google.golang.org/api v0.273.1

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 pkg:golang/google.golang.org/api@v0.273.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/google.golang.org/api@v0.273.1

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:sha256:3c77a374c9f89e9c6808b4e4feabb7773b82c260c28b6162fea28bc8a4963ef2","contract":["transport/http.NewClient with option.WithEndpoint and option.WithoutAuthentication returns a configured *http.Client and the custom endpoint string","googleapi.Expand substitutes path template placeholders and googleapi.CombineFields serializes field selectors into a comma-separated string","googleapi.CheckResponse returns nil on HTTP 200 and parses HTTP 404 JSON error responses into *googleapi.Error with Code, Message, and Errors"],"goal":"verify pkg:golang/google.golang.org/api@v0.273.1","kind":"HOW","packages":["pkg:golang/google.golang.org/api@v0.273.1"],"schemaVersion":1},"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/google.golang.org/api@v0.273.1"],"schemaVersion":1,"subject":"pkg:golang/google.golang.org/api@v0.273.1","verifierAdapter":"golang@1"}

module sample

go 1.25.0

require google.golang.org/api v0.273.1

require (
	cloud.google.com/go/auth v0.18.2 // indirect
	cloud.google.com/go/auth/oauth2adapt v0.2.8 // indirect
	cloud.google.com/go/compute/metadata v0.9.0 // indirect
	github.com/cespare/xxhash/v2 v2.3.0 // indirect
	github.com/felixge/httpsnoop v1.0.4 // indirect
	github.com/go-logr/logr v1.4.3 // indirect
	github.com/go-logr/stdr v1.2.2 // indirect
	github.com/google/s2a-go v0.1.9 // indirect
	github.com/googleapis/enterprise-certificate-proxy v0.3.14 // indirect
	github.com/googleapis/gax-go/v2 v2.19.0 // indirect
	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.61.0 // indirect
	go.opentelemetry.io/otel v1.42.0 // indirect
	go.opentelemetry.io/otel/metric v1.42.0 // indirect
	go.opentelemetry.io/otel/trace v1.42.0 // indirect
	golang.org/x/crypto v0.49.0 // indirect
	golang.org/x/net v0.52.0 // indirect
	golang.org/x/oauth2 v0.36.0 // indirect
	golang.org/x/sys v0.42.0 // indirect
	golang.org/x/text v0.35.0 // indirect
	google.golang.org/genproto/googleapis/rpc v0.0.0-20260319201613-d00831a3d3e7 // indirect
	google.golang.org/grpc v1.79.3 // indirect
	google.golang.org/protobuf v1.36.11 // indirect
)

