github.com/aws/aws-sdk-go-v2 v1.47.0: aws.CredentialsCache

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/aws/aws-sdk-go-v2/aws.CredentialsCache in pkg:golang/github.com/aws/aws-sdk-go-v2@v1.47.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/aws/aws-sdk-go-v2@v1.47.0
Demonstrate these symbols/APIs:
  - github.com/aws/aws-sdk-go-v2/aws.CredentialsCache

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:sha256:8f068e97731218a5b227145ab31468ef6b7610c3555165248264b2af5c0a1403","contract":["aws.NewCredentialsCache constructs a CredentialsCache wrapping a CredentialsProvider","CredentialsCache.Retrieve returns cached credentials without calling the underlying provider on subsequent calls","CredentialsCache.Invalidate clears cached credentials so the next Retrieve queries the underlying provider","CredentialsCache.IsCredentialsProvider checks if wrapped provider matches target type","CredentialsCache with ExpiryWindow refreshes credentials when expiration falls within window","CredentialsCache.Retrieve propagates errors returned by the underlying provider"],"goal":"verify github.com/aws/aws-sdk-go-v2/aws.CredentialsCache in pkg:golang/github.com/aws/aws-sdk-go-v2@v1.47.0","kind":"HOW","packages":["pkg:golang/github.com/aws/aws-sdk-go-v2@v1.47.0"],"schemaVersion":1,"symbols":["github.com/aws/aws-sdk-go-v2/aws.CredentialsCache"]},"contractCommand":["go","run","./test"],"environment":{"arch":"amd64","compiler":"go","compilerVersion":"1.26.6","distro":"ubuntu","ecosystem":"golang","language":"go","languageVersion":"1.26.6","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","packageManagerVersion":"1.26.6","runtime":"go","runtimeVersion":"1.26.6","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/github.com/aws/aws-sdk-go-v2@v1.47.0"],"schemaVersion":1,"subject":"pkg:golang/github.com/aws/aws-sdk-go-v2@v1.47.0","symbols":["github.com/aws/aws-sdk-go-v2/aws.CredentialsCache"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require github.com/aws/aws-sdk-go-v2 v1.47.0

require github.com/aws/smithy-go v1.28.5 // indirect

github.com/aws/aws-sdk-go-v2 v1.47.0 h1:0jsHallhJCeaU0Ko48c/3FK1ctOQ7NpzggxriJOQ8MQ=
github.com/aws/aws-sdk-go-v2 v1.47.0/go.mod h1:bttEH6JqnUL8LepvDVfdrds/fZ5bCIxzpe3abyUrhDU=
github.com/aws/aws-sdk-go-v2 v1.47.3 h1:HRoT/MkNi3bjO5xF4dCzLzvVmkvRGHj3/cLINDnJejk=
github.com/aws/aws-sdk-go-v2 v1.47.3/go.mod h1:xSl+OSI5ZUw6bSMupWc218zE5Pl+65MCCu3ySWFY99A=
github.com/aws/smithy-go v1.28.5 h1:OqbqKtzY9NUnr2yAe9+hiTdFb20tNaK/lI0PMOGXX9k=
github.com/aws/smithy-go v1.28.5/go.mod h1:YE2RhdIuDbA5E5bTdciG9KrW3+TiEONeUWCqxX9i1Fc=

package main

import (
	"context"
	"fmt"
	"time"

	"github.com/aws/aws-sdk-go-v2/aws"
)

type staticProvider struct {
	creds aws.Credentials
}

func (p *staticProvider) Retrieve(ctx context.Context) (aws.Credentials, error) {
	return p.creds, nil
}

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

	provider := &staticProvider{
		creds: aws.Credentials{
			AccessKeyID:     "mock-access-key-id",
			SecretAccessKey: "mock-secret-access-key",
			SessionToken:    "mock-session-token",
			Source:          "StaticCredentials",
			CanExpire:       true,
			Expires:         time.Now().Add(15 * time.Minute),
		},
	}

	cache := aws.NewCredentialsCache(provider, func(options *aws.CredentialsCacheOptions) {
		options.ExpiryWindow = 2 * time.Minute
	})

	creds, err := cache.Retrieve(ctx)
	if err != nil {
		fmt.Printf("failed to retrieve credentials: %v\n", err)
		return
	}

	fmt.Printf("retrieved credentials from cache (source: %s, hasKeys: %t)\n", creds.Source, creds.HasKeys())

	cache.Invalidate()
	fmt.Println("cache invalidated successfully")
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/aws/aws-sdk-go-v2/aws.CredentialsCache in pkg:golang/github.com/aws/aws-sdk-go-v2@v1.47.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/aws/aws-sdk-go-v2@v1.47.0"
  ],
  "symbols": [
    "github.com/aws/aws-sdk-go-v2/aws.CredentialsCache"
  ]
}

package main

import (
	"context"
	"errors"
	"fmt"
	"os"
	"sync/atomic"
	"time"

