Lady’s Gitweb - Etiquette/blob - model.test.js

   1 // 📧🏷️ Étiquette ∷ model.test.js
   2 // ====================================================================
   3 //
   4 // Copyright © 2023 Lady [@ Lady’s Computer].
   5 //
   6 // This Source Code Form is subject to the terms of the Mozilla Public
   7 // License, v. 2.0. If a copy of the MPL was not distributed with this
   8 // file, You can obtain one at <https://mozilla.org/MPL/2.0/>.
   9
  10 import {
  11   assert,
  12   assertArrayIncludes,
  13   assertEquals,
  14   assertFalse,
  15   assertObjectMatch,
  16   assertStrictEquals,
  17   assertThrows,
  18   beforeEach,
  19   describe,
  20   it,
  21 } from "./dev-deps.js";
  22 import { TagSystem } from "./model.js";
  23
  24 describe("TagSystem", () => {
  25   it("[[Call]] throws", () => {
  26     assertThrows(() => {
  27       TagSystem();
  28     });
  29   });
  30
  31   it("[[Construct]] creates a new TagSystem", () => {
  32     assertStrictEquals(
  33       Object.getPrototypeOf(new TagSystem("example", "1972-12-31")),
  34       TagSystem.prototype,
  35     );
  36   });
  37
  38   it("[[Construct]] uses the identifier if provided", () => {
  39     assertStrictEquals(
  40       new TagSystem("example", "1972-12-31", "etaoin").identifier,
  41       "etaoin",
  42     );
  43   });
  44
  45   it("[[Construct]] uses an empty identifier if none is provided", () => {
  46     assertStrictEquals(
  47       new TagSystem("example", "1972-12-31").identifier,
  48       "",
  49     );
  50   });
  51
  52   it("[[Construct]] throws if provided an invalid domain", () => {
  53     assertThrows(() => {
  54       new TagSystem("example@example", "1972-12-31");
  55     });
  56     assertThrows(() => {
  57       new TagSystem("0.0.0.0", "1972-12-31");
  58     });
  59   });
  60
  61   it("[[Construct]] throws if provided an invalid date", () => {
  62     assertThrows(() => {
  63       new TagSystem("example", "1969");
  64     });
  65     assertThrows(() => {
  66       new TagSystem("example", "1972-12-31T00:00:00Z");
  67     });
  68   });
  69
  70   describe("::Tag", () => {
  71     let Tag;
  72     let system;
  73
  74     beforeEach(() => {
  75       system = new TagSystem("example", "1972-12-31");
  76       Tag = system.Tag;
  77     });
  78
  79     it("[[Get]] returns the same value every time", () => {
  80       assertStrictEquals(Tag, system.Tag);
  81     });
  82
  83     it("[[Call]] throws", () => {
  84       assertThrows(() => {
  85         Tag();
  86       });
  87     });
  88
  89     it("[[Construct]] returns a new Tag", () => {
  90       assertStrictEquals(
  91         Object.getPrototypeOf(new Tag()),
  92         Tag.prototype,
  93       );
  94     });
  95
  96     it('[[Construct]] defaults the kind to "Tag"', () => {
  97       assertStrictEquals(new Tag().kind, "Tag");
  98     });
  99
 100     it("[[Construct]] correctly sets the tag kind", () => {
 101       assertStrictEquals(
 102         new Tag("RelationshipTag").kind,
 103         "RelationshipTag",
 104       );
 105     });
 106
 107     it("[[Construct]] defaults the preferred label to the empty string", () => {
 108       assertStrictEquals(new Tag().prefLabel, "");
 109     });
 110
 111     it("[[Construct]] correctly sets the preferred label to a simple string", () => {
 112       assertStrictEquals(
 113         new Tag("RelationshipTag", "Shadow, Me").prefLabel,
 114         "Shadow, Me",
 115       );
 116     });
 117
 118     it("[[Construct]] initializes tag identifiers to null", () => {
 119       assertStrictEquals(
 120         new Tag().identifier,
 121         null,
 122       );
 123     });
 124
 125     it("[[Construct]] correctly sets the preferred label to a language‐tagged string", () => {
 126       assertEquals(
 127         {
 128           ...new Tag("RelationshipTag", {
 129             "@value": "Shadow, Me",
 130             "@language": "en",
 131           }).prefLabel,
 132         },
 133         { "@value": "Shadow, Me", "@language": "en" },
 134       );
 135     });
 136
 137     it("[[Construct]] throws if the tag kind is not recognized", () => {
 138       assertThrows(() => {
 139         new Tag("NotATag");
 140       });
 141     });
 142
 143     describe(".all", () => {
 144       it("[[Call]] yields all the persisted tags", () => {
 145         const tags = new Set(function* () {
 146           let i = 0;
 147           while (i++ < 5) {
 148             // Generate 5 tags and remember their identifiers.
