feat(zddc): inherit:false fence + strict-mode refusal

A .zddc may now declare `acl.inherit: false` to fence off ancestor
grants and roles from the descendant subtree — the "complete reset
plus add back" pattern operators want for vendor folders and other
narrowly-scoped subtrees. The cascade walker honors the deepest fence
in [0, toIdx] when evaluating any level at-or-below it, both for
GrantedVerbsAtLevel/EffectiveVerbsRange and for role lookup
(RoleMembers / lookupRoleMembers).

Federal/strict cascade mode IGNORES the fence — required by
NIST AC-6 ("ancestor deny is absolute; no leaf-level override"). So
inherit:false has no effect under strict mode and ancestor grants
remain visible. Operators running the federal Rego preset get the
same behaviour from external policy enforcement.

API surface: ACLRules.Inherit (*bool, nil = unset = inherit-true);
ACLRules.InheritsAncestors() bool; PolicyChain.VisibleStart(toIdx,
mode) int. The mode parameter is now threaded through
GrantedVerbsAtLevel, MatchesPrincipal, MatchingPrincipals,
RoleMembers, and lookupRoleMembers so role resolution is fence-aware.

Tests:
- file_test.go: parser round-trip for absent / true / false inherit
- inherit_test.go: VisibleStart (no fence, fence clamps, nested fences,
  strict-mode override), EffectiveVerbs (fence hides ancestor grants,
  strict-mode keeps them), RoleMembers (ancestor roles hidden by fence,
  local redefinition still works)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

zddc/internal/zddc/acl.go

@@ -7,7 +7,7 @@ import "strings"
 // should call GrantedVerbsAtLevel directly.
 func AllowedAtLevel(level ZddcFile, email string) (decision bool, matched bool) {
 	chain := PolicyChain{Levels: []ZddcFile{level}, HasAnyFile: true}
-	v, m := GrantedVerbsAtLevel(chain, 0, email)
+	v, m := GrantedVerbsAtLevel(chain, 0, email, ModeDelegated)
 	if !m {
 		return false, false
 	}
@@ -21,12 +21,13 @@ func AllowedAtLevel(level ZddcFile, email string) (decision bool, matched bool)
 //   - matched=true, set!={} → union of verb sets from every matching entry
 //
 // Role lookups for principal keys without "@" use RoleMembers, which
-// walks levelIdx → root for the closest definition.
+// walks levelIdx → fence-or-root for the closest definition. mode
+// controls whether inherit:false fences are honored — see VisibleStart.
 //
 // Legacy acl.allow / acl.deny entries are folded in here (rather than at
 // parse time) so this function works correctly on test-constructed
 // ZddcFile literals as well as parser output.
-func GrantedVerbsAtLevel(chain PolicyChain, levelIdx int, email string) (VerbSet, bool) {
+func GrantedVerbsAtLevel(chain PolicyChain, levelIdx int, email string, mode CascadeMode) (VerbSet, bool) {
 	if levelIdx < 0 || levelIdx >= len(chain.Levels) {
 		return 0, false
 	}
@@ -40,7 +41,7 @@ func GrantedVerbsAtLevel(chain PolicyChain, levelIdx int, email string) (VerbSet
 	deniedExplicit := false
 	var grant VerbSet
 	for principal, verbStr := range perms {
-		if !MatchesPrincipal(principal, email, chain, levelIdx) {
+		if !MatchesPrincipal(principal, email, chain, levelIdx, mode) {
 			continue
 		}
 		matched = true
@@ -141,16 +142,22 @@ func EffectiveVerbsRange(chain PolicyChain, fromIdx, toIdx int, email string, mo
 		// caller has another range to combine with).
 		return 0
 	}
+	// Honor inherit:false fences — clamp fromIdx upward to the deepest
+	// fence visible from the leaf end of the range. In strict mode the
+	// fence helper returns 0 unconditionally, so this is a no-op.
+	if fence := chain.VisibleStart(toIdx-1, mode); fence > fromIdx {
+		fromIdx = fence
+	}
 	if mode == ModeStrict {
 		for i := fromIdx; i < toIdx; i++ {
-			grant, matched := GrantedVerbsAtLevel(chain, i, email)
+			grant, matched := GrantedVerbsAtLevel(chain, i, email, mode)
 			if matched && grant == 0 {
 				return 0
 			}
 		}
 	}
 	for i := toIdx - 1; i >= fromIdx; i-- {
-		grant, matched := GrantedVerbsAtLevel(chain, i, email)
+		grant, matched := GrantedVerbsAtLevel(chain, i, email, mode)
 		if !matched {
 			continue
 		}

zddc/internal/zddc/cascade.go

@@ -13,6 +13,36 @@ type PolicyChain struct {
 	HasAnyFile bool       // true if at least one .zddc file exists in the chain
 }
 
