Check a delivery group's member beside its siblings' merges, judged by the group's controller (issue 867, ADR 0382)

A mesh-host change and a mesh-controller change that need each other could not both pass their own checks: each read the other at its base. The check now asks mesh-delivery for the group's open siblings into a base of the same name, reads each at its head merged onto its base, builds the judge from a controller sibling's merge in the isolated judge environment keyed on its inputs, and names the siblings in the verdict. With no answer from mesh-delivery the verdict says it could not learn them; a pull request with no sibling is checked as before. TestReplay867 replays the failure.

Co-Authored-By: Claude <noreply@anthropic.com>

cmd/mesh-controller/check_siblings_test.go

@@ -0,0 +1,233 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"strings"
+	"testing"
+
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
+)
+
+// **A delivery group's member is checked beside the other members' heads** (novox/hq ADR 0382 §1, §7, issue 867): the
+// controller asks mesh-delivery's `groups` once for every check it asks, and names in the ask the group's other open
+// pull requests into a base of the same name, in a repository the build seat reads beside it — mesh-lab never.
+
+const (
+	headHost       = "1111111111111111111111111111111111111111"
+	headController = "2222222222222222222222222222222222222222"
+	headSDK        = "3333333333333333333333333333333333333333"
+	headLab        = "4444444444444444444444444444444444444444"
+	headHq         = "5555555555555555555555555555555555555555"
+)
+
+func theCoreOnTheGitSeat() []inventory.Entry {
+	onSeat := func(module, repository string) inventory.Entry {
+		e := fromRepo(module, repository, "")
+		e.Source.Seat = "git"
+		return e
+	}
+	nats := onSeat("nats", "novox/mesh-catalog")
+	nats.Source.Path = "modules/nats"
+	held := catalogue.Manifest{Module: "mesh-delivery", Claims: []catalogue.Claim{{Name: catalogue.DeliverySeat, Scope: catalogue.ScopeMesh}}}
+	return []inventory.Entry{onSeat("mesh-controller", "novox/mesh-controller"), onSeat("mesh-host", "novox/mesh-host"),
+		onSeat("node-tools", "novox/mesh-tools"), nats, {Manifest: held, On: []string{"anchor"}}}
+}
+
+func besideTheCore() map[string]link.CheckedOut {
+	return map[string]link.CheckedOut{"mesh-controller": {Repository: "c"}, "mesh-host": {Repository: "h"},
+		"mesh-tools": {Repository: "t"}, "mesh-catalog": {Repository: "k"}, "mesh-sdk": {Repository: "s"}, "mesh-lab": {Repository: "l"}}
+}
+
+func member(repository string, number int, head, base string, open bool) memberLine {
+	return memberLine{ID: repository + "@" + head[:12], Repository: repository, State: "checked", Number: number, Head: head,
+		Base: base, Open: open}
+}
+
+func group(id string, members ...memberLine) groupsLine {
+	line := groupsLine{ID: id, Details: members}
+	for _, m := range members {
+		line.Members = append(line.Members, m.ID+" ("+m.State+")")
+	}
+	return line
+}
+
+func TestASiblingIsTheGroupsOtherOpenPullRequestIntoABaseOfTheSameName(t *testing.T) {
+	entries := theCoreOnTheGitSeat()
+	pull := link.PullUpdated{Owner: "novox", Repo: "mesh-host", Number: 114, Base: "main", Head: "feat/x", Commit: headHost}
+	for _, c := range []struct {
+		what    string
+		lines   []groupsLine
+		want    []string
+		unknown string
+	}{
+		{"the other member, open, same base", []groupsLine{group("feat/x",
+			member("novox/mesh-host", 114, headHost, "main", true), member("novox/mesh-controller", 346, headController, "main", true))},
+			[]string{"mesh-controller=novox/mesh-controller#346@" + headController + " onto main"}, ""},
+		{"a member into a base of another name is not one", []groupsLine{group("feat/x",
+			member("novox/mesh-host", 114, headHost, "main", true), member("novox/mesh-controller", 346, headController, "release", true))},
+			nil, ""},
+		{"a member not open (merged or closed) is not one", []groupsLine{group("feat/x",
+			member("novox/mesh-host", 114, headHost, "main", true), member("novox/mesh-controller", 346, headController, "main", false))},
+			nil, ""},
+		{"mesh-lab is never one", []groupsLine{group("feat/x",
+			member("novox/mesh-host", 114, headHost, "main", true), member("novox/mesh-lab", 5, headLab, "main", true))},
+			nil, ""},
+		{"a repository the check reads nothing of is not one", []groupsLine{group("feat/x",
+			member("novox/mesh-host", 114, headHost, "main", true), member("novox/hq", 9, headHq, "main", true))},
+			nil, ""},
