handle large item client redirects (#3350)

adds the khttp redirectMiddleware to the http wrapper used for large item downloads, to ensure that proxy servers and other 3xx class responses appropriately follow their redirection.

---

#### Does this PR need a docs update or release note?

- [x] ✅ Yes, it's included

#### Type of change

- [x] 🐛 Bugfix

#### Issue(s)

* #3344

#### Test Plan

- [x] ⚡ Unit test
- [x] 💚 E2E

CHANGELOG.md

@@ -17,6 +17,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Improve restore time on large restores by optimizing how items are loaded from the remote repository.
 - Remove exchange item filtering based on m365 item ID via the CLI.
 - OneDrive backups no longer include a user's non-default drives.
+- OneDrive and SharePoint file downloads will properly redirect from 3xx responses.
 
 ## [v0.7.0] (beta) - 2023-05-02
 

src/internal/connector/graph/http_wrapper.go

@@ -140,13 +140,20 @@ func defaultTransport() http.RoundTripper {
 }
 
 func internalMiddleware(cc *clientConfig) []khttp.Middleware {
-	return []khttp.Middleware{
+	mw := []khttp.Middleware{
 		&RetryMiddleware{
 			MaxRetries: cc.maxRetries,
 			Delay:      cc.minDelay,
 		},
+		khttp.NewRedirectHandler(),
 		&LoggingMiddleware{},
 		&ThrottleControlMiddleware{},
 		&MetricsMiddleware{},
 	}
+
+	if len(cc.appendMiddleware) > 0 {
+		mw = append(mw, cc.appendMiddleware...)
+	}
+
+	return mw
 }

src/internal/connector/graph/http_wrapper_test.go

@@ -2,9 +2,11 @@ package graph
 
 import (
 	"net/http"
+	"strings"
 	"testing"
 
 	"github.com/alcionai/clues"
+	khttp "github.com/microsoft/kiota-http-go"
 	"github.com/stretchr/testify/require"
 	"github.com/stretchr/testify/suite"
 
@@ -43,3 +45,70 @@ func (suite *HTTPWrapperIntgSuite) TestNewHTTPWrapper() {
 	require.NotNil(t, resp)
 	require.Equal(t, http.StatusOK, resp.StatusCode)
 }
+
+type mwForceResp struct {
+	err       error
+	resp      *http.Response
+	alternate func(*http.Request) (bool, *http.Response, error)
+}
+
+func (mw *mwForceResp) Intercept(
+	pipeline khttp.Pipeline,
+	middlewareIndex int,
+	req *http.Request,
+) (*http.Response, error) {
+	ok, r, e := mw.alternate(req)
+	if ok {
+		return r, e
+	}
+
+	return mw.resp, mw.err
+}
+
+type HTTPWrapperUnitSuite struct {
+	tester.Suite
+}
+
+func TestHTTPWrapperUnitSuite(t *testing.T) {
+	suite.Run(t, &HTTPWrapperUnitSuite{Suite: tester.NewUnitSuite(t)})
+}
+
+func (suite *HTTPWrapperUnitSuite) TestNewHTTPWrapper_redirectMiddleware() {
+	ctx, flush := tester.NewContext()
+	defer flush()
+
+	var (
+		t    = suite.T()
+		uri  = "https://graph.microsoft.com"
+		path = "/fnords/beaux/regard"
+		url  = uri + path
+	)
+
+	// can't use gock for this, or else it'll short-circuit the transport,
+	// and thus skip all the middleware
+	hdr := http.Header{}
+	hdr.Set("Location", "localhost:99999999/smarfs")
+	toResp := &http.Response{
+		StatusCode: 302,
+		Header:     hdr,
+	}
+	mwResp := mwForceResp{
+		resp: toResp,
+		alternate: func(req *http.Request) (bool, *http.Response, error) {
+			if strings.HasSuffix(req.URL.String(), "smarfs") {
+				return true, &http.Response{StatusCode: http.StatusOK}, nil
+			}
+
+			return false, nil, nil
+		},
+	}
+
+	hw := NewHTTPWrapper(appendMiddleware(&mwResp))
+
+	resp, err := hw.Request(ctx, http.MethodGet, url, nil, nil)
+
+	require.NoError(t, err, clues.ToCore(err))
+	require.NotNil(t, resp)
+	// require.Equal(t, 1, calledCorrectly, "test server was called with expected path")
+	require.Equal(t, http.StatusOK, resp.StatusCode)
+}

src/internal/connector/graph/service.go

@@ -173,6 +173,8 @@ type clientConfig struct {
 	// The minimum delay in seconds between retries
 	minDelay           time.Duration
 	overrideRetryCount bool
+
+	appendMiddleware []khttp.Middleware
 }
 
 type Option func(*clientConfig)
@@ -225,6 +227,14 @@ func MinimumBackoff(dur time.Duration) Option {
 	}
 }
 
+func appendMiddleware(mw ...khttp.Middleware) Option {
+	return func(c *clientConfig) {
+		if len(mw) > 0 {
+			c.appendMiddleware = mw
+		}
+	}
+}
+
 // ---------------------------------------------------------------------------
 // Middleware Control
 // ---------------------------------------------------------------------------
@@ -257,5 +267,9 @@ func kiotaMiddlewares(
 		&MetricsMiddleware{},
 	}...)
 
+	if len(cc.appendMiddleware) > 0 {
+		mw = append(mw, cc.appendMiddleware...)
+	}
+
 	return mw
 }