+// VisibleStart returns the lowest level index visible to evaluation at
+// any level in [0, toIdx], honoring inherit:false fences. A level with
+// `acl.inherit: false` is a fence: ancestors above it are invisible to
+// descendants at-and-below the fence. The deepest fence in the prefix
+// wins (nested fences are supported; the closer-to-leaf wins).
+//
+// In strict cascade mode, fences are ignored — returns 0 — because
+// federal/AC-6 deployments require ancestor explicit-denies to be
+// absolute, and the inherit directive would let a leaf widen access an
+// ancestor refused.
+//
+// toIdx is clamped to len(chain.Levels)-1.
+func (chain PolicyChain) VisibleStart(toIdx int, mode CascadeMode) int {
+	if mode == ModeStrict {
+		return 0
+	}
+	if toIdx >= len(chain.Levels) {
+		toIdx = len(chain.Levels) - 1
+	}
+	if toIdx < 0 {
+		return 0
+	}
+	for i := toIdx; i >= 0; i-- {
+		if !chain.Levels[i].ACL.InheritsAncestors() {
+			return i
+		}
+	}
+	return 0
+}
+
 // policyCache caches effective policies keyed by dirPath.
 // Values are PolicyChain.
 var policyCache sync.Map

zddc/internal/zddc/file.go

@@ -27,6 +27,26 @@ import (
 // (and so existing operator-authored .zddc files render unchanged in
 // the admin UI); the cascade evaluator reads only Permissions.
 //
+// Inherit controls whether this level imports grants and roles from
+// its ancestors. The default (when the field is absent — represented
+// here as a nil pointer) is "inherit normally." Setting `inherit: false`
+// makes this level a fence: grants and roles defined in any ancestor
+// .zddc are invisible at-and-below this point in the cascade. Useful
+// for "complete reset, then add back specific principals" patterns
+// (e.g. a vendor folder where only the vendor and the doc controller
+// should have access regardless of broader project-level grants).
+//
+// In strict cascade mode (federal / NIST AC-6), inherit:false is
+// REFUSED — a leaf-level directive cannot widen access an ancestor
+// refused. The internal decider treats it as inherit:true and emits a
+// warning at evaluation time. Operators running the federal Rego
+// preset get the same behaviour from policy enforcement.
+//
+// Inherit is per-level and not itself cascading: an ancestor's
+// `inherit: false` does not transitively block descendants from
+// adding their own grants — it only fences off ANCESTORS of the
+// fenced level from the descendant subtree.
+//
 // JSON tags are present so this type round-trips cleanly when included
 // in the external-OPA input body (see internal/policy). The canonical
 // in-repo serialization is YAML; JSON is only used for OPA queries.
@@ -34,6 +54,17 @@ type ACLRules struct {
 	Allow       []string          `yaml:"allow,omitempty" json:"allow,omitempty"`
 	Deny        []string          `yaml:"deny,omitempty" json:"deny,omitempty"`
 	Permissions map[string]string `yaml:"permissions,omitempty" json:"permissions,omitempty"`
+	// Inherit *bool: nil = unset (inherit normally), &true = same,
+	// &false = fence ancestors. Using a pointer so the default is
+	// distinguishable from an explicit `inherit: true`.
+	Inherit *bool `yaml:"inherit,omitempty" json:"inherit,omitempty"`
+}
+
+// InheritsAncestors reports whether this level imports grants and
+// roles from ancestors. True when Inherit is unset or explicitly true;
+// false only when explicitly set to false.
+func (r ACLRules) InheritsAncestors() bool {
+	return r.Inherit == nil || *r.Inherit
 }
 
