Return undefined not null when resolving fails

[Etiquette] / model.test.js

diff --git a/model.test.js b/model.test.js
index 3e9982a7a4fb513495204b5d80608e4d04f2c6a9..ed1430e8a49246c1a97190eb3e64ca9e443bbad3 100644 (file)
--- a/model.test.js
+++ b/model.test.js
@@ -164,6 +164,12 @@ describe("TagSystem", () => {
       });
     });
 
+    describe(".constructor", () => {
+      it("[[Get]] is `Function`", () => {
+        assertStrictEquals(Tag.constructor, Function);
+      });
+    });
+
     describe(".fromIRI", () => {
       it("[[Call]] returns the persisted tag with the given I·R·I", () => {
         const tag = new Tag();
@@ -177,12 +183,12 @@ describe("TagSystem", () => {
         assertStrictEquals(retrieved.identifier, identifier);
       });
 
-      it("[[Call]] returns null if no tag with the given I·R·I has been persisted", () => {
+      it("[[Call]] returns undefined if no tag with the given I·R·I has been persisted", () => {
         assertStrictEquals(
           Tag.fromIRI(
             `https://${system.authorityName}/tag:${system.taggingEntity}:000-0000`,
           ),
-          null,
+          undefined,
         );
       });
 
@@ -206,8 +212,8 @@ describe("TagSystem", () => {
         assertStrictEquals(retrieved.identifier, identifier);
       });
 
-      it("[[Call]] returns null if no tag with the given identifier has been persisted", () => {
-        assertStrictEquals(Tag.fromIdentifier("000-0000"), null);
+      it("[[Call]] returns undefined if no tag with the given identifier has been persisted", () => {
+        assertStrictEquals(Tag.fromIdentifier("000-0000"), undefined);
       });
 
       it("[[Call]] throws if passed an invalid identifier", () => {
@@ -233,14 +239,14 @@ describe("TagSystem", () => {
         assertStrictEquals(retrieved.identifier, identifier);
       });
 
-      it("[[Call]] returns null if no tag with the given Tag U·R·I has been persisted", () => {
+      it("[[Call]] returns undefined if no tag with the given Tag U·R·I has been persisted", () => {
         assertStrictEquals(
           Tag.fromTagURI(`tag:${system.taggingEntity}:`),
-          null,
+          undefined,
         );
         assertStrictEquals(
           Tag.fromTagURI(`tag:${system.taggingEntity}:000-0000`),
-          null,
+          undefined,
         );
       });
 
@@ -256,12 +262,6 @@ describe("TagSystem", () => {
       });
     });
 
-    describe(".getSystem", () => {
-      it("[[Has]] is not present", () => {
-        assertFalse("getSystem" in Tag);
-      });
-    });
-
     describe(".identifiers", () => {
       it("[[Call]] yields all the persisted identifiers", () => {
         const tags = new Set(function* () {
@@ -411,8 +411,10 @@ describe("TagSystem", () => {
       });
 
       it("[[Call]] throws when this is not a tag which can be placed in canon", () => {
+        const canon = new Tag("CanonTag");
+        canon.persist();
         assertThrows(() => {
-          new Tag().addInCanonTag();
+          new Tag().addInCanonTag(canon);
         });
       });
 
@@ -469,8 +471,10 @@ describe("TagSystem", () => {
       });
 
       it("[[Call]] throws when this is not a conceptual tag", () => {
+        const involved = new Tag();
+        involved.persist();
         assertThrows(() => {
-          new Tag().addInvolvesTag();
+          new Tag().addInvolvesTag(involved);
         });
       });