 149             const tag = new Tag();
 150             tag.persist();
 151             yield tag.identifier;
 152           }
 153         }());
 154         for (const tag of Tag.all()) {
 155           assertStrictEquals(
 156             Object.getPrototypeOf(tag),
 157             Tag.prototype,
 158           );
 159         }
 160         assertEquals(
 161           new Set(Array.from(Tag.all(), (tag) => tag.identifier)),
 162           tags,
 163         );
 164       });
 165     });
 166
 167     describe(".fromIRI", () => {
 168       it("[[Call]] returns the persisted tag with the given I·R·I", () => {
 169         const tag = new Tag();
 170         tag.persist();
 171         const { identifier, iri } = tag;
 172         const retrieved = Tag.fromIRI(iri);
 173         assertStrictEquals(
 174           Object.getPrototypeOf(retrieved),
 175           Tag.prototype,
 176         );
 177         assertStrictEquals(retrieved.identifier, identifier);
 178       });
 179
 180       it("[[Call]] returns null if no tag with the given I·R·I has been persisted", () => {
 181         assertStrictEquals(
 182           Tag.fromIRI(
 183             `https://${system.authorityName}/tag:${system.taggingEntity}:000-0000`,
 184           ),
 185           null,
 186         );
 187       });
 188
 189       it("[[Call]] returns null if passed an invalid I·R·I", () => {
 190         assertStrictEquals(Tag.fromIRI(`bad iri`), null);
 191       });
 192     });
 193
 194     describe(".fromIdentifier", () => {
 195       it("[[Call]] returns the persisted tag with the given identifier", () => {
 196         const tag = new Tag();
 197         tag.persist();
 198         const { identifier } = tag;
 199         const retrieved = Tag.fromIdentifier(identifier);
 200         assertStrictEquals(
 201           Object.getPrototypeOf(retrieved),
 202           Tag.prototype,
 203         );
 204         assertStrictEquals(retrieved.identifier, identifier);
 205       });
 206
 207       it("[[Call]] returns null if no tag with the given identifier has been persisted", () => {
 208         assertStrictEquals(Tag.fromIdentifier("000-0000"), null);
 209       });
 210
 211       it("[[Call]] throws if passed an invalid identifier", () => {
 212         assertThrows(() => {
 213           Tag.fromIdentifier(""); // wrong format
 214         });
 215         assertThrows(() => {
 216           Tag.fromIdentifier("100-0000"); // bad checksum
 217         });
 218       });
 219     });
 220
 221     describe(".fromTagURI", () => {
 222       it("[[Call]] returns the persisted tag with the given Tag U·R·I", () => {
 223         const tag = new Tag();
 224         tag.persist();
 225         const { identifier, tagURI } = tag;
 226         const retrieved = Tag.fromTagURI(tagURI);
 227         assertStrictEquals(
 228           Object.getPrototypeOf(retrieved),
 229           Tag.prototype,
 230         );
 231         assertStrictEquals(retrieved.identifier, identifier);
 232       });
 233
 234       it("[[Call]] returns null if no tag with the given Tag U·R·I has been persisted", () => {
 235         assertStrictEquals(
 236           Tag.fromIRI(`tag:${system.taggingEntity}:`),
 237           null,
 238         );
 239         assertStrictEquals(
 240           Tag.fromIRI(`tag:${system.taggingEntity}:000-0000`),
 241           null,
 242         );
 243       });
 244
 245       it("[[Call]] throws if passed an invalid Tag U·R·I", () => {
 246         assertThrows(() => {
 247           Tag.fromTagURI(""); // wrong format
 248         });
 249         assertThrows(() => {
 250           Tag.fromTagURI(
 251             "tag:unexample,1970-01-01:Z", // incorrect tagging entity
 252           );
 253         });
 254       });
 255     });
 256
 257     describe(".getSystem", () => {
 258       it("[[Has]] is not present", () => {
 259         assertFalse("getSystem" in Tag);
 260       });
 261     });
 262
 263     describe(".identifiers", () => {
 264       it("[[Call]] yields all the persisted identifiers", () => {
 265         const tags = new Set(function* () {
 266           let i = 0;
 267           while (i++ < 5) {
 268             // Generate 5 tags and remember their identifiers.