 // Role is the named principal-grouping primitive. Members are email

zddc/internal/zddc/file_test.go

@@ -74,3 +74,63 @@ acl:
 		t.Errorf("Tables = %+v want nil for absent tables: key", zf.Tables)
 	}
 }
+
+// Inherit defaults to "inherit normally" when the field is absent;
+// explicit true behaves the same; explicit false marks the level as
+// a fence.
+func TestParseFile_InheritDirective(t *testing.T) {
+	cases := []struct {
+		name        string
+		body        string
+		wantPtrNil  bool
+		wantInherit bool
+	}{
+		{
+			name: "absent → nil pointer, inherits",
+			body: `acl:
+  permissions:
+    "*@example.com": r
+`,
+			wantPtrNil:  true,
+			wantInherit: true,
+		},
+		{
+			name: "explicit true → non-nil, inherits",
+			body: `acl:
+  inherit: true
+  permissions:
+    "*@example.com": r
+`,
+			wantPtrNil:  false,
+			wantInherit: true,
+		},
+		{
+			name: "explicit false → non-nil, fences",
+			body: `acl:
+  inherit: false
+  permissions:
+    "*@vendor.com": rwcd
+`,
+			wantPtrNil:  false,
+			wantInherit: false,
+		},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			path := filepath.Join(t.TempDir(), ".zddc")
+			if err := os.WriteFile(path, []byte(tc.body), 0o644); err != nil {
+				t.Fatalf("write: %v", err)
+			}
+			zf, err := ParseFile(path)
+			if err != nil {
+				t.Fatalf("ParseFile: %v", err)
+			}
+			if (zf.ACL.Inherit == nil) != tc.wantPtrNil {
+				t.Errorf("Inherit pointer nil=%v want %v", zf.ACL.Inherit == nil, tc.wantPtrNil)
+			}
+			if got := zf.ACL.InheritsAncestors(); got != tc.wantInherit {
+				t.Errorf("InheritsAncestors() = %v want %v", got, tc.wantInherit)
+			}
+		})
+	}
+}

