golang.org/x/tools v0.31.0: format Go source and fix imports using golang.org/x/tools/imports

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: format Go source and fix imports using golang.org/x/tools/imports
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/tools@v0.31.0
Demonstrate these symbols/APIs:
  - imports.Options
  - imports.Process
  - imports.VendorlessPath

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:sha256:210e9013737e0b6002b1e78f5b20f98ad0d1b33dd06fd65d2bd4922376523c55","contract":["imports.Process formats Go source code and automatically adds missing standard imports","imports.Process automatically removes unused imports from Go source code","imports.Process with Options.FormatOnly formats Go source code without modifying imports","imports.VendorlessPath strips vendor prefix from vendored package paths"],"goal":"format Go source and fix imports using golang.org/x/tools/imports","kind":"HOW","packages":["pkg:golang/golang.org/x/tools@v0.31.0"],"schemaVersion":1,"symbols":["imports.Options","imports.Process","imports.VendorlessPath"]},"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/tools@v0.31.0"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/tools@v0.31.0","symbols":["imports.Options","imports.Process","imports.VendorlessPath"],"verifierAdapter":"golang@1"}

module sample-golang-tools-imports

go 1.23.0

require golang.org/x/tools v0.31.0

require (
	golang.org/x/mod v0.24.0 // indirect
	golang.org/x/sync v0.12.0 // indirect
)

github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
golang.org/x/mod v0.24.0 h1:ZfthKaKaT4NrhGVZHO1/WDTwGES4De8KtWO0SIbNJMU=
golang.org/x/mod v0.24.0/go.mod h1:IXM97Txy2VM4PJ3gI61r1YEk/gAj6zAHN3AdZt6S9Ww=
golang.org/x/sync v0.12.0 h1:MHc5BpPuC30uJk597Ri8TV3CNZcTLu6B6z4lJy+g6Jw=
golang.org/x/sync v0.12.0/go.mod h1:1dzgHSNfp02xaA81J2MS99Qcpr2w7fw1gpm99rleRqA=
golang.org/x/tools v0.31.0 h1:0EedkvKDbh+qistFTd0Bcwe/YLh4vHwWEkiI0toFIBU=
golang.org/x/tools v0.31.0/go.mod h1:naFTU+Cev749tSJRXJlna0T3WxKvb1kWEx15xA4SdmQ=

package main

import (
	"fmt"

	"golang.org/x/tools/imports"
)

func main() {
	// 1. Process Go source code to automatically format and resolve imports
	unformatted := []byte("package main\n\nfunc main() {\nfmt.Println(\"Hello, World!\")\n}\n")
	opt := &imports.Options{
		TabWidth:  8,
		TabIndent: true,
		Comments:  true,
	}

	processed, err := imports.Process("main.go", unformatted, opt)
	if err != nil {
		fmt.Printf("Error processing source: %v\n", err)
		return
	}
	fmt.Printf("Formatted source:\n%s\n", string(processed))

	// 2. Resolve vendorless import path
	vendorPath := "example.com/project/vendor/golang.org/x/tools/imports"
	cleanPath := imports.VendorlessPath(vendorPath)
	fmt.Printf("Vendorless path: %s -> %s\n", vendorPath, cleanPath)
}

{
  "schemaVersion": 1,
  "goal": "format Go source and fix imports using golang.org/x/tools/imports",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/tools@v0.31.0"
  ],
  "symbols": [
    "imports.Options",
    "imports.Process",
    "imports.VendorlessPath"
  ]
}

package main

import (
	"fmt"
	"os"
	"strings"

	"golang.org/x/tools/imports"
)

func main() {
	// Assertion 1: imports.Process formats Go source code and automatically adds missing standard imports
	{
		src := []byte("package main\n\nfunc main() {\nfmt.Println(\"testing imports.Process\")\n}\n")
		res, err := imports.Process("main.go", src, nil)
		if err != nil {
			fmt.Fprintf(os.Stderr, "FAIL: imports.Process failed: %v\n", err)
			os.Exit(1)
		}
		expectedImport := "import \"fmt\""
		if !strings.Contains(string(res), expectedImport) {
			fmt.Fprintf(os.Stderr, "FAIL: imports.Process did not add missing fmt import:\n%s\n", string(res))
			os.Exit(1)
		}
	}

	// Assertion 2: imports.Process automatically removes unused imports from Go source code
	{
		src := []byte("package main\n\nimport (\n\t\"fmt\"\n\t\"os\"\n)\n\nfunc main() {\n\tfmt.Println(\"hello\")\n}\n")
		res, err := imports.Process("main.go", src, nil)
		if err != nil {
			fmt.Fprintf(os.Stderr, "FAIL: imports.Process failed: %v\n", err)
			os.Exit(1)
		}
		if strings.Contains(string(res), "\"os\"") {
			fmt.Fprintf(os.Stderr, "FAIL: imports.Process did not remove unused os import:\n%s\n", string(res))
			os.Exit(1)
		}
	}

	// Assertion 3: imports.Process with Options.FormatOnly formats Go source code without modifying imports
	{
		src := []byte("package main\n\nfunc main() {\nfmt.Println(\"no imports\")\n}\n")
		opt := &imports.Options{
			FormatOnly: true,
			TabWidth:   8,
			TabIndent:  true,
			Comments:   true,
		}
		res, err := imports.Process("main.go", src, opt)
		if err != nil {
			fmt.Fprintf(os.Stderr, "FAIL: imports.Process with FormatOnly failed: %v\n", err)
			os.Exit(1)
		}
		if strings.Contains(string(res), "import \"fmt\"") {
			fmt.Fprintf(os.Stderr, "FAIL: imports.Process with FormatOnly should not add imports:\n%s\n", string(res))
			os.Exit(1)
		}
	}

	// Assertion 4: imports.VendorlessPath strips vendor prefix from vendored package paths
	{
		testCases := []struct {
			input    string
			expected string
		}{
			{"github.com/example/repo/vendor/golang.org/x/tools/imports", "golang.org/x/tools/imports"},
			{"vendor/golang.org/x/tools/imports", "golang.org/x/tools/imports"},
			{"golang.org/x/tools/imports", "golang.org/x/tools/imports"},
			{"net/http", "net/http"},
		}
		for _, tc := range testCases {
			got := imports.VendorlessPath(tc.input)
			if got != tc.expected {
				fmt.Fprintf(os.Stderr, "FAIL: imports.VendorlessPath(%q) = %q, expected %q\n", tc.input, got, tc.expected)
				os.Exit(1)
			}
		}
	}

	fmt.Println("PASS: golang.org/x/tools/imports contract passed")
}