[OAS] @kbn/config-schema conversion tests (#186879)

## Summary

Adds some (missing) tests to the config-schema -> OAS conversion logic.
Notably for the functions on the `OpenAPIConverter` interface:
`convert`, `convertPathParamaters` and `convertQuery`.

packages/kbn-router-to-openapispec/src/generate_oas.test.util.ts

@@ -8,32 +8,7 @@
 
 import { schema } from '@kbn/config-schema';
 import type { CoreVersionedRouter, Router } from '@kbn/core-http-router-server-internal';
-
-/** Intended to cover a wide set of schema configurations */
-export const testSchema = schema.object({
-  string: schema.string({ maxLength: 10, minLength: 1 }),
-  maybeNumber: schema.maybe(schema.number({ max: 1000, min: 1 })),
-  booleanDefault: schema.boolean({
-    defaultValue: true,
-    meta: {
-      description: 'defaults to to true',
-    },
-  }),
-  ipType: schema.ip({ versions: ['ipv4'] }),
-  literalType: schema.literal('literallythis'),
-  neverType: schema.never(),
-  map: schema.mapOf(schema.string(), schema.string()),
-  record: schema.recordOf(schema.string(), schema.string()),
-  union: schema.oneOf([
-    schema.string({ maxLength: 1, meta: { description: 'Union string' } }),
-    schema.number({ min: 0, meta: { description: 'Union number' } }),
-  ]),
-  uri: schema.uri({
-    scheme: ['prototest'],
-    defaultValue: () => 'prototest://something',
-  }),
-  any: schema.any({ meta: { description: 'any type' } }),
-});
+import { createLargeSchema } from './oas_converter/kbn_config_schema/lib.test.util';
 
 type RoutesMeta = ReturnType<Router['getRoutes']>[number];
 type VersionedRoutesMeta = ReturnType<CoreVersionedRouter['getRoutes']>[number];
@@ -67,7 +42,7 @@ export const getRouterDefaults = () => ({
       query: schema.object({
         page: schema.number({ max: 999, min: 1, defaultValue: 1, meta: { description: 'page' } }),
       }),
-      body: testSchema,
+      body: createLargeSchema(),
     },
     response: {
       200: {

packages/kbn-router-to-openapispec/src/oas_converter/kbn_config_schema/lib.test.ts