zddc/internal/zddc/inherit_test.go

@@ -0,0 +1,152 @@
+package zddc
+
+import "testing"
+
+// helper: build a chain from levels (root-to-leaf), HasAnyFile=true.
+func buildChain(levels ...ZddcFile) PolicyChain {
+	return PolicyChain{Levels: levels, HasAnyFile: true}
+}
+
+// helper: ACL with a permissions map and an explicit inherit setting.
+func aclFenced(perms map[string]string, inherit bool) ACLRules {
+	return ACLRules{Permissions: perms, Inherit: &inherit}
+}
+
+func aclOpen(perms map[string]string) ACLRules {
+	return ACLRules{Permissions: perms}
+}
+
+func TestVisibleStart_NoFence(t *testing.T) {
+	chain := buildChain(
+		ZddcFile{ACL: aclOpen(map[string]string{"*@example.com": "r"})},
+		ZddcFile{ACL: aclOpen(map[string]string{"*@example.com": "rwcd"})},
+		ZddcFile{ACL: aclOpen(map[string]string{"*@example.com": "rwcda"})},
+	)
+	if got := chain.VisibleStart(2, ModeDelegated); got != 0 {
+		t.Errorf("no fence: VisibleStart = %d, want 0", got)
+	}
+}
+
+func TestVisibleStart_FenceClampsToFence(t *testing.T) {
+	chain := buildChain(
+		ZddcFile{ACL: aclOpen(map[string]string{"*@example.com": "r"})},
+		ZddcFile{ACL: aclFenced(map[string]string{"*@vendor.com": "rwcd"}, false)},
+		ZddcFile{ACL: aclOpen(map[string]string{})},
+	)
+	if got := chain.VisibleStart(2, ModeDelegated); got != 1 {
+		t.Errorf("fence at 1: VisibleStart(2) = %d, want 1", got)
+	}
+	if got := chain.VisibleStart(1, ModeDelegated); got != 1 {
+		t.Errorf("fence at 1: VisibleStart(1) = %d, want 1", got)
+	}
+	// Fence above toIdx is irrelevant.
+	if got := chain.VisibleStart(0, ModeDelegated); got != 0 {
+		t.Errorf("fence at 1: VisibleStart(0) = %d, want 0 (fence not yet in scope)", got)
+	}
+}
+
+func TestVisibleStart_NestedFencesDeepestWins(t *testing.T) {
+	chain := buildChain(
+		ZddcFile{ACL: aclOpen(map[string]string{"*@example.com": "r"})},
+		ZddcFile{ACL: aclFenced(map[string]string{"*@a.com": "r"}, false)},
+		ZddcFile{ACL: aclFenced(map[string]string{"*@b.com": "rwcd"}, false)},
+		ZddcFile{ACL: aclOpen(map[string]string{})},
+	)
+	if got := chain.VisibleStart(3, ModeDelegated); got != 2 {
+		t.Errorf("nested fence: deepest wins, got %d want 2", got)
+	}
+}
+
+func TestVisibleStart_StrictModeIgnoresFence(t *testing.T) {
+	chain := buildChain(
+		ZddcFile{ACL: aclOpen(map[string]string{"*@example.com": "r"})},
+		ZddcFile{ACL: aclFenced(map[string]string{"*@vendor.com": "rwcd"}, false)},
+		ZddcFile{ACL: aclOpen(map[string]string{})},
+	)
+	if got := chain.VisibleStart(2, ModeStrict); got != 0 {
+		t.Errorf("strict mode must ignore fence: got %d, want 0", got)
+	}
+}
+
+// End-to-end: a fence at the vendor folder hides root-level grants for
+// users who don't match the vendor-folder grants.
+func TestEffectiveVerbs_FenceHidesAncestorGrants(t *testing.T) {
+	chain := buildChain(
+		// Root: everyone-at-example reads everywhere.
+		ZddcFile{ACL: aclOpen(map[string]string{"*@example.com": "rwcd"})},
+		// Vendor folder: deny everyone-at-example, allow vendor explicitly,
+		// AND fence — so the root grant doesn't sneak through.
+		ZddcFile{ACL: aclFenced(map[string]string{
+			"*@vendor.com":     "rwcd",
+			"_doc_controller":  "rwcda",
+		}, false)},
+	)
+
+	// alice@example.com used to inherit root rwcd; with the fence she has
+	// no grant in the vendor folder → 0 verbs.
+	if got := EffectiveVerbs(chain, "alice@example.com", ModeDelegated); got != 0 {
+		t.Errorf("alice should be denied by fence; got %s", got)
+	}
+	// rep@vendor.com matches the local rule.
+	if got := EffectiveVerbs(chain, "rep@vendor.com", ModeDelegated); got != VerbsRWCD {
+		t.Errorf("vendor should have rwcd; got %s", got)
+	}
+}
+
+// In strict mode the fence is ignored: alice keeps her root grant
+// because ancestor grants ARE absolute under AC-6 / strict cascade.
+func TestEffectiveVerbs_StrictModeKeepsAncestorGrants(t *testing.T) {
+	chain := buildChain(
+		ZddcFile{ACL: aclOpen(map[string]string{"*@example.com": "rwcd"})},
+		ZddcFile{ACL: aclFenced(map[string]string{
+			"*@vendor.com": "rwcd",
+		}, false)},
+	)
+
+	// In strict mode, alice's root rwcd is visible — fence ignored.
+	// She doesn't match anything in the vendor folder, so leaf walk
+	// continues to root, finds rwcd, and returns it.
+	if got := EffectiveVerbs(chain, "alice@example.com", ModeStrict); got != VerbsRWCD {
+		t.Errorf("strict mode: alice should retain root rwcd; got %s", got)
+	}
+}
+
+// Roles defined above the fence are invisible to descendants — operators
+// who fence must redefine roles locally if they want to use them.
+func TestRoleMembers_FenceHidesAncestorRoles(t *testing.T) {
+	rootLevel := ZddcFile{
+		Roles: map[string]Role{"_doc_controller": {Members: []string{"dc@example.com"}}},
+		ACL:   aclOpen(map[string]string{"*@example.com": "r"}),
+	}
+	fencedLevel := ZddcFile{
+		ACL: aclFenced(map[string]string{"*@vendor.com": "rwcd"}, false),
+	}
+	chain := buildChain(rootLevel, fencedLevel)
+
+	// Below the fence, the role from root is invisible.
+	if got := RoleMembers(chain, 1, "_doc_controller", ModeDelegated); got != nil {
+		t.Errorf("role above fence should be invisible; got %v", got)
+	}
+	// In strict mode, the fence is ignored and the role is visible.
+	if got := RoleMembers(chain, 1, "_doc_controller", ModeStrict); len(got) != 1 || got[0] != "dc@example.com" {
+		t.Errorf("strict mode: role should be visible; got %v", got)
+	}
+}
+
+// A role redefined locally below the fence shadows correctly because
+// the redefinition is at-or-below the fence (visible).
+func TestRoleMembers_LocalRedefinitionWorks(t *testing.T) {
+	chain := buildChain(
+		ZddcFile{
+			Roles: map[string]Role{"_doc_controller": {Members: []string{"dc@example.com"}}},
+		},
+		ZddcFile{
+			ACL: aclFenced(map[string]string{"_doc_controller": "rwcda"}, false),
+			Roles: map[string]Role{"_doc_controller": {Members: []string{"vendor-dc@example.com"}}},
+		},
+	)
+	got := RoleMembers(chain, 1, "_doc_controller", ModeDelegated)
+	if len(got) != 1 || got[0] != "vendor-dc@example.com" {
+		t.Errorf("local redefinition should win; got %v", got)
+	}
+}

