golang.org/x/lint v0.0.0-20210508222113-6edffad5e616: Problem

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 lint.Problem in pkg:golang/golang.org/x/lint@v0.0.0-20210508222113-6edffad5e616
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/lint@v0.0.0-20210508222113-6edffad5e616
Demonstrate these symbols/APIs:
  - lint.Problem

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:b949127bf8a12b0419960a64fd1fbceac6bb64cc2a84b727b610ad93e61ab7aa","contract":["lint.Linter.Lint returns a slice of lint.Problem values populated with Position, Text, Link, Confidence, LineText, Category, and ReplacementLine","(*lint.Problem).String returns Text followed by two newlines and Link when Link is non-empty","(*lint.Problem).String returns only Text when Link is empty"],"goal":"verify lint.Problem in pkg:golang/golang.org/x/lint@v0.0.0-20210508222113-6edffad5e616","kind":"HOW","packages":["pkg:golang/golang.org/x/lint@v0.0.0-20210508222113-6edffad5e616"],"schemaVersion":1,"symbols":["lint.Problem"]},"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/golang.org/x/lint@v0.0.0-20210508222113-6edffad5e616"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/lint@v0.0.0-20210508222113-6edffad5e616","symbols":["lint.Problem"],"verifierAdapter":"golang@1"}

module example.com/sample

go 1.22

require golang.org/x/lint v0.0.0-20210508222113-6edffad5e616

require golang.org/x/tools v0.0.0-20200130002326-2f3ba24bd6e7 // indirect

golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
golang.org/x/lint v0.0.0-20210508222113-6edffad5e616 h1:VLliZ0d+/avPrXXH+OakdXhpJuEoBZuwh1m2j7U6Iug=
golang.org/x/lint v0.0.0-20210508222113-6edffad5e616/go.mod h1:3xt1FjdF8hUf6vQPIChWIBhFzV8gjjsPE/fR3IyQdNY=
golang.org/x/mod v0.1.1-0.20191105210325-c90efee705ee/go.mod h1:QqPTAvyqsEbceGzBzNggFXnrqF1CaUcvgkdR5Ot7KZg=
golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
golang.org/x/tools v0.0.0-20200130002326-2f3ba24bd6e7 h1:EBZoQjiKKPaLbPrbpssUfuHtwM6KV/vb4U85g/cigFY=
golang.org/x/tools v0.0.0-20200130002326-2f3ba24bd6e7/go.mod h1:TB2adYChydJhpapKDTa4BR/hXlZSLoq2Wpct/0txZ28=
golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

{
  "schemaVersion": 1,
  "goal": "verify lint.Problem in pkg:golang/golang.org/x/lint@v0.0.0-20210508222113-6edffad5e616",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/lint@v0.0.0-20210508222113-6edffad5e616"
  ],
  "symbols": [
    "lint.Problem"
  ]
}

package main

import (
	"fmt"
	"go/token"
	"os"

	"golang.org/x/lint"
)

func fail(msg string, args ...any) {
	fmt.Fprintf(os.Stderr, msg+"\n", args...)
	os.Exit(1)
}

func main() {
	src := []byte("package demo\n\nfunc run(xs []int) {\n\tfor _, _ = range xs {\n\t}\n}\n")
	var linter lint.Linter
	problems, err := linter.Lint("sample.go", src)
	if err != nil {
		fail("unexpected Lint error: %v", err)
	}
	if len(problems) != 2 {
		fail("expected 2 lint.Problem items, got %d", len(problems))
	}

	var p0 lint.Problem = problems[0]
	if p0.Position.Filename != "sample.go" || p0.Position.Line != 1 || p0.Position.Column != 1 {
		fail("unexpected p0.Position: %+v", p0.Position)
	}
	if p0.Category != "comments" {
		fail("expected p0.Category 'comments', got %q", p0.Category)
	}
	if p0.Confidence != 0.2 {
		fail("expected p0.Confidence 0.2, got %v", p0.Confidence)
	}
	if p0.Link == "" {
		fail("expected non-empty p0.Link")
	}
	if p0.ReplacementLine != "" {
		fail("expected empty p0.ReplacementLine, got %q", p0.ReplacementLine)
	}
	if p0.String() != p0.Text+"\n\n"+p0.Link {
		fail("expected p0.String() to include Text and Link, got %q", p0.String())
	}

	var p1 lint.Problem = problems[1]
	if p1.Position.Filename != "sample.go" || p1.Position.Line != 4 || p1.Position.Column != 6 {
		fail("unexpected p1.Position: %+v", p1.Position)
	}
	if p1.Category != "range-loop" {
		fail("expected p1.Category 'range-loop', got %q", p1.Category)
	}
	if p1.Confidence != 1.0 {
		fail("expected p1.Confidence 1.0, got %v", p1.Confidence)
	}
	expectedText := "should omit values from range; this loop is equivalent to `for range ...`"
	if p1.Text != expectedText {
		fail("expected p1.Text %q, got %q", expectedText, p1.Text)
	}
	if p1.LineText != "\tfor _, _ = range xs {\n" {
		fail("unexpected p1.LineText: %q", p1.LineText)
	}
	if p1.ReplacementLine != "\tfor range xs {" {
		fail("unexpected p1.ReplacementLine: %q", p1.ReplacementLine)
	}
	if p1.Link != "" {
		fail("expected empty p1.Link, got %q", p1.Link)
	}
	if p1.String() != expectedText {
		fail("expected p1.String() without Link to return %q, got %q", expectedText, p1.String())
	}

	custom := lint.Problem{
		Position: token.Position{
			Filename: "sample.go",
			Line:     10,
			Column:   2,
		},
		Text:       "exported function should have comment",
		Link:       "https://example.com/style-guide",
		Confidence: 0.8,
		LineText:   "func Exported() {}",
		Category:   "comments",
	}
	expectedCustomString := "exported function should have comment\n\nhttps://example.com/style-guide"
	if custom.String() != expectedCustomString {
		fail("expected custom.String() to return %q, got %q", expectedCustomString, custom.String())
	}
}