fixup! WIP

README.md

@@ -493,6 +493,20 @@ export const redisPrimary = kubernetesAddress("redis-primary", {
     ],
   },
 });
+
+// constraints
+const const redisPrimary = kubernetesAddress("redis-primary", {
+  constraints: [
+    {
+      description: "must be allowed",
+      constrain: ({ host, port }) =>
+        [
+          "insecure.redis.example.org:80",
+          "secure.redis.example.org:443",
+        ].includes(`${host}:${port}`) || "not allowed",
+    },
+  ],
+});
 ```
 
 ### `networkPortNumber`

test/suite/declaration/kubernetes-address.spec.ts

@@ -587,6 +587,58 @@ describe("Kubernetes address declarations", () => {
     });
   });
 
+  describe("when the declaration has the constraints from the README", () => {
+    beforeEach(() => {
+      declaration = kubernetesAddress("redis-primary", {
+        constraints: [
+          {
+            description: "must be allowed",
+            constrain: ({ host, port }) =>
+              [
+                "insecure.redis.example.org:80",
+                "secure.redis.example.org:443",
+              ].includes(`${host}:${port}`) || "not allowed",
+          },
+        ],
+      });
+    });
+
+    describe("when the value satisfies the constraints", () => {
+      beforeEach(() => {
+        process.env.REDIS_PRIMARY_SERVICE_HOST = "secure.redis.example.org";
+        process.env.REDIS_PRIMARY_SERVICE_PORT = "443";
+
+        initialize({ onInvalid: noop });
+      });
+
+      describe(".value()", () => {
+        it("returns the value", () => {
+          expect(declaration.value()).toEqual({
+            host: "secure.redis.example.org",
+            port: 443,
+          });
+        });
+      });
+    });
+
+    describe("when the value violates the constraints", () => {
+      beforeEach(() => {
+        process.env.REDIS_PRIMARY_SERVICE_HOST = "secure.redis.example.org";
+        process.env.REDIS_PRIMARY_SERVICE_PORT = "80";
+
+        initialize({ onInvalid: noop });
+      });
+
+      describe(".value()", () => {
+        it("throws", () => {
+          expect(() => {
+            declaration.value();
+          }).toThrow("not allowed");
+        });
+      });
+    });
+  });
+
   describe.each`
     description               | host
     ${"IPv4"}                 | ${"192.168.1.2"}