Add first business article and article layout

node_modules/zod/src/v4/classic/tests/from-json-schema.test.ts

@@ -0,0 +1,895 @@
+import { expect, test } from "vitest";
+import { fromJSONSchema } from "../from-json-schema.js";
+import * as z from "../index.js";
+
+test("basic string schema", () => {
+  const schema = fromJSONSchema({ type: "string" });
+  expect(schema.parse("hello")).toBe("hello");
+  expect(() => schema.parse(123)).toThrow();
+});
+
+test("string with constraints", () => {
+  const schema = fromJSONSchema({
+    type: "string",
+    minLength: 3,
+    maxLength: 10,
+    pattern: "^[a-z]+$",
+  });
+  expect(schema.parse("hello")).toBe("hello");
+  expect(schema.parse("helloworld")).toBe("helloworld"); // exactly 10 chars - valid
+  expect(() => schema.parse("hi")).toThrow(); // too short
+  expect(() => schema.parse("helloworld1")).toThrow(); // too long (11 chars)
+  expect(() => schema.parse("Hello")).toThrow(); // pattern mismatch
+});
+
+test("pattern is not implicitly anchored", () => {
+  // JSON Schema patterns match anywhere in the string, not just the full string
+  const schema = fromJSONSchema({
+    type: "string",
+    pattern: "foo",
+  });
+  expect(schema.parse("foo")).toBe("foo");
+  expect(schema.parse("foobar")).toBe("foobar"); // matches at start
+  expect(schema.parse("barfoo")).toBe("barfoo"); // matches at end
+  expect(schema.parse("barfoobar")).toBe("barfoobar"); // matches in middle
+  expect(() => schema.parse("bar")).toThrow(); // no match
+});
+
+test("number schema", () => {
+  const schema = fromJSONSchema({ type: "number" });
+  expect(schema.parse(42)).toBe(42);
+  expect(() => schema.parse("42")).toThrow();
+});
+
+test("number with constraints", () => {
+  const schema = fromJSONSchema({
+    type: "number",
+    minimum: 0,
+    maximum: 100,
+    multipleOf: 5,
+  });
+  expect(schema.parse(50)).toBe(50);
+  expect(() => schema.parse(-1)).toThrow();
+  expect(() => schema.parse(101)).toThrow();
+  expect(() => schema.parse(47)).toThrow(); // not multiple of 5
+});
+
+test("integer schema", () => {
+  const schema = fromJSONSchema({ type: "integer" });
+  expect(schema.parse(42)).toBe(42);
+  expect(() => schema.parse(42.5)).toThrow();
+});
+
+test("boolean schema", () => {
+  const schema = fromJSONSchema({ type: "boolean" });
+  expect(schema.parse(true)).toBe(true);
+  expect(schema.parse(false)).toBe(false);
+  expect(() => schema.parse("true")).toThrow();
+});
+
+test("null schema", () => {
+  const schema = fromJSONSchema({ type: "null" });
+  expect(schema.parse(null)).toBe(null);
+  expect(() => schema.parse(undefined)).toThrow();
+});
+
+test("object schema", () => {
+  const schema = fromJSONSchema({
+    type: "object",
+    properties: {
+      name: { type: "string" },
+      age: { type: "number" },
+    },
+    required: ["name"],
+  });
+  expect(schema.parse({ name: "John", age: 30 })).toEqual({ name: "John", age: 30 });
+  expect(schema.parse({ name: "John" })).toEqual({ name: "John" });
+  expect(() => schema.parse({ age: 30 })).toThrow(); // missing required
+});
+
+test("object with additionalProperties false", () => {
+  const schema = fromJSONSchema({
+    type: "object",
+    properties: {
+      name: { type: "string" },
+    },
+    additionalProperties: false,
+  });
+  expect(schema.parse({ name: "John" })).toEqual({ name: "John" });
+  expect(() => schema.parse({ name: "John", extra: "field" })).toThrow();
+});
+
+test("array schema", () => {
+  const schema = fromJSONSchema({
+    type: "array",
+    items: { type: "string" },
+  });
+  expect(schema.parse(["a", "b", "c"])).toEqual(["a", "b", "c"]);
