test: add a bunch of new tests and fixes

- do not expect specific filename, that's impl. detail
- add new fixtures, rename some, delete others
- fix byte range tests (limit is inclusive)
- dag-cbor tests with links
- content-type and content-disposition checks in all car tests
- and much more

tooling/car/unixfs.go

@@ -6,8 +6,8 @@ package car
 import (
 	"bytes"
 	"context"
+	"errors"
 	"fmt"
-	dagpb "github.com/ipld/go-codec-dagpb"
 	"io"
 	"os"
 	"path"
@@ -22,6 +22,7 @@ import (
 	"github.com/ipfs/go-cid"
 	format "github.com/ipfs/go-ipld-format"
 	"github.com/ipfs/go-unixfsnode"
+	dagpb "github.com/ipld/go-codec-dagpb"
 	"github.com/ipld/go-ipld-prime"
 	_ "github.com/ipld/go-ipld-prime/codec/cbor"
 	_ "github.com/ipld/go-ipld-prime/codec/dagcbor"
@@ -78,15 +79,27 @@ func (d *UnixfsDag) loadLinks(node format.Node) (map[string]*UnixfsDag, error) {
 }
 
 func (d *UnixfsDag) getNode(names ...string) (format.Node, error) {
-	for _, name := range names {
+	for i, name := range names {
 		node, err := d.getNode()
 		if err != nil {
 			return nil, err
 		}
 
 		if d.links == nil {
 			d.links, err = d.loadLinks(node)
-			if err != nil {
+			if errors.Is(err, uio.ErrNotADir) {
+				// Maybe it's an IPLD Link!
+				lnk, _, err := node.ResolveLink(names[i:])
+				if err != nil {
+					return nil, fmt.Errorf("node is neither a unixfs directory, or includes an ipld link: %w", err)
+				}
+				n, err := lnk.GetNode(context.Background(), d.dsvc)
+				if err != nil {
+					return nil, fmt.Errorf("found link node could not be fetched: %w", err)
+				}
+				d.node = n
+				return d.node, nil
+			} else if err != nil {
 				return nil, err
 			}
 		}
@@ -173,16 +186,6 @@ func (d *UnixfsDag) MustGetChildrenCids(names ...string) []string {
 	return cids
 }
 
-func (d *UnixfsDag) MustGetIPLDChildrenCids(names ...string) []string {
-	node := d.MustGetNode(names...)
-	lnks := node.node.Links()
-	var cids []string
-	for _, l := range lnks {
-		cids = append(cids, l.Cid.String())
-	}
-	return cids
-}
-
 // MustGetCidsInHAMT returns the cids in the HAMT at the given path. Does not include the CID of the HAMT root
 func (d *UnixfsDag) MustGetCidsInHAMT(names ...string) []string {
 	node := d.MustGetNode(names...)

tooling/helpers/car.go

@@ -29,6 +29,12 @@ func applyStandardCarResponseHeaders(t *testing.T, st test.SugarTest) test.Sugar
 		test.Header("Accept-Ranges").
 			Hint("CAR is streamed, gateway may not have the entire thing, unable to support range-requests. Partial downloads and resumes should be handled using IPLD selectors: https://github.com/ipfs/go-ipfs/issues/8769").
 			Equals("none"),
+		test.Header("Content-Type").
+			Hint("Expected content type to be application/vnd.ipld.car").
+			Contains("application/vnd.ipld.car"),
+		test.Header("Content-Disposition").
+			Hint(`Expected content disposition to be attachment; filename="*.car"`).
+			Matches(`attachment; filename=".*\.car"`),
 	)
 	return st
 }

tooling/test/sugar.go

@@ -22,8 +22,8 @@ type RequestBuilder struct {
 
 func Request() RequestBuilder {
 	return RequestBuilder{
-		Method_: "GET",
-		Query_:  make(url.Values),
+		Method_:          "GET",
+		Query_:           make(url.Values),
 		FollowRedirects_: false,
 	}
 }
@@ -116,15 +116,15 @@ func (r RequestBuilder) Clone() RequestBuilder {
 	}
 
 	return RequestBuilder{
-		Method_:               r.Method_,
-		Path_:                 r.Path_,
-		URL_:                  r.URL_,
-		Proxy_:                r.Proxy_,
-		UseProxyTunnel_:       r.UseProxyTunnel_,
-		Headers_:              clonedHeaders,
-		DoNotFollowRedirects_: r.DoNotFollowRedirects_,
-		Query_:                clonedQuery,
-		Body_:                 bytes.Clone(r.Body_),
+		Method_:          r.Method_,
+		Path_:            r.Path_,
+		URL_:             r.URL_,
+		Proxy_:           r.Proxy_,
+		UseProxyTunnel_:  r.UseProxyTunnel_,
+		Headers_:         clonedHeaders,
+		FollowRedirects_: r.FollowRedirects_,
+		Query_:           clonedQuery,
+		Body_:            bytes.Clone(r.Body_),
 	}
 }