failed bool
}

func (r *Reporter) Errorf(format string, args ...interface{}) {
	r.failed = true
	r.errors = append(r.errors, fmt.Sprintf(format, args...))
}

// Item represents an entity with an identifier and name.
type Item struct {
	ID   int
	Name string
}

func main() {
	reporter := &Reporter{}

	// Example 1: Comparing string slices regardless of ordering
	expectedTags := []string{"backend", "golang", "database"}
	actualTags := []string{"database", "backend", "golang"}

	if assert.ElementsMatch(reporter, expectedTags, actualTags, "tags should match regardless of order") {
		fmt.Println("Tags matched successfully regardless of order.")
	}

	// Example 2: Comparing struct slices with identical elements in different order
	expectedItems := []Item{{ID: 1, Name: "alpha"}, {ID: 2, Name: "beta"}}
	actualItems := []Item{{ID: 2, Name: "beta"}, {ID: 1, Name: "alpha"}}

	if assert.ElementsMatch(reporter, expectedItems, actualItems, "items should match regardless of order") {
		fmt.Println("Items matched successfully regardless of order.")
	}

	if !reporter.failed {
		fmt.Println("All ElementsMatch demonstrations completed without errors.")
	}
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/stretchr/testify/assert.ElementsMatch in pkg:golang/github.com/stretchr/testify@v1.8.1",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/stretchr/testify@v1.8.1"
  ],
  "symbols": [
    "github.com/stretchr/testify/assert.ElementsMatch"
  ]
}

package main

import (
	"fmt"
	"os"

	"github.com/stretchr/testify/assert"
)

type contractTestingT struct {
	errors []string
	failed bool
}

func (t *contractTestingT) Errorf(format string, args ...interface{}) {
	t.failed = true
	t.errors = append(t.errors, fmt.Sprintf(format, args...))
}

type structItem struct {
	ID   int
	Name string
}

func main() {
	// Assertion 1: assert.ElementsMatch returns true and does not record an error when two slices contain identical elements in different order
	{
		t := &contractTestingT{}
		sliceA := []string{"apple", "banana", "cherry"}
		sliceB := []string{"cherry", "apple", "banana"}
		if !assert.ElementsMatch(t, sliceA, sliceB) || t.failed || len(t.errors) != 0 {
			fmt.Fprintf(os.Stderr, "assertion 1 failed: ElementsMatch should succeed on permutations\n")
			os.Exit(1)
		}
	}

	// Assertion 2: assert.ElementsMatch enforces element frequency and returns false with an error when duplicate counts differ
	{
		tSuccess := &contractTestingT{}
		listA := []int{1, 2, 2, 3}
		listB := []int{2, 3, 1, 2}
		if !assert.ElementsMatch(tSuccess, listA, listB) || tSuccess.failed || len(tSuccess.errors) != 0 {
			fmt.Fprintf(os.Stderr, "assertion 2 failed: ElementsMatch should succeed when duplicate counts match\n")
			os.Exit(1)
		}

		tFail := &contractTestingT{}
		listC := []int{1, 2, 3, 3}
		if assert.ElementsMatch(tFail, listA, listC) || !tFail.failed || len(tFail.errors) == 0 {
			fmt.Fprintf(os.Stderr, "assertion 2 failed: ElementsMatch should return false when duplicate frequencies differ\n")
			os.Exit(1)
		}
	}

	// Assertion 3: assert.ElementsMatch returns false and records an error when slices contain different elements or lengths
	{
		tDiffElem := &contractTestingT{}
		sliceA := []string{"apple", "banana"}
		sliceB := []string{"apple", "cherry"}
		if assert.ElementsMatch(tDiffElem, sliceA, sliceB) || !tDiffElem.failed || len(tDiffElem.errors) == 0 {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: ElementsMatch should fail on different elements\n")
			os.Exit(1)
		}

		tDiffLen := &contractTestingT{}
		sliceC := []string{"apple", "banana", "cherry"}
		if assert.ElementsMatch(tDiffLen, sliceA, sliceC) || !tDiffLen.failed || len(tDiffLen.errors) == 0 {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: ElementsMatch should fail on different lengths\n")
			os.Exit(1)
		}
	}

	// Assertion 4: assert.ElementsMatch returns true for empty or nil slice comparisons of matching zero elements
	{
		t := &contractTestingT{}
		var nilSlice []int
		emptySlice := []int{}
		if !assert.ElementsMatch(t, nilSlice, emptySlice) || t.failed || len(t.errors) != 0 {
			fmt.Fprintf(os.Stderr, "assertion 4 failed: ElementsMatch should succeed on nil vs empty slice\n")
			os.Exit(1)
		}

		tEmpty := &contractTestingT{}
		if !assert.ElementsMatch(tEmpty, []string{}, []string{}) || tEmpty.failed || len(tEmpty.errors) != 0 {
			fmt.Fprintf(os.Stderr, "assertion 4 failed: ElementsMatch should succeed on two empty slices\n")
			os.Exit(1)
		}
	}

	// Assertion 5: assert.ElementsMatch returns true when comparing slices of struct values with matching fields in different order
	{
		t := &contractTestingT{}
		itemsA := []structItem{{ID: 1, Name: "alpha"}, {ID: 2, Name: "beta"}}
		itemsB := []structItem{{ID: 2, Name: "beta"}, {ID: 1, Name: "alpha"}}
		if !assert.ElementsMatch(t, itemsA, itemsB) || t.failed || len(t.errors) != 0 {
			fmt.Fprintf(os.Stderr, "assertion 5 failed: ElementsMatch should succeed on struct slices with permuted elements\n")
			os.Exit(1)
		}

		tMismatch := &contractTestingT{}
		itemsC := []structItem{{ID: 1, Name: "alpha"}, {ID: 2, Name: "gamma"}}
		if assert.ElementsMatch(tMismatch, itemsA, itemsC) || !tMismatch.failed || len(tMismatch.errors) == 0 {
			fmt.Fprintf(os.Stderr, "assertion 5 failed: ElementsMatch should fail on struct slice mismatch\n")
			os.Exit(1)
		}
	}

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