+  expect(() => schema.parse([1, 2, 3])).toThrow();
+});
+
+test("array with constraints", () => {
+  const schema = fromJSONSchema({
+    type: "array",
+    items: { type: "number" },
+    minItems: 2,
+    maxItems: 4,
+  });
+  expect(schema.parse([1, 2])).toEqual([1, 2]);
+  expect(schema.parse([1, 2, 3, 4])).toEqual([1, 2, 3, 4]);
+  expect(() => schema.parse([1])).toThrow();
+  expect(() => schema.parse([1, 2, 3, 4, 5])).toThrow();
+});
+
+test("tuple with prefixItems (draft-2020-12)", () => {
+  const schema = fromJSONSchema({
+    $schema: "https://json-schema.org/draft/2020-12/schema",
+    type: "array",
+    prefixItems: [{ type: "string" }, { type: "number" }],
+  });
+  expect(schema.parse(["hello", 42])).toEqual(["hello", 42]);
+  expect(() => schema.parse(["hello"])).toThrow();
+  expect(() => schema.parse(["hello", "world"])).toThrow();
+});
+
+test("tuple with items array (draft-7)", () => {
+  const schema = fromJSONSchema({
+    $schema: "http://json-schema.org/draft-07/schema#",
+    type: "array",
+    items: [{ type: "string" }, { type: "number" }],
+    additionalItems: false,
+  });
+  expect(schema.parse(["hello", 42])).toEqual(["hello", 42]);
+  expect(() => schema.parse(["hello", 42, "extra"])).toThrow();
+});
+
+test("enum schema", () => {
+  const schema = fromJSONSchema({
+    enum: ["red", "green", "blue"],
+  });
+  expect(schema.parse("red")).toBe("red");
+  expect(() => schema.parse("yellow")).toThrow();
+});
+
+test("const schema", () => {
+  const schema = fromJSONSchema({
+    const: "hello",
+  });
+  expect(schema.parse("hello")).toBe("hello");
+  expect(() => schema.parse("world")).toThrow();
+});
+
+test("anyOf schema", () => {
+  const schema = fromJSONSchema({
+    anyOf: [{ type: "string" }, { type: "number" }],
+  });
+  expect(schema.parse("hello")).toBe("hello");
+  expect(schema.parse(42)).toBe(42);
+  expect(() => schema.parse(true)).toThrow();
+});
+
+test("allOf schema", () => {
+  const schema = fromJSONSchema({
+    allOf: [
+      { type: "object", properties: { name: { type: "string" } }, required: ["name"] },
+      { type: "object", properties: { age: { type: "number" } }, required: ["age"] },
+    ],
+  });
+  const result = schema.parse({ name: "John", age: 30 }) as { name: string; age: number };
+  expect(result.name).toBe("John");
+  expect(result.age).toBe(30);
+});
+
+test("allOf with empty array", () => {
+  // Empty allOf without explicit type returns any
+  const schema1 = fromJSONSchema({
+    allOf: [],
+  });
+  expect(schema1.parse("hello")).toBe("hello");
+  expect(schema1.parse(123)).toBe(123);
+  expect(schema1.parse({})).toEqual({});
+
+  // Empty allOf with explicit type returns base schema
+  const schema2 = fromJSONSchema({
+    type: "string",
+    allOf: [],
+  });
+  expect(schema2.parse("hello")).toBe("hello");
+  expect(() => schema2.parse(123)).toThrow();
+});
+
+test("oneOf schema (exclusive union)", () => {
+  const schema = fromJSONSchema({
+    oneOf: [{ type: "string" }, { type: "number" }],
+  });
+  expect(schema.parse("hello")).toBe("hello");
+  expect(schema.parse(42)).toBe(42);
+  expect(() => schema.parse(true)).toThrow();
+});
+
+test("type with anyOf creates intersection", () => {
+  // type: string AND (type:string,minLength:5 OR type:string,pattern:^a)
+  const schema = fromJSONSchema({
+    type: "string",
+    anyOf: [
+      { type: "string", minLength: 5 },
+      { type: "string", pattern: "^a" },
+    ],
+  });
+  // Should pass: string AND (minLength:5 OR pattern:^a) - matches minLength
+  expect(schema.parse("hello")).toBe("hello");
+  // Should pass: string AND (minLength:5 OR pattern:^a) - matches pattern