+		{"mesh-sdk, read beside the controller, is one", []groupsLine{group("feat/x",
+			member("novox/mesh-host", 114, headHost, "main", true), member("novox/mesh-sdk", 7, headSDK, "main", true))},
+			[]string{"mesh-sdk=novox/mesh-sdk#7@" + headSDK + " onto main"}, ""},
+		{"another group is none of its business", []groupsLine{group("feat/y",
+			member("novox/mesh-host", 114, headHost, "main", true), member("novox/mesh-controller", 346, headController, "main", true))},
+			nil, ""},
+		{"a group of its own alone has none", []groupsLine{group("feat/x", member("novox/mesh-host", 114, headHost, "main", true))},
+			nil, ""},
+		{"an older mesh-delivery names no heads", []groupsLine{{ID: "feat/x",
+			Members: []string{"novox/mesh-host@111111111111 (checked)", "novox/mesh-controller@222222222222 (checked)"}}},
+			nil, "without their heads and bases"},
+		{"a member without its base", []groupsLine{group("feat/x",
+			member("novox/mesh-host", 114, headHost, "main", true), member("novox/mesh-controller", 346, headController, "", true))},
+			nil, "without its head or base"},
+		{"a head that is no commit", []groupsLine{group("feat/x",
+			member("novox/mesh-host", 114, headHost, "main", true), member("novox/mesh-controller", 346, headController[:12]+"zzzzzzzzzzzzzzzzzzzzzzzzzzzz", "main", true))},
+			nil, "not a whole commit"},
+	} {
+		got, unknown := siblingsFor(pull, entries, besideTheCore(), c.lines)
+		var said []string
+		for _, s := range got {
+			said = append(said, s.Dir+"="+s.Repository+"#"+itoa(s.Number)+"@"+s.Head+" onto "+s.Base)
+		}
+		if strings.Join(said, ";") != strings.Join(c.want, ";") {
+			t.Errorf("%s: siblings %v, wanted %v", c.what, said, c.want)
+		}
+		if (c.unknown == "") != (unknown == "") || !strings.Contains(unknown, c.unknown) {
+			t.Errorf("%s: could not learn %q, wanted %q", c.what, unknown, c.unknown)
+		}
+	}
+	// A pull request into a release branch has siblings into the release branch of the same name (ADR 0358 §1).
+	release := pull
+	release.Base = "feat/57"
+	lines := []groupsLine{group("feat/x", member("novox/mesh-host", 114, headHost, "feat/57", true),
+		member("novox/mesh-controller", 346, headController, "feat/57", true), member("novox/mesh-tools", 8, headLab, "main", true))}
+	if got, _ := siblingsFor(release, entries, besideTheCore(), lines); len(got) != 1 || got[0].Dir != "mesh-controller" {
+		t.Errorf("into a release branch: %+v", got)
+	}
+	// A pull request on no head branch is in no group.
+	pull.Head = ""
+	if got, unknown := siblingsFor(pull, entries, besideTheCore(), lines); got != nil || unknown != "" {
+		t.Errorf("no head branch: %+v %q", got, unknown)
+	}
+}
+
+func itoa(n int) string { b, _ := json.Marshal(n); return string(b) }
+
+// Every check asks mesh-delivery's `groups` once; the ask names the sibling's repository, head and base.
+func TestEveryCheckAsksMeshDeliveryOnceAndNamesItsSiblings(t *testing.T) {
+	entries := theCoreOnTheGitSeat()
+	asked := 0
+	was := groupsAsked
+	t.Cleanup(func() { groupsAsked = was })
+	groupsAsked = func(_ context.Context, held bool) ([]groupsLine, error) {
+		asked++
+		if !held {
+			t.Error("the seat is held, yet it was asked as not held")
+		}
+		return []groupsLine{group("feat/x", member("novox/mesh-host", 114, headHost, "main", true),
+			member("novox/mesh-controller", 346, headController, "main", true))}, nil
+	}
+	request := link.BuildRequest{Check: &link.CheckRequest{Owner: "novox", Repo: "mesh-host", Base: "main", Beside: besideTheCore()}}
+	withSiblings(t.Context(), &request, link.PullUpdated{Owner: "novox", Repo: "mesh-host", Base: "main", Head: "feat/x"}, entries)
+	if asked != 1 {
+		t.Fatalf("mesh-delivery was asked %d times for one check", asked)
+	}
+	want := link.CheckSibling{Repository: "novox/mesh-controller", Number: 346, Head: headController, Base: "main", Dir: "mesh-controller"}
+	if got := request.Check.Siblings; len(got) != 1 || got[0] != want || request.Check.SiblingsUnknown != "" {
+		t.Fatalf("the ask names siblings %+v, unknown %q", got, request.Check.SiblingsUnknown)
+	}
+	body, _ := json.Marshal(request.Check)
+	if !strings.Contains(string(body), `"siblings":[{"repository":"novox/mesh-controller","number":346,"head":"`+headController+
+		`","base":"main","dir":"mesh-controller"}]`) {
+		t.Fatalf("on the wire: %s", body)
+	}
+}
+
+// When mesh-delivery does not answer in time (or is not held, or answered without the fields), the check reads no
+// sibling and its request says it could not learn them, so a fix to mesh-delivery is still checked without it.