 269             const tag = new Tag();
 270             tag.persist();
 271             yield tag.identifier;
 272           }
 273         }());
 274         assertEquals(
 275           new Set(Tag.identifiers()),
 276           tags,
 277         );
 278       });
 279     });
 280
 281     // `.[Storage.toInstance]` is tested by `.fromIdentifier`.
 282
 283     describe("::addAltLabel", () => {
 284       it("[[Call]] does nothing if called with no arguments", () => {
 285         const tag = new Tag();
 286         tag.addAltLabel();
 287         assertEquals([...tag.altLabels()], []);
 288       });
 289
 290       it("[[Call]] adds the provided alternative labels", () => {
 291         const tag = new Tag();
 292         tag.addAltLabel(
 293           "one",
 294           { "@value": "two" },
 295           { "@value": "three", "@language": "en" },
 296         );
 297         assertEquals(
 298           Array.from(
 299             tag.altLabels(),
 300             ($) => typeof $ == "string" ? $ : { ...$ },
 301           ),
 302           [
 303             "one",
 304             "two",
 305             { "@value": "three", "@language": "en" },
 306           ],
 307         );
 308       });
 309     });
 310
 311     describe("::addBroaderTag", () => {
 312       it("[[Call]] does nothing if called with no arguments", () => {
 313         const tag = new Tag();
 314         tag.addBroaderTag();
 315         assertEquals([...tag.broaderTags()], []);
 316       });
 317
 318       it("[[Call]] adds the provided broader tags", () => {
 319         const broader = new Tag();
 320         broader.persist();
 321         const broader2 = new Tag();
 322         broader2.persist();
 323         const tag = new Tag();
 324         tag.addBroaderTag(broader, broader2);
 325         assertEquals(
 326           Array.from(tag.broaderTags(), ($) => $.identifier),
 327           [broader.identifier, broader2.identifier],
 328         );
 329       });
 330
 331       it("[[Call]] throws when adding a non‐persisted tag", () => {
 332         const tag = new Tag();
 333         assertThrows(() => {
 334           tag.addBroaderTag(new Tag());
 335         });
 336       });
 337
 338       it("[[Call]] throws when adding an unrecognized identifier", () => {
 339         const tag = new Tag();
 340         assertThrows(() => {
 341           tag.addBroaderTag("000-0000"); // not persisted
 342         });
 343         assertThrows(() => {
 344           tag.addBroaderTag(""); // bad format
 345         });
 346       });
 347     });
 348
 349     describe("::addHiddenLabel", () => {
 350       it("[[Call]] does nothing if called with no arguments", () => {
 351         const tag = new Tag();
 352         tag.addHiddenLabel();
 353         assertEquals([...tag.hiddenLabels()], []);
 354       });
 355
 356       it("[[Call]] adds the provided hidden labels", () => {
 357         const tag = new Tag();
 358         tag.addHiddenLabel(
 359           "one",
 360           { "@value": "two" },
 361           { "@value": "three", "@language": "en" },
 362         );
 363         assertEquals(
 364           Array.from(
 365             tag.hiddenLabels(),
 366             ($) => typeof $ == "string" ? $ : { ...$ },
 367           ),
 368           [
 369             "one",
 370             "two",
 371             { "@value": "three", "@language": "en" },
 372           ],
 373         );
 374       });
 375     });
 376
 377     describe("::addInCanonTag", () => {
 378       it("[[Call]] does nothing if called with no arguments", () => {
 379         const tag = new Tag("EntityTag");
 380         tag.addInCanonTag();
 381         assertEquals([...tag.inCanonTags()], []);
 382       });
 383
 384       it("[[Call]] adds the provided canon tags", () => {
 385         const canon = new Tag("CanonTag");