+  expect(schema.parse("abc")).toBe("abc");
+  // Should fail: string but neither minLength nor pattern match
+  expect(() => schema.parse("hi")).toThrow();
+  // Should fail: not a string
+  expect(() => schema.parse(123)).toThrow();
+});
+
+test("type with oneOf creates intersection", () => {
+  // type: string AND (exactly one of: type:string,minLength:5 OR type:string,pattern:^a)
+  const schema = fromJSONSchema({
+    type: "string",
+    oneOf: [
+      { type: "string", minLength: 5 },
+      { type: "string", pattern: "^a" },
+    ],
+  });
+  // Should pass: string AND minLength:5 (exactly one match - "hello" length 5 >= 5, doesn't start with 'a')
+  expect(schema.parse("hello")).toBe("hello");
+  // Should pass: string AND pattern:^a (exactly one match - "abc" starts with 'a', length 3 < 5)
+  expect(schema.parse("abc")).toBe("abc");
+  // Should fail: string but neither match
+  expect(() => schema.parse("hi")).toThrow();
+  // Should fail: not a string
+  expect(() => schema.parse(123)).toThrow();
+  // Should fail: matches both (length >= 5 AND starts with 'a') - exclusive union fails
+  expect(() => schema.parse("apple")).toThrow();
+});
+
+test("unevaluatedItems throws error", () => {
+  expect(() => {
+    fromJSONSchema({
+      type: "array",
+      unevaluatedItems: false,
+    });
+  }).toThrow("unevaluatedItems is not supported");
+});
+
+test("unevaluatedProperties throws error", () => {
+  expect(() => {
+    fromJSONSchema({
+      type: "object",
+      unevaluatedProperties: false,
+    });
+  }).toThrow("unevaluatedProperties is not supported");
+});
+
+test("if/then/else throws error", () => {
+  expect(() => {
+    fromJSONSchema({
+      if: { type: "string" },
+      then: { type: "number" },
+    });
+  }).toThrow("Conditional schemas");
+});
+
+test("external $ref throws error", () => {
+  expect(() => {
+    fromJSONSchema({
+      $ref: "https://example.com/schema#/definitions/User",
+    });
+  }).toThrow("External $ref is not supported");
+});
+
+test("local $ref resolution", () => {
+  const schema = fromJSONSchema({
+    $defs: {
+      User: {
+        type: "object",
+        properties: {
+          name: { type: "string" },
+        },
+        required: ["name"],
+      },
+    },
+    $ref: "#/$defs/User",
+  });
+  expect(schema.parse({ name: "John" })).toEqual({ name: "John" });
+  expect(() => schema.parse({})).toThrow();
+});
+
+test("circular $ref with lazy", () => {
+  const schema = fromJSONSchema({
+    $defs: {
+      Node: {
+        type: "object",
+        properties: {
+          value: { type: "string" },
+          children: {
+            type: "array",
+            items: { $ref: "#/$defs/Node" },
+          },
+        },
+      },
+    },
+    $ref: "#/$defs/Node",
+  });
+  type Node = { value: string; children: Node[] };
+  const result = schema.parse({
+    value: "root",
+    children: [{ value: "child", children: [] }],
+  }) as Node;
+  expect(result.value).toBe("root");
+  expect(result.children[0]?.value).toBe("child");
+});
+
+test("patternProperties", () => {
+  const schema = fromJSONSchema({
+    type: "object",
+    patternProperties: {
+      "^S_": { type: "string" },
+    },
+  });
+  const result = schema.parse({ S_name: "John", S_age: "30" }) as Record<string, string>;
+  expect(result.S_name).toBe("John");
+  expect(result.S_age).toBe("30");
+});
+
+test("patternProperties with regular properties", () => {
+  // Note: When patternProperties is combined with properties, the intersection
+  // validates all keys against the pattern. This test uses a pattern that
+  // matches the regular property name as well.