+func TestWhenMeshDeliveryDoesNotAnswerTheCheckReadsNoSiblingAndSaysSo(t *testing.T) {
+	was := groupsAsked
+	t.Cleanup(func() { groupsAsked = was })
+	for _, c := range []struct {
+		what string
+		err  error
+		held bool
+	}{{"it did not answer", context.DeadlineExceeded, true}, {"nothing serves it", errors.New("nothing serves mesh-delivery.groups"), true},
+		{"no holder on record", errors.New("no holder of mesh-delivery is on record to say it"), false}} {
+		entries := theCoreOnTheGitSeat()
+		if !c.held {
+			entries = entries[:4]
+		}
+		groupsAsked = func(_ context.Context, held bool) ([]groupsLine, error) {
+			if held != c.held {
+				t.Errorf("%s: held %v", c.what, held)
+			}
+			return nil, c.err
+		}
+		request := link.BuildRequest{Check: &link.CheckRequest{Owner: "novox", Repo: "mesh-host", Base: "main", Beside: besideTheCore()}}
+		withSiblings(t.Context(), &request, link.PullUpdated{Owner: "novox", Repo: "mesh-host", Base: "main", Head: "feat/x"}, entries)
+		if len(request.Check.Siblings) != 0 || !strings.Contains(request.Check.SiblingsUnknown, c.err.Error()) ||
+			!strings.Contains(request.Check.SiblingsUnknown, "reads no siblings") {
+			t.Errorf("%s: siblings %+v, unknown %q", c.what, request.Check.Siblings, request.Check.SiblingsUnknown)
+		}
+	}
+}
+
+// **A pull request for which mesh-delivery answered and named no sibling is asked exactly as before** (ADR 0382 §7):
+// byte for byte the request it was without the rule.
+func TestAPullRequestWithNoSiblingIsAskedByteForByteAsBefore(t *testing.T) {
+	entries := theCoreOnTheGitSeat()
+	was := groupsAsked
+	t.Cleanup(func() { groupsAsked = was })
+	for _, answer := range [][]groupsLine{nil, {group("feat/other", member("novox/mesh-controller", 346, headController, "main", true))},
+		{group("feat/x", member("novox/mesh-host", 114, headHost, "main", true), member("novox/hq", 3, headHq, "main", true))}} {
+		groupsAsked = func(context.Context, bool) ([]groupsLine, error) { return answer, nil }
+		build := func() link.BuildRequest {
+			return link.BuildRequest{ID: "build-1", Repository: "r", Ref: headHost, Check: &link.CheckRequest{Owner: "novox",
+				Repo: "mesh-host", Number: 114, Base: "main", Beside: besideTheCore(), Modules: []string{"mesh-host"}, Judge: "validator"}}
+		}
+		before, _ := json.Marshal(build())
+		after := build()
+		withSiblings(t.Context(), &after, link.PullUpdated{Owner: "novox", Repo: "mesh-host", Base: "main", Head: "feat/x"}, entries)
+		got, _ := json.Marshal(after)
+		if string(before) != string(got) {
+			t.Fatalf("the request changed:\nbefore %s\nafter  %s", before, got)
+		}
+	}
+}
+
+// What the build seat's verdict says of its siblings reaches the forge's holder in the controller's `checked`.
+func TestTheVerdictCarriesTheSiblingsAndWhereTheJudgeCameFrom(t *testing.T) {
+	read := []link.CheckSibling{{Repository: "novox/mesh-controller", Number: 346, Head: headController, Base: "main", BaseCommit: headHost}}
+	c := checkedOf(link.BuildResult{ID: "b", Ref: headHost, Checked: &link.CheckRequest{Owner: "novox", Repo: "mesh-host", Number: 114},
+		Check: &link.CheckOutcome{Verdict: "pass", Summary: "ok", Siblings: read, JudgeFrom: "sibling novox/mesh-controller#346 merge abc",
+			Validator: "the change's own validator"}})
+	if len(c.Siblings) != 1 || c.Siblings[0] != read[0] || c.JudgeFrom == "" || c.Validator == "" {
+		t.Fatalf("the verdict says %+v", c)
+	}
+	body, _ := json.Marshal(c)
+	for _, want := range []string{`"siblings":[{"repository":"novox/mesh-controller","number":346,"head":"` + headController +
+		`","base":"main","base_commit":"` + headHost + `"}]`, `"judge_from":"sibling novox/mesh-controller#346 merge abc"`} {
+		if !strings.Contains(string(body), want) {
+			t.Fatalf("the verdict lacks %s:\n%s", want, body)
+		}
+	}
+	unknown := checkedOf(link.BuildResult{ID: "b", Check: &link.CheckOutcome{Verdict: "pass", SiblingsUnknown: "mesh-delivery did not answer"}})
+	if body, _ := json.Marshal(unknown); !strings.Contains(string(body), `"siblings_unknown":"mesh-delivery did not answer"`) ||
+		strings.Contains(string(body), `"siblings":`) {
+		t.Fatalf("the verdict that could not learn them says %s", body)
+	}
+}