 386         canon.persist();
 387         const canon2 = new Tag("CanonTag");
 388         canon2.persist();
 389         const tag = new Tag("EntityTag");
 390         tag.addInCanonTag(canon, canon2);
 391         assertEquals(
 392           Array.from(tag.inCanonTags(), ($) => $.identifier),
 393           [canon.identifier, canon2.identifier],
 394         );
 395       });
 396
 397       it("[[Call]] throws when this is not a tag which can be placed in canon", () => {
 398         assertThrows(() => {
 399           new Tag().addInCanonTag();
 400         });
 401       });
 402
 403       it("[[Call]] throws when provided with a non‐canon tag", () => {
 404         const notCanon = new Tag();
 405         notCanon.persist();
 406         const tag = new Tag("EntityTag");
 407         assertThrows(() => {
 408           tag.addInCanonTag(notCanon);
 409         });
 410       });
 411
 412       it("[[Call]] throws when adding a non‐persisted tag", () => {
 413         const tag = new Tag("EntityTag");
 414         assertThrows(() => {
 415           tag.addInCanonTag(new Tag("CanonTag"));
 416         });
 417       });
 418
 419       it("[[Call]] throws when adding an unrecognized identifier", () => {
 420         const tag = new Tag("EntityTag");
 421         assertThrows(() => {
 422           tag.addInCanonTag("000-0000"); // not persisted
 423         });
 424         assertThrows(() => {
 425           tag.addInCanonTag(""); // bad format
 426         });
 427       });
 428     });
 429
 430     describe("::addInvolvesTag", () => {
 431       it("[[Call]] does nothing if called with no arguments", () => {
 432         const tag = new Tag("ConceptualTag");
 433         tag.addInvolvesTag();
 434         assertEquals([...tag.involvesTags()], []);
 435       });
 436
 437       it("[[Call]] adds the provided tags", () => {
 438         const involved = new Tag();
 439         involved.persist();
 440         const involved2 = new Tag();
 441         involved2.persist();
 442         const tag = new Tag("ConceptualTag");
 443         tag.addInvolvesTag(involved, involved2);
 444         assertEquals(
 445           Array.from(tag.involvesTags(), ($) => $.identifier),
 446           [involved.identifier, involved2.identifier],
 447         );
 448       });
 449
 450       it("[[Call]] throws when this is not a conceptual tag", () => {
 451         assertThrows(() => {
 452           new Tag().addInvolvesTag();
 453         });
 454       });
 455
 456       it("[[Call]] throws when this is a relationship tag and provided with a non‐involvable tag", () => {
 457         const notInvolved = new Tag();
 458         notInvolved.persist();
 459         const tag = new Tag("RelationshipTag");
 460         assertThrows(() => {
 461           tag.addInvolvesTag(notInvolved);
 462         });
 463       });
 464
 465       it("[[Call]] throws when adding a non‐persisted tag", () => {
 466         const tag = new Tag("ConceptualTag");
 467         assertThrows(() => {
 468           tag.addInvolvesTag(new Tag());
 469         });
 470       });
 471
 472       it("[[Call]] throws when adding an unrecognized identifier", () => {
 473         const tag = new Tag("ConceptualTag");
 474         assertThrows(() => {
 475           tag.addInvolvesTag("000-0000"); // not persisted
 476         });
 477         assertThrows(() => {
 478           tag.addInvolvesTag(""); // bad format
 479         });
 480       });
 481     });
 482
 483     // `::altLabels` is tested by `::addAltLabel`.
 484
 485     describe("::authorityName", () => {
 486       it("[[Get]] returns the authority name of the tag system", () => {
 487         assertStrictEquals(
 488           new Tag().authorityName,
 489           system.authorityName,
 490         );
 491       });
 492     });
 493
 494     // `::broaderTags` is tested by `::addBroaderTag`.