+  const schema = fromJSONSchema({
+    type: "object",
+    properties: {
+      S_name: { type: "string" },
+    },
+    patternProperties: {
+      "^S_": { type: "string" },
+    },
+    required: ["S_name"],
+  });
+  const result = schema.parse({ S_name: "John", S_extra: "value" }) as Record<string, string>;
+  expect(result.S_name).toBe("John");
+  expect(result.S_extra).toBe("value");
+});
+
+test("multiple patternProperties", () => {
+  const schema = fromJSONSchema({
+    type: "object",
+    patternProperties: {
+      "^S_": { type: "string" },
+      "^N_": { type: "number" },
+    },
+  });
+  const result = schema.parse({ S_name: "John", N_count: 123 }) as Record<string, string | number>;
+  expect(result.S_name).toBe("John");
+  expect(result.N_count).toBe(123);
+  // Keys not matching any pattern should pass through
+  const result2 = schema.parse({ S_name: "John", N_count: 123, other: "value" }) as Record<string, string | number>;
+  expect(result2.other).toBe("value");
+});
+
+test("multiple overlapping patternProperties", () => {
+  // If a key matches multiple patterns, value must satisfy all schemas
+  const schema = fromJSONSchema({
+    type: "object",
+    patternProperties: {
+      "^S_": { type: "string" },
+      "^S_N": { type: "string", minLength: 3 },
+    },
+  });
+  // S_name matches ^S_ but not ^S_N
+  expect(schema.parse({ S_name: "John" })).toEqual({ S_name: "John" });
+  // S_N matches both patterns - must satisfy both (string with minLength 3)
+  expect(schema.parse({ S_N: "abc" })).toEqual({ S_N: "abc" });
+  expect(() => schema.parse({ S_N: "ab" })).toThrow(); // too short for ^S_N pattern
+});
+
+test("default value", () => {
+  const schema = fromJSONSchema({
+    type: "string",
+    default: "hello",
+  });
+  // Default is applied during parsing if value is missing/undefined
+  // This depends on Zod's default behavior
+  expect(schema.parse("world")).toBe("world");
+});
+
+test("description metadata", () => {
+  const schema = fromJSONSchema({
+    type: "string",
+    description: "A string value",
+  });
+  expect(schema.parse("hello")).toBe("hello");
+});
+
+test("version detection - draft-2020-12", () => {
+  const schema = fromJSONSchema({
+    $schema: "https://json-schema.org/draft/2020-12/schema",
+    type: "array",
+    prefixItems: [{ type: "string" }],
+  });
+  expect(schema.parse(["hello"])).toEqual(["hello"]);
+});
+
+test("version detection - draft-7", () => {
+  const schema = fromJSONSchema({
+    $schema: "http://json-schema.org/draft-07/schema#",
+    type: "array",
+    items: [{ type: "string" }],
+  });
+  expect(schema.parse(["hello"])).toEqual(["hello"]);
+});
+
+test("version detection - draft-4", () => {
+  const schema = fromJSONSchema({
+    $schema: "http://json-schema.org/draft-04/schema#",
+    type: "array",
+    items: [{ type: "string" }],
+  });
+  expect(schema.parse(["hello"])).toEqual(["hello"]);
+});
+
+test("default version (draft-2020-12)", () => {
+  const schema = fromJSONSchema({
+    type: "array",
+    prefixItems: [{ type: "string" }],
+  });
+  expect(schema.parse(["hello"])).toEqual(["hello"]);
+});
+
+test("string format - email", () => {
+  const schema = fromJSONSchema({
+    type: "string",
+    format: "email",
+  });
+  expect(schema.parse("test@example.com")).toBe("test@example.com");
+});
+
+test("string format - uuid", () => {
+  const schema = fromJSONSchema({
+    type: "string",
+    format: "uuid",
+  });
+  const uuid = "550e8400-e29b-41d4-a716-446655440000";
+  expect(schema.parse(uuid)).toBe(uuid);
+});
+
+test("exclusiveMinimum and exclusiveMaximum", () => {
+  const schema = fromJSONSchema({
+    type: "number",
+    exclusiveMinimum: 0,
+    exclusiveMaximum: 100,
+  });
+  expect(schema.parse(50)).toBe(50);
+  expect(() => schema.parse(0)).toThrow();
+  expect(() => schema.parse(100)).toThrow();
+});
+
+test("boolean schema (true/false)", () => {
+  const trueSchema = fromJSONSchema(true);
+  expect(trueSchema.parse("anything")).toBe("anything");
+
+  const falseSchema = fromJSONSchema(false);
+  expect(() => falseSchema.parse("anything")).toThrow();
