golang.org/x/tools v0.1.12: packages.Load

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 golang.org/x/tools/go/packages.Load in pkg:golang/golang.org/x/tools@v0.1.12
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/tools@v0.1.12
Demonstrate these symbols/APIs:
  - golang.org/x/tools/go/packages.Load

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:sha256:7538cbe2f9c7d66d315925358d12140f6769d9a91ad9778628fcf4084be5534b","contract":["packages.Load loads package metadata with packages.NeedName","packages.Load returns non-empty slice of packages for valid patterns","packages.Load populates PkgPath and ID on loaded packages","packages.Config allows specifying custom Dir and LoadMode","sample.LoadPackageNames returns expected package path for current module"],"goal":"verify golang.org/x/tools/go/packages.Load in pkg:golang/golang.org/x/tools@v0.1.12","kind":"HOW","packages":["pkg:golang/golang.org/x/tools@v0.1.12"],"schemaVersion":1,"symbols":["golang.org/x/tools/go/packages.Load"]},"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@v0.1.12"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/tools@v0.1.12","symbols":["golang.org/x/tools/go/packages.Load"],"verifierAdapter":"golang@1"}

module sample

go 1.22

require golang.org/x/tools v0.1.12

require (
	golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4 // indirect
	golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f // indirect
)

golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4 h1:6zppjxzCulZykYSLyVDYbneBfbaBIQPYMevg0bEwv2s=
golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f h1:v4INt8xihDGvnrfjMDVXGxw9wrfxYyCjk0KbXjhR55s=
golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/tools v0.1.12 h1:VveCTK38A2rkS8ZqFY25HIDFscX5X9OoEhJd3quQmXU=
golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=

package sample

import (
	"fmt"

	"golang.org/x/tools/go/packages"
)

// LoadPackages loads packages matching given patterns with specified mode.
func LoadPackages(dir string, mode packages.LoadMode, patterns ...string) ([]*packages.Package, error) {
	cfg := &packages.Config{
		Mode: mode,
		Dir:  dir,
	}
	pkgs, err := packages.Load(cfg, patterns...)
	if err != nil {
		return nil, fmt.Errorf("packages.Load failed: %w", err)
	}
	return pkgs, nil
}

// LoadPackageNames loads packages and returns their PkgPath list.
func LoadPackageNames(dir string, patterns ...string) ([]string, error) {
	pkgs, err := LoadPackages(dir, packages.NeedName, patterns...)
	if err != nil {
		return nil, err
	}
	names := make([]string, 0, len(pkgs))
	for _, pkg := range pkgs {
		names = append(names, pkg.PkgPath)
	}
	return names, nil
}

{
  "schemaVersion": 1,
  "goal": "verify golang.org/x/tools/go/packages.Load in pkg:golang/golang.org/x/tools@v0.1.12",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/tools@v0.1.12"
  ],
  "symbols": [
    "golang.org/x/tools/go/packages.Load"
  ]
}

package main

import (
	"fmt"
	"os"

	"golang.org/x/tools/go/packages"
	"sample"
)

func main() {
	// Assertion 1: packages.Load can load package metadata with packages.NeedName
	cfg := &packages.Config{
		Mode: packages.NeedName,
		Dir:  ".",
	}
	pkgs, err := packages.Load(cfg, ".")
	if err != nil {
		fmt.Fprintf(os.Stderr, "packages.Load failed: %v\n", err)
		os.Exit(1)
	}

	// Assertion 2: packages.Load returns non-empty slice of packages for valid package patterns
	if len(pkgs) == 0 {
		fmt.Fprintf(os.Stderr, "expected at least 1 package, got 0\n")
		os.Exit(1)
	}

	// Assertion 3: packages.Load populates PkgPath and ID on loaded packages
	pkg := pkgs[0]
	if pkg.PkgPath != "sample" {
		fmt.Fprintf(os.Stderr, "expected PkgPath 'sample', got %q\n", pkg.PkgPath)
		os.Exit(1)
	}
	if pkg.ID != "sample" {
		fmt.Fprintf(os.Stderr, "expected ID 'sample', got %q\n", pkg.ID)
		os.Exit(1)
	}

	// Assertion 4: packages.Config allows specifying custom Dir and LoadMode
	modeCfg := &packages.Config{
		Mode: packages.NeedName | packages.NeedFiles,
		Dir:  ".",
	}
	modePkgs, err := packages.Load(modeCfg, ".")
	if err != nil || len(modePkgs) == 0 {
		fmt.Fprintf(os.Stderr, "packages.Load with NeedFiles failed: %v\n", err)
		os.Exit(1)
	}
	if len(modePkgs[0].GoFiles) == 0 {
		fmt.Fprintf(os.Stderr, "expected GoFiles to be populated with NeedFiles mode\n")
		os.Exit(1)
	}

	// Assertion 5: sample.LoadPackageNames returns expected package path for current module
	names, err := sample.LoadPackageNames(".", ".")
	if err != nil {
		fmt.Fprintf(os.Stderr, "LoadPackageNames failed: %v\n", err)
		os.Exit(1)
	}
	if len(names) != 1 || names[0] != "sample" {
		fmt.Fprintf(os.Stderr, "expected ['sample'], got %v\n", names)
		os.Exit(1)
	}

	fmt.Println("All golang.org/x/tools/go/packages.Load contract assertions passed.")
}