 495
 496     describe("::broaderTransitiveTags", () => {
 497       it("[[Call]] returns broader tags transitively", () => {
 498         const superBroad = new Tag();
 499         superBroad.persist();
 500         const broad = new Tag();
 501         broad.addBroaderTag(superBroad);
 502         broad.persist();
 503         const tag = new Tag();
 504         tag.addBroaderTag(broad);
 505         assertEquals(
 506           Array.from(tag.broaderTransitiveTags(), ($) => $.identifier),
 507           [broad.identifier, superBroad.identifier],
 508         );
 509       });
 510
 511       it("[[Call]] cannot recurse infinitely", () => {
 512         const tag = new Tag();
 513         tag.persist();
 514         const broad = new Tag();
 515         broad.addBroaderTag(tag);
 516         broad.persist();
 517         tag.addBroaderTag(broad);
 518         tag.persist();
 519         assertEquals(
 520           Array.from(tag.broaderTransitiveTags(), ($) => $.identifier),
 521           [broad.identifier, tag.identifier],
 522         );
 523       });
 524     });
 525
 526     describe("::deleteAltLabel", () => {
 527       it("[[Call]] does nothing if called with no arguments", () => {
 528         const tag = new Tag();
 529         tag.addAltLabel("etaoin");
 530         tag.deleteAltLabel();
 531         assertEquals([...tag.altLabels()], ["etaoin"]);
 532       });
 533
 534       it("[[Call]] deletes only the provided hidden labels", () => {
 535         const tag = new Tag();
 536         tag.addAltLabel(
 537           "one",
 538           "two",
 539           { "@value": "three", "@language": "en" },
 540           "four",
 541         );
 542         tag.deleteAltLabel(
 543           "one",
 544           { "@value": "two" },
 545           { "@value": "three", "@language": "en" },
 546           { "@value": "four", "@language": "en" },
 547         );
 548         assertEquals([...tag.altLabels()], ["four"]);
 549       });
 550     });
 551
 552     describe("::deleteBroaderTag", () => {
 553       it("[[Call]] does nothing if called with no arguments", () => {
 554         const broader = new Tag();
 555         broader.persist();
 556         const tag = new Tag();
 557         tag.addBroaderTag(broader);
 558         tag.deleteBroaderTag();
 559         assertEquals(
 560           Array.from(tag.broaderTags(), ($) => $.identifier),
 561           [broader.identifier],
 562         );
 563       });
 564
 565       it("[[Call]] deletes only the provided broader tags", () => {
 566         const superBroader = new Tag();
 567         superBroader.persist();
 568         const broader = new Tag();
 569         broader.addBroaderTag(superBroader);
 570         broader.persist();
 571         const broader2 = new Tag();
 572         broader2.addBroaderTag(superBroader);
 573         broader2.persist();
 574         const tag = new Tag();
 575         tag.addBroaderTag(broader, broader2);
 576         tag.deleteBroaderTag(broader, superBroader, "000-0000", "");
 577         assertEquals(
 578           Array.from(tag.broaderTags(), ($) => $.identifier),
 579           [broader2.identifier],
 580         );
 581       });
 582     });
 583
 584     describe("::deleteHiddenLabel", () => {
 585       it("[[Call]] does nothing if called with no arguments", () => {
 586         const tag = new Tag();
 587         tag.addHiddenLabel("etaoin");
 588         tag.deleteHiddenLabel();
 589         assertEquals([...tag.hiddenLabels()], ["etaoin"]);
 590       });
 591
 592       it("[[Call]] deletes only the provided alternative labels", () => {
 593         const tag = new Tag();
 594         tag.addHiddenLabel(
 595           "one",
 596           "two",
 597           { "@value": "three", "@language": "en" },
 598           "four",
 599         );
 600         tag.deleteHiddenLabel(
 601           "one",
 602           { "@value": "two" },
 603           { "@value": "three", "@language": "en" },
 604           { "@value": "four", "@language": "en" },
 605         );
 606         assertEquals([...tag.hiddenLabels()], ["four"]);
 607       });
 608     });
 609
 610     describe("::deleteInCanonTag", () => {
 611       it("[[Call]] does nothing if called with no arguments", () => {
 612         const canon = new Tag("CanonTag");
 613         canon.persist();
 614         const tag = new Tag("EntityTag");
 615         tag.addInCanonTag(canon);
 616         tag.deleteInCanonTag();
 617         assertEquals(
 618           Array.from(tag.inCanonTags(), ($) => $.identifier),
 619           [canon.identifier],
 620         );
 621       });
 622
 623       it("[[Call]] deletes only the provided canon tags", () => {
 624         const canon = new Tag("CanonTag");
 625         canon.persist();
 626         const canon2 = new Tag("CanonTag");