+});
+
+test("empty object schema", () => {
+  const schema = fromJSONSchema({
+    type: "object",
+  });
+  expect(schema.parse({})).toEqual({});
+  expect(schema.parse({ extra: "field" })).toEqual({ extra: "field" });
+});
+
+test("array without items", () => {
+  const schema = fromJSONSchema({
+    type: "array",
+  });
+  expect(schema.parse([1, "string", true])).toEqual([1, "string", true]);
+});
+
+test("mixed enum types", () => {
+  const schema = fromJSONSchema({
+    enum: ["string", 42, true, null],
+  });
+  expect(schema.parse("string")).toBe("string");
+  expect(schema.parse(42)).toBe(42);
+  expect(schema.parse(true)).toBe(true);
+  expect(schema.parse(null)).toBe(null);
+});
+
+test("nullable in OpenAPI 3.0", () => {
+  // General nullable case (not just enum: [null])
+  const stringSchema = fromJSONSchema(
+    {
+      type: "string",
+      nullable: true,
+    },
+    { defaultTarget: "openapi-3.0" }
+  );
+  expect(stringSchema.parse("hello")).toBe("hello");
+  expect(stringSchema.parse(null)).toBe(null);
+  expect(() => stringSchema.parse(123)).toThrow();
+
+  const numberSchema = fromJSONSchema(
+    {
+      type: "number",
+      nullable: true,
+    },
+    { defaultTarget: "openapi-3.0" }
+  );
+  expect(numberSchema.parse(42)).toBe(42);
+  expect(numberSchema.parse(null)).toBe(null);
+  expect(() => numberSchema.parse("string")).toThrow();
+
+  const objectSchema = fromJSONSchema(
+    {
+      type: "object",
+      properties: { name: { type: "string" } },
+      nullable: true,
+    },
+    { defaultTarget: "openapi-3.0" }
+  );
+  expect(objectSchema.parse({ name: "John" })).toEqual({ name: "John" });
+  expect(objectSchema.parse(null)).toBe(null);
+});
+
+// Metadata extraction tests
+
+test("unrecognized keys stored in globalRegistry by default", () => {
+  const schema = fromJSONSchema({
+    type: "string",
+    title: "My String",
+    deprecated: true,
+    examples: ["hello", "world"],
+    "x-custom": "custom value",
+  });
+
+  const meta = z.globalRegistry.get(schema);
+  expect(meta).toBeDefined();
+  expect(meta?.title).toBe("My String");
+  expect(meta?.deprecated).toBe(true);
+  expect(meta?.examples).toEqual(["hello", "world"]);
+  expect((meta as any)?.["x-custom"]).toBe("custom value");
+
+  // Clean up
+  z.globalRegistry.remove(schema);
+});
+
+test("unrecognized keys stored in custom registry", () => {
+  const customRegistry = z.registry<{ title?: string; deprecated?: boolean }>();
+
+  const schema = fromJSONSchema(
+    {
+      type: "number",
+      title: "Age",
+      deprecated: true,
+    },
+    { registry: customRegistry }
+  );
+
+  // Should be in custom registry
+  const meta = customRegistry.get(schema);
+  expect(meta).toBeDefined();
+  expect(meta?.title).toBe("Age");
+  expect(meta?.deprecated).toBe(true);
+
+  // Should NOT be in globalRegistry
+  expect(z.globalRegistry.get(schema)).toBeUndefined();
+});
+
+test("$id and id are captured as metadata", () => {
+  const customRegistry = z.registry<{ $id?: string; id?: string }>();
+
+  const schema1 = fromJSONSchema(
+    {
+      $id: "https://example.com/schemas/user",
+      type: "object",
+    },
+    { registry: customRegistry }
+  );
+  expect(customRegistry.get(schema1)?.$id).toBe("https://example.com/schemas/user");
+
+  const schema2 = fromJSONSchema(
+    {
+      id: "legacy-id",
+      type: "string",
+    },
+    { registry: customRegistry }
+  );
+  expect(customRegistry.get(schema2)?.id).toBe("legacy-id");
+});
+
+test("x-* extension keys are captured as metadata", () => {
+  const customRegistry = z.registry<Record<string, unknown>>();
+
+  const schema = fromJSONSchema(
+    {
+      type: "string",
+      "x-openapi-example": "example value",
+      "x-internal": true,
+      "x-tags": ["api", "public"],
+    },
+    { registry: customRegistry }
+  );
+
+  const meta = customRegistry.get(schema);
+  expect(meta?.["x-openapi-example"]).toBe("example value");
+  expect(meta?.["x-internal"]).toBe(true);
+  expect(meta?.["x-tags"]).toEqual(["api", "public"]);
+});
+
+test("metadata on nested schemas", () => {