	"github.com/aws/aws-sdk-go-v2/aws"
)

type staticProvider struct {
	creds aws.Credentials
}

func (s staticProvider) Retrieve(ctx context.Context) (aws.Credentials, error) {
	return s.creds, nil
}

type countingProvider struct {
	count atomic.Int64
	creds aws.Credentials
}

func (c *countingProvider) Retrieve(ctx context.Context) (aws.Credentials, error) {
	c.count.Add(1)
	return c.creds, nil
}

type errorProvider struct {
	err error
}

func (e errorProvider) Retrieve(ctx context.Context) (aws.Credentials, error) {
	return aws.Credentials{}, e.err
}

func main() {
	if err := runContract(); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: %v\n", err)
		os.Exit(1)
	}
	fmt.Println("PASS: all contract assertions satisfied")
}

func runContract() error {
	ctx := context.Background()

	// 1. aws.NewCredentialsCache constructs a CredentialsCache wrapping a CredentialsProvider
	baseProvider := staticProvider{
		creds: aws.Credentials{
			AccessKeyID:     "mock-key-1",
			SecretAccessKey: "mock-secret-1",
			SessionToken:    "mock-token-1",
			Source:          "StaticTest",
		},
	}
	cache := aws.NewCredentialsCache(baseProvider)
	if cache == nil {
		return fmt.Errorf("NewCredentialsCache returned nil")
	}

	// 2. CredentialsCache.Retrieve returns cached credentials without calling the underlying provider on subsequent calls
	counter := &countingProvider{
		creds: aws.Credentials{
			AccessKeyID:     "mock-cached-key",
			SecretAccessKey: "mock-cached-secret",
			Source:          "CountingProvider",
			CanExpire:       true,
			Expires:         time.Now().Add(2 * time.Hour),
		},
	}
	countingCache := aws.NewCredentialsCache(counter)
	c1, err := countingCache.Retrieve(ctx)
	if err != nil {
		return fmt.Errorf("countingCache first Retrieve failed: %w", err)
	}
	c2, err := countingCache.Retrieve(ctx)
	if err != nil {
		return fmt.Errorf("countingCache second Retrieve failed: %w", err)
	}
	if c1.AccessKeyID != "mock-cached-key" || c2.AccessKeyID != "mock-cached-key" {
		return fmt.Errorf("retrieved credentials mismatch")
	}
	if calls := counter.count.Load(); calls != 1 {
		return fmt.Errorf("expected 1 call to underlying provider, got %d", calls)
	}

	// 3. CredentialsCache.Invalidate clears cached credentials so the next Retrieve queries the underlying provider
	countingCache.Invalidate()
	c3, err := countingCache.Retrieve(ctx)
	if err != nil {
		return fmt.Errorf("countingCache third Retrieve after Invalidate failed: %w", err)
	}
	if c3.AccessKeyID != "mock-cached-key" {
		return fmt.Errorf("unexpected credentials after Invalidate")
	}
	if calls := counter.count.Load(); calls != 2 {
		return fmt.Errorf("expected 2 calls to underlying provider after Invalidate, got %d", calls)
	}

	// 4. CredentialsCache.IsCredentialsProvider checks if wrapped provider matches target type
	if !countingCache.IsCredentialsProvider(&countingProvider{}) {
		return fmt.Errorf("expected IsCredentialsProvider to match &countingProvider{}")
	}
	if countingCache.IsCredentialsProvider(staticProvider{}) {
		return fmt.Errorf("expected IsCredentialsProvider to not match staticProvider{}")
	}

	// 5. CredentialsCache with ExpiryWindow refreshes credentials when expiration falls within window
	refreshCounter := &countingProvider{
		creds: aws.Credentials{
			AccessKeyID:     "expiring-key",
			SecretAccessKey: "expiring-secret",
			Source:          "RefreshProvider",
			CanExpire:       true,
			Expires:         time.Now().Add(30 * time.Second),
		},
	}
	windowCache := aws.NewCredentialsCache(refreshCounter, func(options *aws.CredentialsCacheOptions) {
		options.ExpiryWindow = 5 * time.Minute
	})
	_, err = windowCache.Retrieve(ctx)
	if err != nil {
		return fmt.Errorf("windowCache first Retrieve failed: %w", err)
	}
	_, err = windowCache.Retrieve(ctx)
	if err != nil {
		return fmt.Errorf("windowCache second Retrieve failed: %w", err)
	}
	if calls := refreshCounter.count.Load(); calls != 2 {
		return fmt.Errorf("expected 2 calls due to ExpiryWindow expiration, got %d", calls)
	}

	// 6. CredentialsCache.Retrieve propagates errors returned by the underlying provider
	expectedErr := errors.New("simulated upstream failure")
	errCache := aws.NewCredentialsCache(errorProvider{err: expectedErr})
	_, err = errCache.Retrieve(ctx)
	if err == nil {
		return fmt.Errorf("expected error from errCache, got nil")
	}
	if !errors.Is(err, expectedErr) {
		return fmt.Errorf("expected %v, got %v", expectedErr, err)
	}

	return nil
}