cloud.google.com/go/auth v0.18.2 h1:+Nbt5Ev0xEqxlNjd6c+yYUeosQ5TtEUaNcN/3FozlaM=
cloud.google.com/go/auth v0.18.2/go.mod h1:xD+oY7gcahcu7G2SG2DsBerfFxgPAJz17zz2joOFF3M=
cloud.google.com/go/auth/oauth2adapt v0.2.8 h1:keo8NaayQZ6wimpNSmW5OPc283g65QNIiLpZnkHRbnc=
cloud.google.com/go/auth/oauth2adapt v0.2.8/go.mod h1:XQ9y31RkqZCcwJWNSx2Xvric3RrU88hAYYbjDWYDL+c=
cloud.google.com/go/compute/metadata v0.9.0 h1:pDUj4QMoPejqq20dK0Pg2N4yG9zIkYGdBtwLoEkH9Zs=
cloud.google.com/go/compute/metadata v0.9.0/go.mod h1:E0bWwX5wTnLPedCKqk3pJmVgCBSM6qQI1yTBdEb3C10=
github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/felixge/httpsnoop v1.0.4 h1:NFTV2Zj1bL4mc9sqWACXbQFVBBg2W3GPvqp8/ESS2Wg=
github.com/felixge/httpsnoop v1.0.4/go.mod h1:m8KPJKqk1gH5J9DgRY2ASl2lWCfGKXixSwevea8zH2U=
github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
github.com/go-logr/logr v1.4.3 h1:CjnDlHq8ikf6E492q6eKboGOC0T8CDaOvkHCIg8idEI=
github.com/go-logr/logr v1.4.3/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
github.com/google/s2a-go v0.1.9 h1:LGD7gtMgezd8a/Xak7mEWL0PjoTQFvpRudN895yqKW0=
github.com/google/s2a-go v0.1.9/go.mod h1:YA0Ei2ZQL3acow2O62kdp9UlnvMmU7kA6Eutn0dXayM=
github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
github.com/googleapis/enterprise-certificate-proxy v0.3.14 h1:yh8ncqsbUY4shRD5dA6RlzjJaT4hi3kII+zYw8wmLb8=
github.com/googleapis/enterprise-certificate-proxy v0.3.14/go.mod h1:vqVt9yG9480NtzREnTlmGSBmFrA+bzb0yl0TxoBQXOg=
github.com/googleapis/gax-go/v2 v2.19.0 h1:fYQaUOiGwll0cGj7jmHT/0nPlcrZDFPrZRhTsoCr8hE=
github.com/googleapis/gax-go/v2 v2.19.0/go.mod h1:w2ROXVdfGEVFXzmlciUU4EdjHgWvB5h2n6x/8XSTTJA=
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/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
go.opentelemetry.io/auto/sdk v1.2.1 h1:jXsnJ4Lmnqd11kwkBV2LgLoFMZKizbCi5fNZ/ipaZ64=
go.opentelemetry.io/auto/sdk v1.2.1/go.mod h1:KRTj+aOaElaLi+wW1kO/DZRXwkF4C5xPbEe3ZiIhN7Y=
go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.61.0 h1:F7Jx+6hwnZ41NSFTO5q4LYDtJRXBf2PD0rNBkeB/lus=
go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.61.0/go.mod h1:UHB22Z8QsdRDrnAtX4PntOl36ajSxcdUMt1sF7Y6E7Q=
go.opentelemetry.io/otel v1.42.0 h1:lSQGzTgVR3+sgJDAU/7/ZMjN9Z+vUip7leaqBKy4sho=
go.opentelemetry.io/otel v1.42.0/go.mod h1:lJNsdRMxCUIWuMlVJWzecSMuNjE7dOYyWlqOXWkdqCc=
go.opentelemetry.io/otel/metric v1.42.0 h1:2jXG+3oZLNXEPfNmnpxKDeZsFI5o4J+nz6xUlaFdF/4=
