github.com/russross/blackfriday/v2 v2.1.0: WithNoExtensions

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/russross/blackfriday/v2.WithNoExtensions in pkg:golang/github.com/russross/blackfriday/v2@v2.1.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/russross/blackfriday/v2@v2.1.0
Demonstrate these symbols/APIs:
  - github.com/russross/blackfriday/v2.WithNoExtensions

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:sha256:7db211861c361493afbaa819bbcd751720e17350f460130b9385e68f4cfed1d7","contract":["blackfriday.WithNoExtensions disables default extensions including autolink generation","blackfriday.WithNoExtensions disables strikethrough del tags and preserves raw tildes","blackfriday.WithNoExtensions disables fenced code block parsing","blackfriday.New with WithNoExtensions configures AST parser with no Del extension nodes"],"goal":"verify github.com/russross/blackfriday/v2.WithNoExtensions in pkg:golang/github.com/russross/blackfriday/v2@v2.1.0","kind":"HOW","packages":["pkg:golang/github.com/russross/blackfriday/v2@v2.1.0"],"schemaVersion":1,"symbols":["github.com/russross/blackfriday/v2.WithNoExtensions"]},"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/russross/blackfriday/v2@v2.1.0"],"schemaVersion":1,"subject":"pkg:golang/github.com/russross/blackfriday/v2@v2.1.0","symbols":["github.com/russross/blackfriday/v2.WithNoExtensions"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require github.com/russross/blackfriday/v2 v2.1.0

github.com/russross/blackfriday/v2 v2.1.0 h1:JIOH55/0cWyOuilr9/qlrm0BSXldqnqwMsf35Ld67mk=
github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=

package main

import (
	"fmt"

	"github.com/russross/blackfriday/v2"
)

func main() {
	markdown := []byte("Standard Markdown without extensions: ~~strikethrough~~ and http://example.com")
	html := blackfriday.Run(markdown, blackfriday.WithNoExtensions())
	fmt.Printf("Rendered HTML:\n%s\n", string(html))
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/russross/blackfriday/v2.WithNoExtensions in pkg:golang/github.com/russross/blackfriday/v2@v2.1.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/russross/blackfriday/v2@v2.1.0"
  ],
  "symbols": [
    "github.com/russross/blackfriday/v2.WithNoExtensions"
  ]
}

package main

import (
	"fmt"
	"os"
	"strings"

	"github.com/russross/blackfriday/v2"
)

func main() {
	if err := runContract(); err != nil {
		fmt.Fprintf(os.Stderr, "Contract verification failed: %v\n", err)
		os.Exit(1)
	}
	fmt.Println("All WithNoExtensions contract assertions passed successfully.")
}

func runContract() error {
	// Assertion 1: blackfriday.WithNoExtensions disables default extensions such as autolink
	inputAutolink := []byte("Visit http://example.com directly.")
	outputDefault := blackfriday.Run(inputAutolink)
	if !strings.Contains(string(outputDefault), `<a href="http://example.com">http://example.com</a>`) {
		return fmt.Errorf("expected default run to include autolink anchor, got: %s", string(outputDefault))
	}
	outputNoExt := blackfriday.Run(inputAutolink, blackfriday.WithNoExtensions())
	if strings.Contains(string(outputNoExt), `<a href=`) {
		return fmt.Errorf("expected WithNoExtensions to disable autolinks, got: %s", string(outputNoExt))
	}
	if !strings.Contains(string(outputNoExt), "<p>Visit http://example.com directly.</p>") {
		return fmt.Errorf("expected plain paragraph text with raw URL, got: %s", string(outputNoExt))
	}

	// Assertion 2: blackfriday.WithNoExtensions disables strikethrough syntax
	inputStrikethrough := []byte("This is ~~obsolete~~ text.")
	outputStrike := blackfriday.Run(inputStrikethrough, blackfriday.WithNoExtensions())
	if strings.Contains(string(outputStrike), "<del>") {
		return fmt.Errorf("expected WithNoExtensions to disable strikethrough del tags, got: %s", string(outputStrike))
	}
	if !strings.Contains(string(outputStrike), "<p>This is ~~obsolete~~ text.</p>") {
		return fmt.Errorf("expected raw tildes preserved in paragraph, got: %s", string(outputStrike))
	}

	// Assertion 3: blackfriday.WithNoExtensions disables fenced code blocks
	inputFenced := []byte("```go\nfmt.Println(\"hello\")\n```")
	outputFenced := blackfriday.Run(inputFenced, blackfriday.WithNoExtensions())
	if strings.Contains(string(outputFenced), "<pre><code") {
		return fmt.Errorf("expected WithNoExtensions to disable fenced code parsing, got: %s", string(outputFenced))
	}

	// Assertion 4: blackfriday.New with WithNoExtensions configures parser with zero extension flags
	parser := blackfriday.New(blackfriday.WithNoExtensions())
	ast := parser.Parse([]byte("~~not deleted~~"))
	if ast == nil || ast.Type != blackfriday.Document {
		return fmt.Errorf("expected Document root AST node, got: %v", ast)
	}
	// Walk AST to verify no Del (strikethrough) node is produced
	hasDelNode := false
	ast.Walk(func(node *blackfriday.Node, entering bool) blackfriday.WalkStatus {
		if node.Type == blackfriday.Del {
			hasDelNode = true
			return blackfriday.Terminate
		}
		return blackfriday.GoToNext
	})
	if hasDelNode {
		return fmt.Errorf("expected AST to contain no Del nodes when WithNoExtensions is used")
	}

	return nil
}