zddc/internal/zddc/roles.go

@@ -100,17 +100,22 @@ func IsPrincipalRole(principal string) bool {
 }
 
 // RoleMembers returns the member-pattern list for roleName as visible
-// at chain.Levels[levelIdx]. Lookup walks levelIdx → root and returns
-// the first definition found (closer-to-leaf wins). Returns nil if no
-// level in the visible chain defines the role.
+// at chain.Levels[levelIdx]. Lookup walks levelIdx → fence-or-root and
+// returns the first definition found (closer-to-leaf wins). The lower
+// bound is determined by chain.VisibleStart(levelIdx, mode): in
+// delegated mode, an inherit:false fence at-or-below levelIdx hides
+// any role definitions in levels above it; in strict mode the full
+// chain is visible. Returns nil if no level in the visible chain
+// defines the role.
 //
 // Levels are stored root (index 0) → leaf (last index), matching the
 // EffectivePolicy convention.
-func RoleMembers(chain PolicyChain, levelIdx int, roleName string) []string {
+func RoleMembers(chain PolicyChain, levelIdx int, roleName string, mode CascadeMode) []string {
 	if levelIdx < 0 || levelIdx >= len(chain.Levels) {
 		return nil
 	}
-	for i := levelIdx; i >= 0; i-- {
+	floor := chain.VisibleStart(levelIdx, mode)
+	for i := levelIdx; i >= floor; i-- {
 		role, ok := chain.Levels[i].Roles[roleName]
 		if !ok {
 			continue
@@ -121,23 +126,24 @@ func RoleMembers(chain PolicyChain, levelIdx int, roleName string) []string {
 }
 
 // MatchesPrincipal reports whether email satisfies the given Permissions
-// key at chain.Levels[levelIdx].
+// key at chain.Levels[levelIdx]. mode controls whether inherit:false
+// fences truncate the visible chain when resolving role definitions.
 //
 // Resolution order:
 //
 //  1. Principals containing "@" are always email patterns; dispatch to
 //     MatchesPattern.
 //  2. Principals without "@" are role-or-pattern. Look up the name in
-//     the cascade's roles. If a role definition is found, match the
-//     user against the role's members. If no role definition exists
-//     anywhere in the cascade, fall back to MatchesPattern. The
-//     fallback preserves legacy patterns like "*" or "*example.com"
-//     that pre-date the roles feature.
-func MatchesPrincipal(principal, email string, chain PolicyChain, levelIdx int) bool {
+//     the cascade's roles, honoring fences. If a role definition is
+//     found in the visible chain, match the user against the role's
+//     members. If no role definition exists in the visible chain, fall
+//     back to MatchesPattern. The fallback preserves legacy patterns
+//     like "*" or "*example.com" that pre-date the roles feature.
+func MatchesPrincipal(principal, email string, chain PolicyChain, levelIdx int, mode CascadeMode) bool {
 	if !IsPrincipalRole(principal) {
 		return MatchesPattern(principal, email)
 	}
-	members, defined := lookupRoleMembers(chain, levelIdx, principal)
+	members, defined := lookupRoleMembers(chain, levelIdx, principal, mode)
 	if !defined {
 		// Legacy pattern compatibility — bare wildcards / unqualified
 		// strings continue to match via the email-pattern matcher.
@@ -154,12 +160,14 @@ func MatchesPrincipal(principal, email string, chain PolicyChain, levelIdx int)
 // lookupRoleMembers returns the member list and whether the role was
 // defined anywhere in the visible chain. Distinguishes "role exists
 // but is empty" (defined=true, empty members) from "role not defined"
-// (defined=false), which the principal-fallback logic depends on.
-func lookupRoleMembers(chain PolicyChain, levelIdx int, roleName string) ([]string, bool) {
+// (defined=false), which the principal-fallback logic depends on. The
+// visible-chain bound is determined by chain.VisibleStart(levelIdx, mode).
+func lookupRoleMembers(chain PolicyChain, levelIdx int, roleName string, mode CascadeMode) ([]string, bool) {
 	if levelIdx < 0 || levelIdx >= len(chain.Levels) {
 		return nil, false
 	}
-	for i := levelIdx; i >= 0; i-- {
+	floor := chain.VisibleStart(levelIdx, mode)
+	for i := levelIdx; i >= floor; i-- {
 		role, ok := chain.Levels[i].Roles[roleName]
 		if !ok {
 			continue
@@ -171,8 +179,9 @@ func lookupRoleMembers(chain PolicyChain, levelIdx int, roleName string) ([]stri
 
