feat(policy): the npm-family rule admits allowed, and only strengthens

.gds/bundle.lock.yaml

@@ -5,14 +5,14 @@ bundle:
   version: "0.4.0-dev"
   release_sequence: 0
   channel: "development"
-  source_tree_digest: "sha256:66532e92cee2ba8351911491ea4d8267fe853db10ebe36559551cb21aad5f209"
-  digest: "sha256:02032875c4b1e479d953ba4e9b766cf260bc469a81c38856ab6a6c6044b1c147"
+  source_tree_digest: "sha256:c7c04a600276303a2b4b63ccd2211fcb59eb94bfdcc6320e02eded9c0d2c2b10"
+  digest: "sha256:e753bacfdd5eedd658dbb63a82f9ce84a3b7efb2b14ae1fd55550fe040a003f5"
 
 projection:
-  input_digest: "sha256:02a7ff040caee7de0f5de1b2402485a7e6972b68e867413ad7a1d71add5d0336"
-  output_digest: "sha256:8fd7fc9e1adc79eec4876daaa1d9711882d3959584c92fc5c427c64ee6ecebce"
+  input_digest: "sha256:ba8b4e3da061c68235be603206bcb1042ec9091b4477da9bfbe302273042b4bb"
+  output_digest: "sha256:8efad1c40b82dda2d01a4ca37756b38bfae9f66cce4ac0f4808b2913d918278b"
   files:
     - path: ".gds/compiled-policy.json"
       digest: "sha256:78d09606bb4168d74bce1f50ab62b46a7ded34652c6b23af1badfd26dd060e94"
     - path: ".github/workflows/gds-ci.yml"
-      digest: "sha256:184bc5f09a65158b07fe4d6948c4d805869ddb35f9dcfaf528c5f5b4720abebb"
+      digest: "sha256:a2590f9aaec401c3e313fa639416e8a6b45ddfb96c3e3947a0b0b8c6a6e1dc57"

.github/workflows/gds-ci.yml

@@ -1,8 +1,8 @@
 # GENERATED FILE - DO NOT EDIT DIRECTLY
 # generator: gds
 # bundle: 0.4.0-dev
-# source-tree-digest: sha256:66532e92cee2ba8351911491ea4d8267fe853db10ebe36559551cb21aad5f209
-# input-digest: sha256:02a7ff040caee7de0f5de1b2402485a7e6972b68e867413ad7a1d71add5d0336
+# source-tree-digest: sha256:c7c04a600276303a2b4b63ccd2211fcb59eb94bfdcc6320e02eded9c0d2c2b10
+# input-digest: sha256:ba8b4e3da061c68235be603206bcb1042ec9091b4477da9bfbe302273042b4bb
 # output-digest: sha256:01fb4854784be9e4564bcc84e70786484b370879be5e5ab1dd49f8b73ea2dea4
 # edit-source:
 #   - .gds/repository.yaml

core/compiler/compiler.go

@@ -22,12 +22,16 @@ var policyTierOrder = map[string]int{
 }
 
 var monotonicStrength = map[string]map[string]int{
-	"security.external_write_requires_approval":     {"false": 0, "true": 1},
-	"security.public_projection_scan":               {"optional": 0, "required": 1},
-	"context.private_parent_persistence":            {"ephemeral-only": 0, "forbidden": 1},
-	"agent.generated_projection_edit":               {"warn": 0, "forbidden": 1},
-	"security.secrets_in_repository":                {"forbidden": 1},
-	"package_management.npm_family_on_managed_path": {"forbidden": 1},
+	"security.external_write_requires_approval": {"false": 0, "true": 1},
+	"security.public_projection_scan":           {"optional": 0, "required": 1},
+	"context.private_parent_persistence":        {"ephemeral-only": 0, "forbidden": 1},
+	"agent.generated_projection_edit":           {"warn": 0, "forbidden": 1},
+	"security.secrets_in_repository":            {"forbidden": 1},
+	// "allowed" joined the vocabulary when the estate-wide ban on the npm
+	// family collided with fixed decision 13 -- every toolchain a project
+	// actually uses must work. The base may allow; a role like control-plane
+	// may only strengthen to forbidden, never the reverse.
+	"package_management.npm_family_on_managed_path": {"allowed": 0, "forbidden": 1},
 	"package_management.mutable_version_resolution": {"forbidden": 1},
 	"package_management.remote_stream_to_shell":     {"forbidden": 1},
 }

core/compiler/compiler_test.go

@@ -425,3 +425,22 @@ func testRepositoryRoot(t *testing.T) string {
 	}
 	return filepath.Clean(filepath.Join(filepath.Dir(currentFile), "..", ".."))
 }
+
+// TestNpmFamilyStrengthensButNeverWeakens covers the vocabulary "allowed"
+// gained when the estate-wide npm-family ban collided with the owner's fixed
+// decision that every toolchain a project actually uses must work. A role may
+// strengthen the base's allowed to forbidden; the reverse is a weakening and
+// must be refused exactly like every other monotonic field.
+func TestNpmFamilyStrengthensButNeverWeakens(t *testing.T) {
+	t.Parallel()
+	path := "package_management.npm_family_on_managed_path"
+	if isWeakening(path, "allowed", "forbidden") {
+		t.Fatal("strengthening allowed -> forbidden was refused")
+	}
+	if !isWeakening(path, "forbidden", "allowed") {
+		t.Fatal("weakening forbidden -> allowed was permitted")
+	}
+	if !isWeakening(path, "allowed", "unheard-of") {
+		t.Fatal("an unknown value did not count as weakening")
+	}
+}

schemas/v1/policy.schema.json

@@ -422,7 +422,7 @@
           "uniqueItems": true,
           "items": { "type": "string" }
         },
-        "npm_family_on_managed_path": { "const": "forbidden" },
+        "npm_family_on_managed_path": { "enum": ["allowed", "forbidden"] },
         "mutable_version_resolution": { "const": "forbidden" },
         "remote_stream_to_shell": { "const": "forbidden" }
       }