go.opentelemetry.io/otel/metric v1.42.0/go.mod h1:RlUN/7vTU7Ao/diDkEpQpnz3/92J9ko05BIwxYa2SSI=
go.opentelemetry.io/otel/sdk v1.42.0 h1:LyC8+jqk6UJwdrI/8VydAq/hvkFKNHZVIWuslJXYsDo=
go.opentelemetry.io/otel/sdk v1.42.0/go.mod h1:rGHCAxd9DAph0joO4W6OPwxjNTYWghRWmkHuGbayMts=
go.opentelemetry.io/otel/sdk/metric v1.42.0 h1:D/1QR46Clz6ajyZ3G8SgNlTJKBdGp84q9RKCAZ3YGuA=
go.opentelemetry.io/otel/sdk/metric v1.42.0/go.mod h1:Ua6AAlDKdZ7tdvaQKfSmnFTdHx37+J4ba8MwVCYM5hc=
go.opentelemetry.io/otel/trace v1.42.0 h1:OUCgIPt+mzOnaUTpOQcBiM/PLQ/Op7oq6g4LenLmOYY=
go.opentelemetry.io/otel/trace v1.42.0/go.mod h1:f3K9S+IFqnumBkKhRJMeaZeNk9epyhnCmQh/EysQCdc=
golang.org/x/crypto v0.49.0 h1:+Ng2ULVvLHnJ/ZFEq4KdcDd/cfjrrjjNSXNzxg0Y4U4=
golang.org/x/crypto v0.49.0/go.mod h1:ErX4dUh2UM+CFYiXZRTcMpEcN8b/1gxEuv3nODoYtCA=
golang.org/x/net v0.52.0 h1:He/TN1l0e4mmR3QqHMT2Xab3Aj3L9qjbhRm78/6jrW0=
golang.org/x/net v0.52.0/go.mod h1:R1MAz7uMZxVMualyPXb+VaqGSa3LIaUqk0eEt3w36Sw=
golang.org/x/oauth2 v0.36.0 h1:peZ/1z27fi9hUOFCAZaHyrpWG5lwe0RJEEEeH0ThlIs=
golang.org/x/oauth2 v0.36.0/go.mod h1:YDBUJMTkDnJS+A4BP4eZBjCqtokkg1hODuPjwiGPO7Q=
golang.org/x/sync v0.20.0 h1:e0PTpb7pjO8GAtTs2dQ6jYa5BWYlMuX047Dco/pItO4=
golang.org/x/sync v0.20.0/go.mod h1:9xrNwdLfx4jkKbNva9FpL6vEN7evnE43NNNJQ2LF3+0=
golang.org/x/sys v0.42.0 h1:omrd2nAlyT5ESRdCLYdm3+fMfNFE/+Rf4bDIQImRJeo=
golang.org/x/sys v0.42.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
golang.org/x/text v0.35.0 h1:JOVx6vVDFokkpaq1AEptVzLTpDe9KGpj5tR4/X+ybL8=
golang.org/x/text v0.35.0/go.mod h1:khi/HExzZJ2pGnjenulevKNX1W67CUy0AsXcNubPGCA=
gonum.org/v1/gonum v0.16.0 h1:5+ul4Swaf3ESvrOnidPp4GZbzf0mxVQpDCYUQE7OJfk=
gonum.org/v1/gonum v0.16.0/go.mod h1:fef3am4MQ93R2HHpKnLk4/Tbh/s0+wqD5nfa6Pnwy4E=
google.golang.org/api v0.273.1 h1:L7G/TmpAMz0nKx/ciAVssVmWQiOF6+pOuXeKrWVsquY=
google.golang.org/api v0.273.1/go.mod h1:JbAt7mF+XVmWu6xNP8/+CTiGH30ofmCmk9nM8d8fHew=
google.golang.org/genproto/googleapis/rpc v0.0.0-20260319201613-d00831a3d3e7 h1:ndE4FoJqsIceKP2oYSnUZqhTdYufCYYkqwtFzfrhI7w=
google.golang.org/genproto/googleapis/rpc v0.0.0-20260319201613-d00831a3d3e7/go.mod h1:4Hqkh8ycfw05ld/3BWL7rJOSfebL2Q+DVDeRgYgxUU8=
google.golang.org/grpc v1.79.3 h1:sybAEdRIEtvcD68Gx7dmnwjZKlyfuc61Dyo9pGXXkKE=
google.golang.org/grpc v1.79.3/go.mod h1:KmT0Kjez+0dde/v2j9vzwoAScgEPx/Bw1CYChhHLrHQ=
google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