 627         canon2.persist();
 628         const tag = new Tag("EntityTag");
 629         tag.addInCanonTag(canon, canon2);
 630         tag.deleteInCanonTag(canon, "000-0000", "");
 631         assertEquals(
 632           Array.from(tag.inCanonTags(), ($) => $.identifier),
 633           [canon2.identifier],
 634         );
 635       });
 636     });
 637
 638     describe("::deleteInvolvesTag", () => {
 639       it("[[Call]] does nothing if called with no arguments", () => {
 640         const involved = new Tag();
 641         involved.persist();
 642         const tag = new Tag("ConceptualTag");
 643         tag.addInvolvesTag(involved);
 644         tag.deleteInvolvesTag();
 645         assertEquals(
 646           Array.from(tag.involvesTags(), ($) => $.identifier),
 647           [involved.identifier],
 648         );
 649       });
 650
 651       it("[[Call]] deletes only the provided involved tags", () => {
 652         const character = new Tag("CharacterTag");
 653         character.persist();
 654         const involved = new Tag("RelationshipTag");
 655         involved.addInvolvesTag(character);
 656         involved.persist();
 657         const involved2 = new Tag("RelationshipTag");
 658         involved2.addInvolvesTag(character);
 659         involved2.persist();
 660         const tag = new Tag("RelationshipTag");
 661         tag.addInvolvesTag(involved, involved2);
 662         tag.deleteInvolvesTag(involved, character, "000-0000", "");
 663         assertEquals(
 664           Array.from(tag.involvesTags(), ($) => $.identifier),
 665           [involved2.identifier],
 666         );
 667       });
 668     });
 669
 670     describe("::hasInCanonTags", () => {
 671       it("[[Call]] yields the persisted tags which have this tag in canon", () => {
 672         const canon = new Tag("CanonTag");
 673         canon.persist();
 674         const entity = new Tag("EntityTag");
 675         entity.addInCanonTag(canon);
 676         entity.persist();
 677         const entity2 = new Tag("EntityTag");
 678         entity2.addInCanonTag(canon);
 679         entity2.persist();
 680         const tag = Tag.fromIdentifier(canon.identifier); // reload
 681         assertEquals(
 682           Array.from(tag.hasInCanonTags(), ($) => $.identifier),
 683           [entity.identifier, entity2.identifier],
 684         );
 685       });
 686     });
 687
 688     // `::hiddenLabels` is tested by `::addHiddenLabel`.
 689
 690     // `::identifier` is tested by a `.fromIdentifier`.
 691
 692     // `::inCanonTags` is tested by `::addInCanonTag`.
 693
 694     describe("::involvedInTags", () => {
 695       it("[[Call]] yields the persisted tags which involve this tag", () => {
 696         const involved = new Tag();
 697         involved.persist();
 698         const conceptual = new Tag("ConceptualTag");
 699         conceptual.addInvolvesTag(involved);
 700         conceptual.persist();
 701         const conceptual2 = new Tag("ConceptualTag");
 702         conceptual2.addInvolvesTag(involved);
 703         conceptual2.persist();
 704         const tag = Tag.fromIdentifier(involved.identifier); // reload
 705         assertEquals(
 706           Array.from(tag.involvedInTags(), ($) => $.identifier),
 707           [conceptual.identifier, conceptual2.identifier],
 708         );
 709       });
 710     });
 711
 712     // `::involvesTags` is tested by `::addInvolvesTag`.
 713
 714     // `::iri` is tested by a `.fromIRI`.
 715
 716     // `::kind` is tested by the constructor.
 717
 718     describe("::narrowerTags", () => {
 719       it("[[Call]] yields the persisted tags which are narrower than this tag", () => {
 720         const broader = new Tag();
 721         broader.persist();
 722         const narrower = new Tag();
 723         narrower.addBroaderTag(broader);
 724         narrower.persist();
 725         const narrower2 = new Tag();
 726         narrower2.addBroaderTag(broader);
 727         narrower2.persist();
 728         const tag = Tag.fromIdentifier(broader.identifier); // reload
 729         assertEquals(
 730           Array.from(tag.narrowerTags(), ($) => $.identifier),
 731           [narrower.identifier, narrower2.identifier],
 732         );
 733       });
 734     });
 735
 736     describe("::narrowerTransitiveTags", () => {
 737       it("[[Call]] returns narrower tags transitively", () => {
 738         const broad = new Tag();
 739         broad.persist();
 740         const narrow = new Tag();
 741         narrow.addBroaderTag(broad);
 742         narrow.persist();
 743         const superNarrow = new Tag();
 744         superNarrow.addBroaderTag(narrow);
 745         superNarrow.persist();
 746         const tag = Tag.fromIdentifier(broad.identifier); // reload
 747         assertEquals(
 748           Array.from(
