test(v4): toJSONSchema - use validateOpenAPI30Schema in all relevant scenarios (#5163)

Author: marcalexiei

packages/zod/src/v4/classic/tests/to-json-schema.test.ts

@@ -580,7 +580,10 @@ describe("toJSONSchema", () => {
  });
 
  test("nullable openapi-3.0", () => {
- expect(z.toJSONSchema(z.string().nullable(), { target: "openapi-3.0" })).toMatchInlineSnapshot(`
+ const schema = z.string().nullable();
+ const jsonSchema = z.toJSONSchema(schema, { target: "openapi-3.0" });
+ validateOpenAPI30Schema(jsonSchema);
+ expect(jsonSchema).toMatchInlineSnapshot(`
  {
  "nullable": true,
  "type": "string",
@@ -590,7 +593,9 @@ describe("toJSONSchema", () => {
 
  test("union with null openapi-3.0", () => {
  const schema = z.union([z.string(), z.null()]);
- expect(z.toJSONSchema(schema, { target: "openapi-3.0" })).toMatchInlineSnapshot(`
+ const jsonSchema = z.toJSONSchema(schema, { target: "openapi-3.0" });
+ validateOpenAPI30Schema(jsonSchema);
+ expect(jsonSchema).toMatchInlineSnapshot(`
  {
  "anyOf": [
  {
@@ -610,7 +615,9 @@ describe("toJSONSchema", () => {
 
  test("number with exclusive min-max openapi-3.0", () => {
  const schema = z.number().lt(100).gt(1);
- expect(z.toJSONSchema(schema, { target: "openapi-3.0" })).toMatchInlineSnapshot(`
+ const jsonSchema = z.toJSONSchema(schema, { target: "openapi-3.0" });
+ validateOpenAPI30Schema(jsonSchema);
+ expect(jsonSchema).toMatchInlineSnapshot(`
  {
  "exclusiveMaximum": true,
  "exclusiveMinimum": true,
@@ -704,7 +711,9 @@ describe("toJSONSchema", () => {
 
  test("record openapi-3.0", () => {
  const schema = z.record(z.string(), z.boolean());
- expect(z.toJSONSchema(schema, { target: "openapi-3.0" })).toMatchInlineSnapshot(`
+ const jsonSchema = z.toJSONSchema(schema, { target: "openapi-3.0" });
+ validateOpenAPI30Schema(jsonSchema);
+ expect(jsonSchema).toMatchInlineSnapshot(`
  {
  "additionalProperties": {
  "type": "boolean",