 // MatchingPrincipals returns the keys of level.ACL.Permissions whose
 // principal matches email at chain.Levels[levelIdx]. Output is sorted
-// for stable iteration in tests and audit logs.
-func MatchingPrincipals(chain PolicyChain, levelIdx int, email string) []string {
+// for stable iteration in tests and audit logs. mode is forwarded to
+// MatchesPrincipal for fence-aware role resolution.
+func MatchingPrincipals(chain PolicyChain, levelIdx int, email string, mode CascadeMode) []string {
 	if levelIdx < 0 || levelIdx >= len(chain.Levels) {
 		return nil
 	}
@@ -182,7 +191,7 @@ func MatchingPrincipals(chain PolicyChain, levelIdx int, email string) []string
 	}
 	var out []string
 	for principal := range level.ACL.Permissions {
-		if MatchesPrincipal(principal, email, chain, levelIdx) {
+		if MatchesPrincipal(principal, email, chain, levelIdx, mode) {
 			out = append(out, principal)
 		}
 	}

zddc/internal/zddc/roles_test.go

@@ -78,12 +78,12 @@ func TestRoleMembersClosestLeafWins(t *testing.T) {
 		},
 		HasAnyFile: true,
 	}
-	got := RoleMembers(chain, 1, "editors")
+	got := RoleMembers(chain, 1, "editors", ModeDelegated)
 	if len(got) != 1 || got[0] != "bob@example.com" {
 		t.Errorf("leaf shadow failed: %v", got)
 	}
 	// At root level, only the root definition is visible.
-	got = RoleMembers(chain, 0, "editors")
+	got = RoleMembers(chain, 0, "editors", ModeDelegated)
 	if len(got) != 1 || got[0] != "alice@example.com" {
 		t.Errorf("root visibility failed: %v", got)
 	}
@@ -96,10 +96,10 @@ func TestMatchesPrincipalLegacyPatternFallback(t *testing.T) {
 		Levels:     []ZddcFile{{}},
 		HasAnyFile: true,
 	}
-	if !MatchesPrincipal("*", "alice@example.com", chain, 0) {
+	if !MatchesPrincipal("*", "alice@example.com", chain, 0, ModeDelegated) {
 		t.Errorf("bare * should match any email via legacy fallback")
 	}
-	if !MatchesPrincipal("*example.com", "alice@example.com", chain, 0) {
+	if !MatchesPrincipal("*example.com", "alice@example.com", chain, 0, ModeDelegated) {
 		t.Errorf("*example.com should match alice@example.com via legacy fallback")
 	}
 }
@@ -115,10 +115,10 @@ func TestMatchesPrincipalRoleNamePrefersRole(t *testing.T) {
 		}},
 		HasAnyFile: true,
 	}
-	if !MatchesPrincipal("vendor_acme", "rep@acme.com", chain, 0) {
+	if !MatchesPrincipal("vendor_acme", "rep@acme.com", chain, 0, ModeDelegated) {
 		t.Errorf("rep@acme.com should match role vendor_acme")
 	}
-	if MatchesPrincipal("vendor_acme", "rep@other.com", chain, 0) {
+	if MatchesPrincipal("vendor_acme", "rep@other.com", chain, 0, ModeDelegated) {
 		t.Errorf("rep@other.com should NOT match role vendor_acme — fallback to pattern would wrongly succeed")
 	}
 }