+  const customRegistry = z.registry<Record<string, unknown>>();
+
+  const parentSchema = fromJSONSchema(
+    {
+      type: "object",
+      title: "User",
+      properties: {
+        name: {
+          type: "string",
+          title: "Name",
+          "x-field-order": 1,
+        },
+        age: {
+          type: "number",
+          title: "Age",
+          deprecated: true,
+        },
+      },
+    },
+    { registry: customRegistry }
+  );
+
+  // Verify parent schema has its metadata
+  expect(customRegistry.get(parentSchema)?.title).toBe("User");
+
+  // We can't easily access nested schemas directly, but we can verify
+  // the registry is being used correctly by checking a separate schema
+  const simpleSchema = fromJSONSchema(
+    {
+      type: "string",
+      title: "Simple",
+    },
+    { registry: customRegistry }
+  );
+  expect(customRegistry.get(simpleSchema)?.title).toBe("Simple");
+});
+
+test("no metadata added when no unrecognized keys", () => {
+  const customRegistry = z.registry<Record<string, unknown>>();
+
+  const schema = fromJSONSchema(
+    {
+      type: "string",
+      minLength: 1,
+      maxLength: 100,
+      description: "A regular string",
+    },
+    { registry: customRegistry }
+  );
+
+  // description is handled via .describe(), so it shouldn't be in metadata
+  // All other keys are recognized, so no metadata should be added
+  expect(customRegistry.get(schema)).toBeUndefined();
+});
+
+test("writeOnly and examples are captured as metadata", () => {
+  const customRegistry = z.registry<{ writeOnly?: boolean; examples?: unknown[] }>();
+
+  const schema = fromJSONSchema(
+    {
+      type: "string",
+      writeOnly: true,
+      examples: ["password123", "secret"],
+    },
+    { registry: customRegistry }
+  );
+
+  const meta = customRegistry.get(schema);
+  expect(meta?.writeOnly).toBe(true);
+  expect(meta?.examples).toEqual(["password123", "secret"]);
+});
+
+test("$comment and $anchor are captured as metadata", () => {
+  const customRegistry = z.registry<{ $comment?: string; $anchor?: string }>();
+
+  const schema = fromJSONSchema(
+    {
+      type: "string",
+      $comment: "This is a developer note",
+      $anchor: "my-anchor",
+    },
+    { registry: customRegistry }
+  );
+
+  const meta = customRegistry.get(schema);
+  expect(meta?.$comment).toBe("This is a developer note");
+  expect(meta?.$anchor).toBe("my-anchor");
+});
+
+test("contentEncoding and contentMediaType are stored as metadata", () => {
+  const customRegistry = z.registry<{ contentEncoding?: string; contentMediaType?: string }>();
+
+  const schema = fromJSONSchema(
+    {
+      type: "string",
+      contentEncoding: "base64",
+      contentMediaType: "image/png",
+    },
+    { registry: customRegistry }
+  );
+
+  // Should just be a string schema
+  expect(schema.parse("aGVsbG8gd29ybGQ=")).toBe("aGVsbG8gd29ybGQ=");
+
+  // Content keywords should be in metadata
+  const meta = customRegistry.get(schema);
+  expect(meta?.contentEncoding).toBe("base64");
+  expect(meta?.contentMediaType).toBe("image/png");
+});
+
+test("description on enum schema is applied", () => {
+  const schema = fromJSONSchema({
+    enum: ["red", "green", "blue"],
+    description: "A color value",
+  });
+  expect(schema.description).toBe("A color value");
+  expect(schema.parse("red")).toBe("red");
+});
+
+test("description on const schema is applied", () => {
+  const schema = fromJSONSchema({
+    const: "hello",
+    description: "A greeting",
+  });
+  expect(schema.description).toBe("A greeting");
+  expect(schema.parse("hello")).toBe("hello");
+});
+
+test("description on not: {} (never) schema is applied", () => {
+  const schema = fromJSONSchema({
+    not: {},
+    description: "A never schema",
+  });
+  expect(schema.description).toBe("A never schema");
+  expect(() => schema.parse("anything")).toThrow();
+});
+
+test("default on enum schema is applied", () => {
+  const schema = fromJSONSchema({
+    enum: ["red", "green", "blue"],
+    default: "red",
+  });
+  expect(schema.parse(undefined)).toBe("red");
+});
