github.com/stretchr/testify v1.5.1: assert.False

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.False in pkg:golang/github.com/stretchr/testify@v1.5.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/stretchr/testify@v1.5.1
Demonstrate these symbols/APIs:
  - github.com/stretchr/testify/assert.False

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:bc30662063a0ae5bdff21d8943a0967f58f9a3f04361e7c22b650a6688ed3bc3","contract":["assert.False returns true and records no error when boolean expression is false","assert.False returns false and reports error when boolean expression is true","assert.False formats failure message using provided msgAndArgs","assert.False records error through TestingT Errorf interface without panicking"],"goal":"verify github.com/stretchr/testify/assert.False in pkg:golang/github.com/stretchr/testify@v1.5.1","kind":"HOW","packages":["pkg:golang/github.com/stretchr/testify@v1.5.1"],"schemaVersion":1,"symbols":["github.com/stretchr/testify/assert.False"]},"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@v1.5.1"],"schemaVersion":1,"subject":"pkg:golang/github.com/stretchr/testify@v1.5.1","symbols":["github.com/stretchr/testify/assert.False"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require github.com/stretchr/testify v1.5.1

require (
	github.com/davecgh/go-spew v1.1.0 // indirect
	github.com/pmezard/go-difflib v1.0.0 // indirect
	gopkg.in/yaml.v2 v2.2.2 // indirect
)

github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
github.com/davecgh/go-spew v1.1.0/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/testify v1.5.1 h1:nOGnQDM7FYENwehXlg/kFVnos3rEvtKTjRvOWSzb6H4=
github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
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.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

package main

import (
	"fmt"

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

// Reporter implements assert.TestingT to record assertion results.
type Reporter struct {
	Errors []string
	Passed int
	Failed int
}

func (r *Reporter) Errorf(format string, args ...interface{}) {
	r.Errors = append(r.Errors, fmt.Sprintf(format, args...))
	r.Failed++
}

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

	// Verify false literal passes
	if assert.False(reporter, false, "expected false to pass") {
		reporter.Passed++
	}

	// Verify boolean expression evaluating to false
	isActive := false
	if assert.False(reporter, isActive, "expected isActive to be false") {
		reporter.Passed++
	}

	// Verify true value fails assertion and records an error
	if !assert.False(reporter, true, "expected true value to fail False assertion") {
		// Failure is expected and recorded on reporter
	}

	fmt.Printf("Evaluation complete: %d passed, %d failed as expected\n", reporter.Passed, reporter.Failed)
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/stretchr/testify/assert.False in pkg:golang/github.com/stretchr/testify@v1.5.1",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/stretchr/testify@v1.5.1"
  ],
  "symbols": [
    "github.com/stretchr/testify/assert.False"
  ]
}

package main

import (
	"fmt"
	"os"
	"strings"

	"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...))
}

func main() {
	// Assertion 1: assert.False returns true and records no error when boolean expression is false
	{
		t := &contractTestingT{}
		res := assert.False(t, false)
		if !res || t.failed || len(t.errors) != 0 {
			fmt.Fprintf(os.Stderr, "assertion 1 failed: assert.False should return true with no error on literal false\n")
			os.Exit(1)
		}

		resExpr := assert.False(t, 10 > 20)
		if !resExpr || t.failed || len(t.errors) != 0 {
			fmt.Fprintf(os.Stderr, "assertion 1 failed: assert.False should return true with no error on false condition\n")
			os.Exit(1)
		}
	}

	// Assertion 2: assert.False returns false and reports error when boolean expression is true
	{
		t := &contractTestingT{}
		res := assert.False(t, true)
		if res || !t.failed || len(t.errors) == 0 {
			fmt.Fprintf(os.Stderr, "assertion 2 failed: assert.False should return false and report error on true\n")
			os.Exit(1)
		}

		resExpr := assert.False(t, 20 > 10)
		if resExpr || !t.failed || len(t.errors) == 0 {
			fmt.Fprintf(os.Stderr, "assertion 2 failed: assert.False should return false and report error on true condition\n")
			os.Exit(1)
		}
	}

	// Assertion 3: assert.False formats failure message using provided msgAndArgs
	{
		t := &contractTestingT{}
		customMsg := "custom verification message: flag was true"
		assert.False(t, true, "%s", customMsg)
		if !t.failed || len(t.errors) == 0 || !strings.Contains(t.errors[0], customMsg) {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: assert.False should include formatted custom message in error output\n")
			os.Exit(1)
		}
	}

	// Assertion 4: assert.False records error through TestingT Errorf interface without panicking
	{
		t := &contractTestingT{}
		didPanic := false
		func() {
			defer func() {
				if r := recover(); r != nil {
					didPanic = true
				}
			}()
			assert.False(t, true, "panic check")
		}()

		if didPanic || !t.failed || len(t.errors) == 0 {
			fmt.Fprintf(os.Stderr, "assertion 4 failed: assert.False should record failure via Errorf without panicking\n")
			os.Exit(1)
		}
	}

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