errors_test.go

package apihandler_test

import (
	"errors"
	"fmt"
	"net/http"
	"testing"

	apihandler "github.com/wickedbyte/api-handler-go"
)

// errCause is the sentinel wrapped cause used by the StatusError tests.
var errCause = errors.New("connection refused")

// detailUpstreamUnavailable is the client-safe detail shared by the
// StatusError and writer-logging tests.
const detailUpstreamUnavailable = "upstream unavailable"

func TestStatusErrorMessageWithoutCause(t *testing.T) {
	t.Parallel()

	err := apihandler.Error(http.StatusNotFound, "no such user")

	if got, want := err.Error(), "404 no such user"; got != want {
		t.Fatalf("message = %q, want %q", got, want)
	}
}

func TestStatusErrorMessageWithCause(t *testing.T) {
	t.Parallel()

	err := &apihandler.StatusError{
		Status: http.StatusBadGateway,
		Detail: detailUpstreamUnavailable,
		Err:    errCause,
	}

	if got, want := err.Error(), "502 upstream unavailable: connection refused"; got != want {
		t.Fatalf("message = %q, want %q", got, want)
	}
}

func TestStatusErrorUnwrapExposesCause(t *testing.T) {
	t.Parallel()

	err := &apihandler.StatusError{
		Status: http.StatusBadGateway,
		Detail: detailUpstreamUnavailable,
		Err:    errCause,
	}

	if !errors.Is(err, errCause) {
		t.Fatal("errors.Is did not find the wrapped cause")
	}

	if !errors.Is(errors.Unwrap(err), errCause) {
		t.Fatal("Unwrap did not return the wrapped cause")
	}
}

func TestErrorConstructsStatusError(t *testing.T) {
	t.Parallel()

	err := apihandler.Error(http.StatusConflict, "already exists")

	if err.Status != http.StatusConflict || err.Detail != "already exists" {
		t.Fatalf("err = %+v", err)
	}

	if err.HTTPStatus() != http.StatusConflict {
		t.Fatalf("HTTPStatus() = %d", err.HTTPStatus())
	}

	var statusErr *apihandler.StatusError
	if !errors.As(err, &statusErr) {
		t.Fatalf("err = %T, want *apihandler.StatusError", err)
	}

	if statusErr.Status != http.StatusConflict || statusErr.Detail != "already exists" {
		t.Fatalf("statusErr = %+v", statusErr)
	}
}

func TestErrorsAsFindsHTTPStatusThroughWrapping(t *testing.T) {
	t.Parallel()

	wrapped := fmt.Errorf("loading user: %w", apihandler.Error(http.StatusNotFound, "no such user"))

	var carrier interface{ HTTPStatus() int }
	if !errors.As(wrapped, &carrier) {
		t.Fatal("errors.As did not find the HTTPStatus carrier")
	}

	if carrier.HTTPStatus() != http.StatusNotFound {
		t.Fatalf("HTTPStatus() = %d", carrier.HTTPStatus())
	}
}