+
+test("default on const schema is applied", () => {
+  const schema = fromJSONSchema({
+    const: "hello",
+    default: "hello",
+  });
+  expect(schema.parse(undefined)).toBe("hello");
+});
+
+test("description and default on enum schema are both applied", () => {
+  const schema = fromJSONSchema({
+    enum: ["red", "green", "blue"],
+    description: "A color value",
+    default: "red",
+  });
+  expect(schema.description).toBe("A color value");
+  expect(schema.parse(undefined)).toBe("red");
+  expect(schema.parse("green")).toBe("green");
+});
+
+test("description on type-array schema is applied", () => {
+  const schema = fromJSONSchema({
+    type: ["string", "number"],
+    description: "A string or number",
+  } as any);
+  expect(schema.description).toBe("A string or number");
+  expect(schema.parse("hello")).toBe("hello");
+  expect(schema.parse(42)).toBe(42);
+});
+
+test("default on type-array schema is applied", () => {
+  const schema = fromJSONSchema({
+    type: ["string", "number"],
+    default: "fallback",
+  } as any);
+  expect(schema.parse(undefined)).toBe("fallback");
+  expect(schema.parse("hello")).toBe("hello");
+  expect(schema.parse(42)).toBe(42);
+});
+
+test("description on schema with anyOf is applied to the outer schema", () => {
+  const schema = fromJSONSchema({
+    description: "Either a string or a number",
+    anyOf: [{ type: "string" }, { type: "number" }],
+  });
+  expect(schema.description).toBe("Either a string or a number");
+  expect(schema.parse("hello")).toBe("hello");
+  expect(schema.parse(42)).toBe(42);
+});
+
+test("default on schema with anyOf is applied to the outer schema", () => {
+  const schema = fromJSONSchema({
+    default: "fallback",
+    anyOf: [{ type: "string" }, { type: "number" }],
+  });
+  expect(schema.parse(undefined)).toBe("fallback");
+  expect(schema.parse(42)).toBe(42);
+});
+
+test("description and unrecognized metadata coexist on the same schema", () => {
+  const customRegistry = z.registry<{ "x-custom"?: string; description?: string }>();
+  const schema = fromJSONSchema(
+    {
+      type: "string",
+      description: "A custom string",
+      "x-custom": "value",
+    },
+    { registry: customRegistry }
+  );
+  expect(schema.description).toBe("A custom string");
+  expect(customRegistry.get(schema)?.["x-custom"]).toBe("value");
+});
+
+test("circular input throws a clear error", () => {
+  const person: any = {
+    type: "object",
+    properties: { name: { type: "string" } },
+    required: ["name"],
+  };
+  person.properties.bestFriend = person;
+  expect(() => fromJSONSchema(person)).toThrow(/not valid JSON/);
+});
+
+test("getter-based input that synthesizes a cycle throws", () => {
+  const root: any = { type: "object", properties: { name: { type: "string" } } };
+  Object.defineProperty(root.properties, "self", {
+    enumerable: true,
+    get() {
+      return root;
+    },
+  });
+  expect(() => fromJSONSchema(root)).toThrow(/not valid JSON/);
+});
+
+test("BigInt in input throws", () => {
+  const input: any = { type: "integer", minimum: 1n };
+  expect(() => fromJSONSchema(input)).toThrow(/not valid JSON/);
+});
+
+test("class-instance input is normalized to a plain object", () => {
+  class StringSchema {
+    type = "string" as const;
+    minLength = 2;
+  }
+  const schema = fromJSONSchema(new StringSchema() as any);
+  expect(schema.parse("hi")).toBe("hi");
+  expect(() => schema.parse("h")).toThrow();
+});
+
+test("getter-based properties are materialized", () => {
+  const input: any = { type: "object", properties: {}, required: [] };
+  Object.defineProperty(input.properties, "name", {
+    enumerable: true,
+    get() {
+      return { type: "string" };
+    },
+  });
+  const schema = fromJSONSchema(input);
+  expect(schema.parse({ name: "Alice" })).toEqual({ name: "Alice" });
+});
+
+test("Date default is coerced to its JSON string form", () => {
+  const date = new Date("2026-01-02T03:04:05.000Z");
+  const schema = fromJSONSchema({ type: "string", default: date as any });
+  expect(schema.parse(undefined)).toBe(date.toISOString());
+});