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

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.CredentialsProviderFunc 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.CredentialsProviderFunc

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:sha256:57f0edb52adc0fe3d10e60034b7b859374f800c5f4a72ce1cf36f75e5d2180bd","contract":["CredentialsProviderFunc satisfies the aws.CredentialsProvider interface and retrieves credentials successfully via Retrieve","CredentialsProviderFunc receives and respects the caller context passed to Retrieve","CredentialsProviderFunc propagates errors returned by the underlying function","CredentialsProviderFunc returns expected credential fields including access keys and token"],"goal":"verify github.com/aws/aws-sdk-go-v2/aws.CredentialsProviderFunc 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.CredentialsProviderFunc"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","language":"go","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.CredentialsProviderFunc"],"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 v1.28.1 // 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/smithy-go v1.28.1 h1:R/nXH00c8qcfCzQVELtRw+eLQWtzv+VAIEFJ1/xxXlQ=
github.com/aws/smithy-go v1.28.1/go.mod h1:YE2RhdIuDbA5E5bTdciG9KrW3+TiEONeUWCqxX9i1Fc=

package main

import (
	"context"
	"fmt"

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

func main() {
	// CredentialsProviderFunc adapts a closure to satisfy aws.CredentialsProvider
	provider := aws.CredentialsProviderFunc(func(ctx context.Context) (aws.Credentials, error) {
		return aws.Credentials{
			AccessKeyID:     "mock-access-key-id",
			SecretAccessKey: "mock-secret-access-key",
			SessionToken:    "mock-session-token",
			Source:          "CustomProviderFunc",
		}, nil
	})

	// Verify that provider satisfies the aws.CredentialsProvider interface
	var cp aws.CredentialsProvider = provider

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

	fmt.Printf("Retrieved credentials successfully for AccessKeyID: %s\n", creds.AccessKeyID)
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/aws/aws-sdk-go-v2/aws.CredentialsProviderFunc 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.CredentialsProviderFunc"
  ]
}

package main

import (
	"context"
	"errors"
	"fmt"
	"os"

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

type contextKey string

func main() {
	// Assertion 1: CredentialsProviderFunc satisfies the aws.CredentialsProvider interface and retrieves credentials successfully via Retrieve
	{
		provider := aws.CredentialsProviderFunc(func(ctx context.Context) (aws.Credentials, error) {
			return aws.Credentials{
				AccessKeyID:     "mock-access-key-id",
				SecretAccessKey: "mock-secret-access-key",
			}, nil
		})

		var cp aws.CredentialsProvider = provider
		creds, err := cp.Retrieve(context.Background())
		if err != nil {
			fmt.Fprintf(os.Stderr, "assertion 1 failed: unexpected error: %v\n", err)
			os.Exit(1)
		}
		if creds.AccessKeyID != "mock-access-key-id" {
			fmt.Fprintf(os.Stderr, "assertion 1 failed: expected AccessKeyID 'mock-access-key-id', got '%s'\n", creds.AccessKeyID)
			os.Exit(1)
		}
	}

	// Assertion 2: CredentialsProviderFunc receives and respects the caller context passed to Retrieve
	{
		var receivedCtx context.Context
		k := contextKey("test-key")
		provider := aws.CredentialsProviderFunc(func(ctx context.Context) (aws.Credentials, error) {
			receivedCtx = ctx
			if val, ok := ctx.Value(k).(string); !ok || val != "expected-val" {
				return aws.Credentials{}, errors.New("context value mismatch")
			}
			return aws.Credentials{AccessKeyID: "CTX_VALID_KEY"}, nil
		})

		ctx := context.WithValue(context.Background(), k, "expected-val")
		creds, err := provider.Retrieve(ctx)
		if err != nil {
			fmt.Fprintf(os.Stderr, "assertion 2 failed: unexpected error: %v\n", err)
			os.Exit(1)
		}
		if receivedCtx != ctx || creds.AccessKeyID != "CTX_VALID_KEY" {
			fmt.Fprintf(os.Stderr, "assertion 2 failed: context was not properly forwarded\n")
			os.Exit(1)
		}
	}

	// Assertion 3: CredentialsProviderFunc propagates errors returned by the underlying function
	{
		expectedErr := errors.New("failed to acquire token")
		provider := aws.CredentialsProviderFunc(func(ctx context.Context) (aws.Credentials, error) {
			return aws.Credentials{}, expectedErr
		})

		_, err := provider.Retrieve(context.Background())
		if err == nil {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: expected error but got nil\n")
			os.Exit(1)
		}
		if !errors.Is(err, expectedErr) {
			fmt.Fprintf(os.Stderr, "assertion 3 failed: expected %v, got %v\n", expectedErr, err)
			os.Exit(1)
		}
	}

	// Assertion 4: CredentialsProviderFunc returns expected credential fields including access keys and token
	{
		provider := aws.CredentialsProviderFunc(func(ctx context.Context) (aws.Credentials, error) {
			return aws.Credentials{
				AccessKeyID:     "KEY123",
				SecretAccessKey: "SECRET456",
				SessionToken:    "TOKEN789",
				Source:          "StaticFunc",
				CanExpire:       true,
			}, nil
		})

		creds, err := provider.Retrieve(context.Background())
		if err != nil {
			fmt.Fprintf(os.Stderr, "assertion 4 failed: unexpected error: %v\n", err)
			os.Exit(1)
		}
		if creds.AccessKeyID != "KEY123" || creds.SecretAccessKey != "SECRET456" || creds.SessionToken != "TOKEN789" || creds.Source != "StaticFunc" || !creds.CanExpire {
			fmt.Fprintf(os.Stderr, "assertion 4 failed: credential fields do not match expected values\n")
			os.Exit(1)
		}
	}

	fmt.Println("All contract assertions passed successfully.")
}