@@ -7,7 +7,169 @@
  */
 
 import { schema } from '@kbn/config-schema';
-import { is, isNullableObjectType, getParamSchema } from './lib';
+import {
+  is,
+  convert,
+  convertPathParameters,
+  convertQuery,
+  isNullableObjectType,
+  getParamSchema,
+} from './lib';
+
+import { createLargeSchema } from './lib.test.util';
+
+describe('convert', () => {
+  test('base case', () => {
+    expect(convert(createLargeSchema())).toEqual({
+      schema: {
+        additionalProperties: false,
+        properties: {
+          any: {},
+          booleanDefault: {
+            default: true,
+            description: 'defaults to to true',
+            type: 'boolean',
+          },
+          ipType: {
+            format: 'ipv4',
+            type: 'string',
+          },
+          literalType: {
+            enum: ['literallythis'],
+            type: 'string',
+          },
+          map: {
+            additionalProperties: {
+              type: 'string',
+            },
+            type: 'object',
+          },
+          maybeNumber: {
+            maximum: 1000,
+            minimum: 1,
+            type: 'number',
+          },
+          record: {
+            additionalProperties: {
+              type: 'string',
+            },
+            type: 'object',
+          },
+          string: {
+            maxLength: 10,
+            minLength: 1,
+            type: 'string',
+          },
+          union: {
+            anyOf: [
+              {
+                description: 'Union string',
+                maxLength: 1,
+                type: 'string',
+              },
+              {
+                description: 'Union number',
+                minimum: 0,
+                type: 'number',
+              },
+            ],
+          },
+          uri: {
+            default: 'prototest://something',
+            format: 'uri',
+            type: 'string',
+          },
+        },
+        required: ['string', 'ipType', 'literalType', 'map', 'record', 'union', 'any'],
+        type: 'object',
+      },
+      shared: {},
+    });
+  });
+
+  test('shared schemas', () => {
+    const idSchema = schema.object({ a: schema.string() }, { meta: { id: 'myId' } });
+    const otherSchema = schema.object({ id: idSchema });
+    expect(convert(otherSchema)).toEqual({
+      schema: {
+        additionalProperties: false,
+        properties: {
+          id: {
+            $ref: '#/components/schemas/myId',
+          },
+        },
+        required: ['id'],
+        type: 'object',
+      },
+      shared: {
+        myId: {
+          additionalProperties: false,
+          properties: {
+            a: {
+              type: 'string',
+            },
+          },
+          required: ['a'],
+          type: 'object',
+        },
+      },
+    });
+  });
+});
+
+describe('convertPathParameters', () => {
+  test('base conversion', () => {
+    expect(
+      convertPathParameters(schema.object({ a: schema.string() }), { a: { optional: false } })
+    ).toEqual({
+      params: [
+        {
+          in: 'path',
+          name: 'a',
+          required: true,
+          schema: {
+            type: 'string',
+          },
+        },
+      ],
+      shared: {},
+    });
+  });
+  test('conversion with refs is disallowed', () => {
+    const sharedSchema = schema.object({ a: schema.string() }, { meta: { id: 'myparams' } });
+    expect(() => convertPathParameters(sharedSchema, { a: { optional: false } })).toThrow(
+      /myparams.*not supported/
+    );
+  });
+  test('throws if known parameters not found', () => {
+    expect(() =>
+      convertPathParameters(schema.object({ b: schema.string() }), { a: { optional: false } })
+    ).toThrow(/Unknown parameter: b/);
+  });
+});
+
+describe('convertQuery', () => {
+  test('base conversion', () => {
+    expect(convertQuery(schema.object({ a: schema.string() }))).toEqual({
+      query: [
+        {
+          in: 'query',
+          name: 'a',
+          required: true,
+          schema: {
+            type: 'string',
+          },
+        },
+      ],
+      shared: {},
+    });
+  });
+
+  test('conversion with refs is disallowed', () => {
+    const sharedSchema = schema.object({ a: schema.string() }, { meta: { id: 'myparams' } });
+    expect(() => convertQuery(sharedSchema)).toThrow(/myparams.*not supported/);
+  });
+});
 
 describe('is', () => {
   test.each([

packages/kbn-router-to-openapispec/src/oas_converter/kbn_config_schema/lib.test.util.ts

@@ -0,0 +1,36 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { schema } from '@kbn/config-schema';
+
+export function createLargeSchema() {
+  return schema.object({
+    string: schema.string({ maxLength: 10, minLength: 1 }),
+    maybeNumber: schema.maybe(schema.number({ max: 1000, min: 1 })),
+    booleanDefault: schema.boolean({
+      defaultValue: true,
+      meta: {
+        description: 'defaults to to true',
+      },
+    }),
+    ipType: schema.ip({ versions: ['ipv4'] }),
+    literalType: schema.literal('literallythis'),
+    neverType: schema.never(),
+    map: schema.mapOf(schema.string(), schema.string()),
+    record: schema.recordOf(schema.string(), schema.string()),
+    union: schema.oneOf([
+      schema.string({ maxLength: 1, meta: { description: 'Union string' } }),
+      schema.number({ min: 0, meta: { description: 'Union number' } }),
+    ]),
+    uri: schema.uri({
+      scheme: ['prototest'],
+      defaultValue: () => 'prototest://something',
+    }),
+    any: schema.any({ meta: { description: 'any type' } }),
+  });
+}

packages/kbn-router-to-openapispec/src/oas_converter/kbn_config_schema/lib.ts

@@ -94,7 +94,11 @@ const convertObjectMembersToParameterObjects = (
     const anyOf = (result as OpenAPIV3.SchemaObject).anyOf as OpenAPIV3.SchemaObject[];
     properties = anyOf.find((s) => s.type === 'object')!.properties!;
   } else if (isObjectType(schema)) {
-    const { result } = parse({ schema, ctx }) as { result: OpenAPIV3.SchemaObject };
+    const { result } = parse({ schema, ctx });
+    if ('$ref' in result)
+      throw new Error(
+        `Found a reference to "${result.$ref}". Runtime types with IDs are not supported in path or query parameters.`
+      );
     properties = (result as OpenAPIV3.SchemaObject).properties!;
     (result.required ?? []).forEach((key) => required.set(key, true));
   } else if (isRecordType(schema)) {