Fetch a declaration's files given by digest from the bus's object bucket, verify them and report file-references (issue 1695, ADR 0486)

mesh-sdk is pinned to fix/1694-file-references 6c857e1c025f until it merges.

internal/apply/references_test.go

@@ -0,0 +1,119 @@
+package apply
+
+import (
+	"context"
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"git.novox.be/novox/mesh-sdk/go/declaration"
+)
+
+func referenceTo(t *testing.T, path string, body []byte) *declaration.File {
+	t.Helper()
+	return &declaration.File{ID: "m.big", Type: declaration.TypeFile, Path: path,
+		Digest: declaration.DigestOf(body), Size: int64(len(body))}
+}
+
+func objects(m map[string][]byte, asked *[]string) FetchObject {
+	return func(_ context.Context, name string, limit int64) ([]byte, error) {
+		*asked = append(*asked, name)
+		b, ok := m[name]
+		if !ok {
+			return nil, errors.New("object not found")
+		}
+		return b, nil
+	}
+}
+
+func objectOf(body []byte) string {
+	name, _ := declaration.ObjectName(declaration.DigestOf(body))
+	return name
+}
+
+// 1695/AC1: both forms apply: a file by reference becomes the inline file, an inline one is left as it is.
+func TestAFileByReferenceBecomesTheInlineFile(t *testing.T) {
+	body := []byte(strings.Repeat("a line\n", 20000))
+	inline := &declaration.File{ID: "m.small", Type: declaration.TypeFile, Path: "/etc/small", Content: "x"}
+	d := &declaration.Declaration{Resources: []declaration.Resource{inline, referenceTo(t, "/nowhere/big", body)}}
+	var asked []string
+	if err := ResolveFileReferences(context.Background(), d, objects(map[string][]byte{objectOf(body): body}, &asked)); err != nil {
+		t.Fatal(err)
+	}
+	got := d.Resources[1].(*declaration.File)
+	if got.IsReference() || got.Content != string(body) || got.Path != "/nowhere/big" || d.Resources[0] != declaration.Resource(inline) {
+		t.Errorf("1695/AC1: resolved to %+v", got)
+	}
+	if len(asked) != 1 || asked[0] != objectOf(body) {
+		t.Errorf("1695/AC1: asked %v", asked)
+	}
+}
+
+// 1695/AC2: an object that differs by one byte, or in size, fails the whole resolve and gives no content.
+func TestAnObjectThatDiffersFailsTheApply(t *testing.T) {
+	body := []byte(strings.Repeat("x", 70000))
+	bad := append([]byte(nil), body...)
+	bad[3] ^= 1
+	for name, served := range map[string][]byte{"one byte": bad, "shorter": body[1:]} {
+		d := &declaration.Declaration{Resources: []declaration.Resource{referenceTo(t, "/nowhere/big", body)}}
+		var asked []string
+		err := ResolveFileReferences(context.Background(), d, objects(map[string][]byte{objectOf(body): served}, &asked))
+		if err == nil || !strings.Contains(err.Error(), "nothing was applied") {
+			t.Errorf("1695/AC2: %s: %v", name, err)
+		}
+		if !d.Resources[0].(*declaration.File).IsReference() {
+			t.Errorf("1695/AC2: %s: the reference was replaced by unverified content", name)
+		}
+	}
+}
+
+// 1695/AC3: a missing object, or a node with no bus, fails the apply naming the file.
+func TestAMissingObjectFailsTheApply(t *testing.T) {
+	body := []byte(strings.Repeat("y", 70000))
+	d := &declaration.Declaration{Resources: []declaration.Resource{referenceTo(t, "/nowhere/big", body)}}
+	var asked []string
+	if err := ResolveFileReferences(context.Background(), d, objects(nil, &asked)); err == nil ||
+		!strings.Contains(err.Error(), "m.big") || !strings.Contains(err.Error(), "declaration-files") {
+		t.Errorf("1695/AC3: missing object: %v", err)
+	}
+	if err := ResolveFileReferences(context.Background(), d, nil); err == nil || !strings.Contains(err.Error(), "no link to the bus") {
+		t.Errorf("1695/AC3: no bus: %v", err)
+	}
+}
+
+// 1695/AC4: a file already on the machine that verifies is used and nothing is fetched; one that does not is fetched.
+func TestAVerifiedFileOnTheMachineFetchesNothing(t *testing.T) {
+	body := []byte(strings.Repeat("z", 70000))
+	path := filepath.Join(t.TempDir(), "big")
+	if err := os.WriteFile(path, body, 0o644); err != nil {
+		t.Fatal(err)
+	}
+	var asked []string
+	d := &declaration.Declaration{Resources: []declaration.Resource{referenceTo(t, path, body)}}
+	if err := ResolveFileReferences(context.Background(), d, objects(nil, &asked)); err != nil || len(asked) != 0 {
+		t.Errorf("1695/AC4: err %v, asked %v", err, asked)
+	}
+	if err := os.WriteFile(path, body[:100], 0o644); err != nil {
+		t.Fatal(err)
+	}
+	d = &declaration.Declaration{Resources: []declaration.Resource{referenceTo(t, path, body)}}
+	if err := ResolveFileReferences(context.Background(), d, objects(map[string][]byte{objectOf(body): body}, &asked)); err != nil || len(asked) != 1 {
+		t.Errorf("1695/AC4: a differing file: err %v, asked %v", err, asked)
+	}
+}
+
+// 1695/AC5: binary content comes back as bytes, and two files naming one digest fetch it once.
+func TestBinaryContentAndOneFetchPerDigest(t *testing.T) {
+	body := append([]byte{0xff, 0xfe, 0x00}, []byte(strings.Repeat("b", 70000))...)
+	d := &declaration.Declaration{Resources: []declaration.Resource{referenceTo(t, "/n/a", body), referenceTo(t, "/n/b", body)}}
+	var asked []string
+	if err := ResolveFileReferences(context.Background(), d, objects(map[string][]byte{objectOf(body): body}, &asked)); err != nil {
+		t.Fatal(err)
+	}
+	a, _ := d.Resources[0].(*declaration.File).Body()
+	if d.Resources[0].(*declaration.File).Bytes == "" || string(a) != string(body) || len(asked) != 1 {
+		t.Errorf("1695/AC5: bytes %q asked %v", d.Resources[0].(*declaration.File).Bytes[:4], asked)
+	}
+}