 749             tag.narrowerTransitiveTags(),
 750             ($) => $.identifier,
 751           ),
 752           [narrow.identifier, superNarrow.identifier],
 753         );
 754       });
 755
 756       it("[[Call]] cannot recurse infinitely", () => {
 757         const tag = new Tag();
 758         tag.persist();
 759         const broad = new Tag();
 760         broad.addBroaderTag(tag);
 761         broad.persist();
 762         tag.addBroaderTag(broad);
 763         tag.persist();
 764         assertEquals(
 765           Array.from(tag.broaderTransitiveTags(), ($) => $.identifier),
 766           [broad.identifier, tag.identifier],
 767         );
 768       });
 769     });
 770
 771     describe("::persist", () => {
 772       it("[[Call]] returns an object with expected properties if there were changes", () => {
 773         const tag = new Tag();
 774         const activity = tag.persist();
 775         assertObjectMatch(
 776           activity,
 777           {
 778             "@context":
 779               "https://ns.1024.gdn/Tagging/discovery.context.jsonld",
 780             context: system.iri,
 781             object: tag.iri,
 782           },
 783         );
 784         assertArrayIncludes(activity["@type"], ["TagActivity"]);
 785         assert("endTime" in activity);
 786       });
 787
 788       it("[[Call]] returns a Create activity with a type predicate for new objects", () => {
 789         const activity = new Tag().persist();
 790         assertEquals(activity["@type"], ["TagActivity", "Create"]);
 791         assertArrayIncludes(activity.states, [{
 792           predicate: "a",
 793           object: "Tag",
 794         }]);
 795       });
 796
 797       it("[[Call]] returns an Update activity for old objects", () => {
 798         const tag = new Tag();
 799         tag.persist();
 800         tag.prefLabel = "etaoin";
 801         const activity = tag.persist();
 802         assertEquals(activity["@type"], ["TagActivity", "Update"]);
 803       });
 804
 805       it("[[Call]] states and unstates changes", () => {
 806         const broader1 = new Tag();
 807         broader1.persist();
 808         const broader2 = new Tag();
 809         broader2.persist();
 810         const tag = new Tag();
 811         tag.addBroaderTag(broader1);
 812         tag.persist();
 813         tag.prefLabel = "etaoin";
 814         tag.deleteBroaderTag(broader1);
 815         tag.addBroaderTag(broader2);
 816         const activity = tag.persist();
 817         assertObjectMatch(activity, {
 818           unstates: [
 819             { predicate: "prefLabel", object: { "@value": "" } },
 820             { predicate: "broader", object: broader1.iri },
 821           ],
 822           states: [
 823             { predicate: "prefLabel", object: { "@value": "etaoin" } },
 824             { predicate: "broader", object: broader2.iri },
 825           ],
 826         });
 827       });
 828
 829       it("[[Call]] doesn’t state if there are no additions", () => {
 830         const tag = new Tag();
 831         tag.addAltLabel("etaoin");
 832         tag.persist();
 833         tag.deleteAltLabel("etaoin");
 834         const activity = tag.persist();
 835         assertFalse("state" in activity);
 836       });
 837
 838       it("[[Call]] doesn’t unstate if there are no removals", () => {
 839         const tag = new Tag();
 840         tag.persist();
 841         tag.addAltLabel("etaoin");
 842         const activity = tag.persist();
 843         assertFalse("unstate" in activity);
 844       });
 845
 846       it("[[Call]] returns null if no meaningful changes were made", () => {
 847         const tag = new Tag();
 848         tag.persist();
 849         const activity = tag.persist();
 850         assertStrictEquals(activity, null);
 851       });
 852
 853       it("[[Call]] returns undefined for a silent persist", () => {
 854         const broader = new Tag();
 855         broader.persist();
 856         const tag = new Tag();
 857         tag.prefLabel = "etaoin";
 858         tag.addBroaderTag(broader);
 859         assertStrictEquals(tag.persist(true), undefined);
 860       });
 861     });
 862
 863     describe("::prefLabel", () => {
 864       it("[[Set]] sets the preferred label", () => {
 865         const tag = new Tag();
 866         tag.prefLabel = "one";
 867         assertStrictEquals(tag.prefLabel, "one");
 868         tag.prefLabel = { "@value": "two" };
 869         assertStrictEquals(tag.prefLabel, "two");
 870         tag.prefLabel = { "@value": "three", "@language": "en" };
 871         assertEquals(
 872           { ...tag.prefLabel },
 873           { "@value": "three", "@language": "en" },
 874         );
 875       });
 876     });
 877
 878     // `::tagURI` is tested by a `.fromTagURI`.
