internal/pkg: expose underlying reader

This will be fully implemented in httpArtifact in a future commit.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/pkg/net.go

@@ -1,6 +1,7 @@
 package pkg
 
 import (
+	"bytes"
 	"context"
 	"crypto/sha512"
 	"fmt"
@@ -34,13 +35,13 @@ type httpArtifact struct {
 var _ KnownChecksum = new(httpArtifact)
 var _ fmt.Stringer = new(httpArtifact)
 
-// NewHTTPGet returns a new [File] backed by the supplied client. A GET request
-// is set up for url. If c is nil, [http.DefaultClient] is used instead.
+// NewHTTPGet returns a new [FileArtifact] backed by the supplied client. A GET
+// request is set up for url. If c is nil, [http.DefaultClient] is used instead.
 func NewHTTPGet(
 	c *http.Client,
 	url string,
 	checksum Checksum,
-) File {
+) FileArtifact {
 	if c == nil {
 		c = http.DefaultClient
 	}
@@ -103,15 +104,16 @@ func (a *httpArtifact) do(ctx context.Context) (data []byte, err error) {
 
 // Cure completes the http request and returns the resulting response body read
 // to EOF. Data does not interact with the filesystem.
-func (a *httpArtifact) Cure(ctx context.Context) (data []byte, err error) {
+func (a *httpArtifact) Cure(ctx context.Context) (r io.ReadCloser, err error) {
 	a.mu.Lock()
 	defer a.mu.Unlock()
 
 	if a.data != nil {
-		// validated by cache or a previous call to Data
-		return a.data, nil
+		// validated by cache or a previous call to Cure
+		return io.NopCloser(bytes.NewReader(a.data)), nil
 	}
 
+	var data []byte
 	if data, err = a.do(ctx); err != nil {
 		return
 	}
@@ -122,5 +124,6 @@ func (a *httpArtifact) Cure(ctx context.Context) (data []byte, err error) {
 		return nil, &ChecksumMismatchError{got, a.checksum}
 	}
 	a.data = data
+	r = io.NopCloser(bytes.NewReader(data))
 	return
 }