package sample

import (
	"bytes"
	"context"
	"errors"
	"io"
	"net/http"
	"net/url"

	"google.golang.org/api/googleapi"
	"google.golang.org/api/option"
	htransport "google.golang.org/api/transport/http"
)

// BuildUnauthenticatedClient creates an HTTP client and resolves the configured endpoint
// using google.golang.org/api/option and google.golang.org/api/transport/http.
func BuildUnauthenticatedClient(ctx context.Context, endpoint string) (*http.Client, string, error) {
	return htransport.NewClient(
		ctx,
		option.WithEndpoint(endpoint),
		option.WithoutAuthentication(),
	)
}

// BuildRequestURL expands URI template parameters and attaches a fields query parameter
// using google.golang.org/api/googleapi.
func BuildRequestURL(baseTemplate string, params map[string]string, fields []googleapi.Field) (string, error) {
	u, err := url.Parse(baseTemplate)
	if err != nil {
		return "", err
	}
	googleapi.Expand(u, params)
	if len(fields) > 0 {
		q := u.Query()
		q.Set("fields", googleapi.CombineFields(fields))
		u.RawQuery = q.Encode()
	}
	return u.String(), nil
}

// InspectResponse validates an HTTP response with googleapi.CheckResponse and extracts
// the structured *googleapi.Error when the response indicates a failure.
func InspectResponse(statusCode int, body []byte) (*googleapi.Error, error) {
	header := make(http.Header)
	header.Set("Content-Type", "application/json")
	res := &http.Response{
		StatusCode: statusCode,
		Header:     header,
		Body:       io.NopCloser(bytes.NewReader(body)),
	}
	defer googleapi.CloseBody(res)

	err := googleapi.CheckResponse(res)
	if err == nil {
		return nil, nil
	}
	var apiErr *googleapi.Error
	if errors.As(err, &apiErr) {
		return apiErr, err
	}
	return nil, err
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:golang/google.golang.org/api@v0.273.1",
  "kind": "HOW",
  "packages": [
    "pkg:golang/google.golang.org/api@v0.273.1"
  ]
}

package main

import (
	"context"
	"fmt"
	"os"

	"sample"

	"google.golang.org/api/googleapi"
)

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

func main() {
	ctx := context.Background()

	// 1. Verify option.WithEndpoint and option.WithoutAuthentication via transport/http.NewClient
	client, endpoint, err := sample.BuildUnauthenticatedClient(ctx, "https://example.com/custom/v1")
	if err != nil {
		fail("BuildUnauthenticatedClient returned error: %v", err)
	}
	if client == nil {
		fail("expected non-nil *http.Client")
	}
	if endpoint != "https://example.com/custom/v1" {
		fail("expected endpoint https://example.com/custom/v1, got %q", endpoint)
	}

	// 2. Verify googleapi.Expand and googleapi.CombineFields
	builtURL, err := sample.BuildRequestURL(
		"https://example.com/v1/projects/{project}/datasets/{dataset}",
		map[string]string{"project": "demo-proj", "dataset": "ds-1"},
		[]googleapi.Field{"id", "name", "tables(tableId)"},
	)
	if err != nil {
		fail("BuildRequestURL returned error: %v", err)
	}
	expectedURL := "https://example.com/v1/projects/demo-proj/datasets/ds-1?fields=id%2Cname%2Ctables%28tableId%29"
	if builtURL != expectedURL {
		fail("expected URL %q, got %q", expectedURL, builtURL)
	}

	// 3. Verify googleapi.CheckResponse succeeds on HTTP 200
	apiErr, err := sample.InspectResponse(200, []byte(`{"status":"ok"}`))
	if err != nil || apiErr != nil {
		fail("expected nil error on 200 OK, got apiErr=%v err=%v", apiErr, err)
	}

	// 4. Verify googleapi.CheckResponse parses structured JSON error into *googleapi.Error
	errPayload := []byte(`{"error":{"code":404,"message":"resource not found","errors":[{"reason":"notFound","message":"resource not found"}]}}`)
	apiErr, err = sample.InspectResponse(404, errPayload)
	if err == nil {
		fail("expected non-nil error on HTTP 404")
	}
	if apiErr == nil {
		fail("expected *googleapi.Error on HTTP 404, got %T", err)
	}
	if apiErr.Code != 404 {
		fail("expected apiErr.Code == 404, got %d", apiErr.Code)
	}
	if apiErr.Message != "resource not found" {
		fail("expected apiErr.Message == %q, got %q", "resource not found", apiErr.Message)
	}
	if len(apiErr.Errors) != 1 || apiErr.Errors[0].Reason != "notFound" {
		fail("expected 1 ErrorItem with reason notFound, got %+v", apiErr.Errors)
	}

	fmt.Println("PASS")
}