 879
 880     describe("::taggingEntity", () => {
 881       it("[[Get]] returns the tagging entity of the tag system", () => {
 882         assertStrictEquals(
 883           new Tag().taggingEntity,
 884           system.taggingEntity,
 885         );
 886       });
 887     });
 888
 889     describe("::toString", () => {
 890       it("[[Get]] returns the string value of the preferred label", () => {
 891         const tag = new Tag();
 892         tag.prefLabel = { "@value": "etaoin", "@language": "zxx" };
 893         assertStrictEquals(tag.toString(), "etaoin");
 894       });
 895     });
 896
 897     // `::[Storage.toObject]` is tested by `::persist`.
 898   });
 899
 900   describe("::authorityName", () => {
 901     it("[[Get]] returns the authority name", () => {
 902       const system = new TagSystem("etaoin.example", "1972-12-31");
 903       assertStrictEquals(system.authorityName, "etaoin.example");
 904     });
 905   });
 906
 907   describe("::authorityName", () => {
 908     it("[[Get]] returns the date", () => {
 909       const system = new TagSystem("etaoin.example", "1972-12-31");
 910       assertStrictEquals(system.date, "1972-12-31");
 911     });
 912   });
 913
 914   describe("::identifiers", () => {
 915     it("[[Get]] yields the extant entities", () => {
 916       const system = new TagSystem("etaoin.example", "1972-12-31");
 917       const tags = new Set(function* () {
 918         let i = 0;
 919         while (i++ < 5) {
 920           // Generate 5 tags and remember their identifiers.
 921           const tag = new system.Tag();
 922           tag.persist();
 923           yield tag.identifier;
 924         }
 925       }());
 926       assertEquals(
 927         new Set(Array.from(system.entities(), ($) => $.identifier)),
 928         tags,
 929       );
 930     });
 931   });
 932
 933   describe("::identifier", () => {
 934     it("[[Get]] returns the identifier", () => {
 935       const system = new TagSystem("etaoin.example", "1972-12-31");
 936       assertStrictEquals(system.identifier, "");
 937       const system2 = new TagSystem(
 938         "etaoin.example",
 939         "1972-12-31",
 940         "etaoin",
 941       );
 942       assertStrictEquals(system2.identifier, "etaoin");
 943     });
 944   });
 945
 946   describe("::identifiers", () => {
 947     it("[[Get]] yields the identifiers in use", () => {
 948       const system = new TagSystem("etaoin.example", "1972-12-31");
 949       const tags = new Set(function* () {
 950         let i = 0;
 951         while (i++ < 5) {
 952           // Generate 5 tags and remember their identifiers.
 953           const tag = new system.Tag();
 954           tag.persist();
 955           yield tag.identifier;
 956         }
 957       }());
 958       assertEquals(new Set(system.identifiers()), tags);
 959     });
 960   });
 961
 962   describe("::iri", () => {
 963     it("[[Get]] returns the I·R·I", () => {
 964       const system = new TagSystem("etaoin.example", "1972-12-31");
 965       assertStrictEquals(
 966         system.iri,
 967         "https://etaoin.example/tag:etaoin.example,1972-12-31:",
 968       );
 969       const system2 = new TagSystem(
 970         "etaoin.example",
 971         "1972-12-31",
 972         "etaoin",
 973       );
 974       assertStrictEquals(
 975         system2.iri,
 976         "https://etaoin.example/tag:etaoin.example,1972-12-31:etaoin",
 977       );
 978     });
 979   });
 980
 981   describe("::tagURI", () => {
 982     it("[[Get]] returns the Tag U·R·I", () => {
 983       const system = new TagSystem("etaoin.example", "1972-12-31");
 984       assertStrictEquals(
 985         system.tagURI,
 986         "tag:etaoin.example,1972-12-31:",
 987       );
 988       const system2 = new TagSystem(
 989         "etaoin.example",
 990         "1972-12-31",
 991         "etaoin",
 992       );
 993       assertStrictEquals(
 994         system2.tagURI,
 995         "tag:etaoin.example,1972-12-31:etaoin",
 996       );
 997     });
 998   });
 999
1000   describe("::taggingEntity", () => {
1001     it("[[Get]] returns the tagging entity", () => {
1002       const system = new TagSystem("etaoin.example", "1972-12-31");
1003       assertStrictEquals(
1004         system.taggingEntity,
1005         "etaoin.example,1972-12-31",
1006       );
1007     });
1008   });
1009 });