Add framework composition runner

internal/framework/validators/validators.go

@@ -0,0 +1,64 @@
+package validators
+
+import (
+	"fmt"
+	"strings"
+
+	"gitea.maximumdirect.net/eric/notarius/internal/core/artifacts"
+	"gitea.maximumdirect.net/eric/notarius/internal/framework/contracts"
+)
+
+const (
+	ReasonApproved = "approved"
+)
+
+func Approved(candidateIndex int) contracts.ValidationDecision {
+	return contracts.ValidationDecision{
+		CandidateIndex: candidateIndex,
+		Approved:       true,
+		ReasonCode:     ReasonApproved,
+		Message:        ReasonApproved,
+	}
+}
+
+func Rejected(candidateIndex int, reasonCode string, message string) contracts.ValidationDecision {
+	return contracts.ValidationDecision{
+		CandidateIndex: candidateIndex,
+		Approved:       false,
+		ReasonCode:     strings.TrimSpace(reasonCode),
+		Message:        strings.TrimSpace(message),
+	}
+}
+
+func EnforceDecisionCardinality(candidates []artifacts.Candidate, decisions []contracts.ValidationDecision) error {
+	if len(candidates) != len(decisions) {
+		return fmt.Errorf("validator returned %d decisions for %d candidates", len(decisions), len(candidates))
+	}
+
+	expected := make(map[int]struct{}, len(candidates))
+	for _, candidate := range candidates {
+		if _, ok := expected[candidate.Index]; ok {
+			return fmt.Errorf("candidate index %d is duplicated", candidate.Index)
+		}
+		expected[candidate.Index] = struct{}{}
+	}
+
+	seen := make(map[int]struct{}, len(decisions))
+	for _, decision := range decisions {
+		if _, ok := expected[decision.CandidateIndex]; !ok {
+			return fmt.Errorf("validator returned decision for unknown candidate index %d", decision.CandidateIndex)
+		}
+		if _, ok := seen[decision.CandidateIndex]; ok {
+			return fmt.Errorf("validator returned duplicate decision for candidate index %d", decision.CandidateIndex)
+		}
+		seen[decision.CandidateIndex] = struct{}{}
+	}
+
+	for candidateIndex := range expected {
+		if _, ok := seen[candidateIndex]; !ok {
+			return fmt.Errorf("validator did not return decision for candidate index %d", candidateIndex)
+		}
+	}
+
+	return nil
+}

internal/framework/validators/validators_test.go

@@ -0,0 +1,105 @@
+package validators
+
+import (
+	"strings"
+	"testing"
+
+	"gitea.maximumdirect.net/eric/notarius/internal/core/artifacts"
+	"gitea.maximumdirect.net/eric/notarius/internal/framework/contracts"
+)
+
+func TestApproved(t *testing.T) {
+	decision := Approved(7)
+
+	if decision.CandidateIndex != 7 {
+		t.Fatalf("CandidateIndex = %d, want 7", decision.CandidateIndex)
+	}
+	if !decision.Approved {
+		t.Fatal("Approved = false, want true")
+	}
+	if decision.ReasonCode != ReasonApproved {
+		t.Fatalf("ReasonCode = %q, want %q", decision.ReasonCode, ReasonApproved)
+	}
+	if decision.Message != "approved" {
+		t.Fatalf("Message = %q, want approved", decision.Message)
+	}
+}
+
+func TestRejectedTrimsReasonAndMessage(t *testing.T) {
+	decision := Rejected(3, " invalid ", "\tmessage\n")
+
+	if decision.CandidateIndex != 3 {
+		t.Fatalf("CandidateIndex = %d, want 3", decision.CandidateIndex)
+	}
+	if decision.Approved {
+		t.Fatal("Approved = true, want false")
+	}
+	if decision.ReasonCode != "invalid" {
+		t.Fatalf("ReasonCode = %q, want invalid", decision.ReasonCode)
+	}
+	if decision.Message != "message" {
+		t.Fatalf("Message = %q, want message", decision.Message)
+	}
+}
+
+func TestEnforceDecisionCardinalityAllowsNonZeroCandidateIndices(t *testing.T) {
+	candidates := []artifacts.Candidate{{Index: 4}, {Index: 8}}
+	decisions := []contracts.ValidationDecision{Approved(8), Approved(4)}
+
+	if err := EnforceDecisionCardinality(candidates, decisions); err != nil {
+		t.Fatalf("EnforceDecisionCardinality() error = %v, want nil", err)
+	}
+}
+
+func TestEnforceDecisionCardinalityAllowsEmptyInputs(t *testing.T) {
+	if err := EnforceDecisionCardinality(nil, nil); err != nil {
+		t.Fatalf("EnforceDecisionCardinality() error = %v, want nil", err)
+	}
+}
+
+func TestEnforceDecisionCardinalityRejectsUnknownDecisionIndex(t *testing.T) {
+	err := EnforceDecisionCardinality(
+		[]artifacts.Candidate{{Index: 1}},
+		[]contracts.ValidationDecision{Approved(2)},
+	)
+
+	assertCardinalityError(t, err, "unknown candidate index 2")
+}
+
+func TestEnforceDecisionCardinalityRejectsDuplicateDecisionIndex(t *testing.T) {
+	err := EnforceDecisionCardinality(
+		[]artifacts.Candidate{{Index: 1}, {Index: 2}},
+		[]contracts.ValidationDecision{Approved(1), Approved(1)},
+	)
+
+	assertCardinalityError(t, err, "duplicate decision")
+}
+
+func TestEnforceDecisionCardinalityRejectsMissingDecisionIndex(t *testing.T) {
+	err := EnforceDecisionCardinality(
+		[]artifacts.Candidate{{Index: 1}, {Index: 2}},
+		[]contracts.ValidationDecision{Approved(1)},
+	)
+
+	assertCardinalityError(t, err, "1 decisions for 2 candidates")
+}
+
+func TestEnforceDecisionCardinalityRejectsDuplicateCandidateIndex(t *testing.T) {
+	err := EnforceDecisionCardinality(
+		[]artifacts.Candidate{{Index: 1}, {Index: 1}},
+		[]contracts.ValidationDecision{Approved(1), Approved(1)},
+	)
+
+	assertCardinalityError(t, err, "candidate index 1 is duplicated")
+}
+
+func assertCardinalityError(t *testing.T, err error, want string) {
+	t.Helper()
+
+	if err == nil {
+		t.Fatal("EnforceDecisionCardinality() error = nil, want error")
+	}
+	if !strings.Contains(err.Error(), want) {
+		t.Fatalf("EnforceDecisionCardinality() error = %q, want substring %q", err.Error(), want)
+	}
+}