chore: fix type inference with different ways to define functions

Signed-off-by: benjdlambert <ben@blam.sh>

plugins/scaffolder-node/src/alpha/filters/createTemplateFilter.ts

@@ -14,8 +14,11 @@
  * limitations under the License.
  */
 
-import { JsonValue } from '@backstage/types';
-import { CreatedTemplateFilter, TemplateFilterSchema } from './types';
+import {
+  CreatedTemplateFilter,
+  TemplateFilterExample,
+  ZodFunctionSchema,
+} from './types';
 import { z } from 'zod';
 
 /**
@@ -23,10 +26,12 @@ import { z } from 'zod';
  * @alpha
  */
 export const createTemplateFilter = <
-  TSchema extends TemplateFilterSchema<any, any> | undefined,
-  TFilterSchema extends TSchema extends TemplateFilterSchema<any, any>
-    ? z.infer<ReturnType<TSchema>>
-    : (arg: JsonValue, ...rest: JsonValue[]) => JsonValue | undefined,
->(
-  filter: CreatedTemplateFilter<TSchema, TFilterSchema>,
-): CreatedTemplateFilter<TSchema, TFilterSchema> => filter;
+  TFunctionArgs extends [z.ZodTypeAny, ...z.ZodTypeAny[]],
+  TReturnType extends z.ZodTypeAny,
+>(options: {
+  id: string;
+  description?: string;
+  examples?: TemplateFilterExample[];
+  schema?: ZodFunctionSchema<TFunctionArgs, TReturnType>;
+  filter: (...args: z.infer<z.ZodTuple<TFunctionArgs>>) => z.infer<TReturnType>;
+}): CreatedTemplateFilter<TFunctionArgs, TReturnType> => options;

plugins/scaffolder-node/src/alpha/filters/types.ts

@@ -14,21 +14,9 @@
  * limitations under the License.
  */
 import { z } from 'zod';
-import { TemplateFilter } from '../../types';
-import { JsonValue } from '@backstage/types';
 
 export type { TemplateFilter } from '../../types';
 
-/** @alpha */
-export type TemplateFilterSchema<
-  Args extends z.ZodTuple<
-    | [z.ZodType<JsonValue>]
-    | [z.ZodType<JsonValue>, ...(z.ZodType<JsonValue> | z.ZodUnknown)[]],
-    z.ZodType<JsonValue> | z.ZodUnknown | null
-  >,
-  Result extends z.ZodType<JsonValue> | z.ZodUndefined,
-> = (zod: typeof z) => z.ZodFunction<Args, Result>;
-
 /** @alpha */
 export type TemplateFilterExample = {
   description?: string;
@@ -36,25 +24,29 @@ export type TemplateFilterExample = {
   notes?: string;
 };
 
+/**
+ * Type for template filter schema functions that supports both Zod function definition methods:
+ * @alpha
+ */
+export type ZodFunctionSchema<
+  TFunctionArgs extends [z.ZodTypeAny, ...z.ZodTypeAny[]],
+  TReturnType extends z.ZodTypeAny,
+> = (
+  zod: typeof z,
+) =>
+  | z.ZodFunction<z.ZodTuple<TFunctionArgs, null>, TReturnType>
+  | z.ZodType<
+      (...args: z.infer<z.ZodTuple<TFunctionArgs>>) => z.infer<TReturnType>
+    >;
+
 /** @alpha */
 export type CreatedTemplateFilter<
-  TSchema extends
-    | TemplateFilterSchema<any, any>
-    | undefined
-    | unknown = unknown,
-  TFilterSchema extends TSchema extends TemplateFilterSchema<any, any>
-    ? z.infer<ReturnType<TSchema>>
-    : TSchema extends unknown
-    ? unknown
-    : TemplateFilter = TSchema extends TemplateFilterSchema<any, any>
-    ? z.infer<ReturnType<TSchema>>
-    : TSchema extends unknown
-    ? unknown
-    : TemplateFilter,
+  TFunctionArgs extends [z.ZodTypeAny, ...z.ZodTypeAny[]],
+  TReturnType extends z.ZodTypeAny,
 > = {
   id: string;
   description?: string;
   examples?: TemplateFilterExample[];
-  schema?: TSchema;
-  filter: TFilterSchema;
+  schema?: ZodFunctionSchema<TFunctionArgs, TReturnType>;
+  filter: (...args: z.infer<z.ZodTuple<TFunctionArgs>>) => z.infer<TReturnType>;
 };

plugins/scaffolder-node/src/alpha/globals/createTemplateGlobal.ts

@@ -18,9 +18,9 @@ import { z } from 'zod';
 import {
   CreatedTemplateGlobalFunction,
   CreatedTemplateGlobalValue,
-  TemplateGlobalFunctionSchema,
+  TemplateGlobalFunctionExample,
 } from './types';
-import { JsonValue } from '@backstage/types';
+import { ZodFunctionSchema } from '../filters';
 
 /**
  * This function is used to create new template global values in type-safe manner.
@@ -39,10 +39,12 @@ export const createTemplateGlobalValue = (
  * @alpha
  */
 export const createTemplateGlobalFunction = <
-  TSchema extends TemplateGlobalFunctionSchema<any, any> | undefined,
-  TFilterSchema extends TSchema extends TemplateGlobalFunctionSchema<any, any>
-    ? z.infer<ReturnType<TSchema>>
-    : (...args: JsonValue[]) => JsonValue | undefined,
->(
-  fn: CreatedTemplateGlobalFunction<TSchema, TFilterSchema>,
-): CreatedTemplateGlobalFunction<TSchema, TFilterSchema> => fn;
+  TFunctionArgs extends [z.ZodTypeAny, ...z.ZodTypeAny[]],
+  TReturnType extends z.ZodTypeAny,
+>(options: {
+  id: string;
+  description?: string;
+  examples?: TemplateGlobalFunctionExample[];
+  schema?: ZodFunctionSchema<TFunctionArgs, TReturnType>;
+  fn: (...args: z.infer<z.ZodTuple<TFunctionArgs>>) => z.infer<TReturnType>;
+}): CreatedTemplateGlobalFunction<TFunctionArgs, TReturnType> => options;

plugins/scaffolder-node/src/alpha/globals/types.ts

@@ -15,7 +15,7 @@
  */
 import { JsonValue } from '@backstage/types';
 import { z } from 'zod';
-import { TemplateGlobal } from '../../types';
+import { ZodFunctionSchema } from '../filters/types';
 
 export type { TemplateGlobal } from '../../types';
 
@@ -26,15 +26,6 @@ export type CreatedTemplateGlobalValue<T extends JsonValue = JsonValue> = {
   description?: string;
 };
 
-/** @alpha */
-export type TemplateGlobalFunctionSchema<
-  Args extends z.ZodTuple<
-    [] | [z.ZodType<JsonValue>, ...(z.ZodType<JsonValue> | z.ZodUnknown)[]],
-    z.ZodType<JsonValue> | z.ZodUnknown | null
-  >,
-  Result extends z.ZodType<JsonValue> | z.ZodUndefined,
-> = (zod: typeof z) => z.ZodFunction<Args, Result>;
-
 /** @alpha */
 export type TemplateGlobalFunctionExample = {
   description?: string;
@@ -44,31 +35,17 @@ export type TemplateGlobalFunctionExample = {
 
 /** @alpha */
 export type CreatedTemplateGlobalFunction<
-  TSchema extends
-    | TemplateGlobalFunctionSchema<any, any>
-    | undefined
-    | unknown = unknown,
-  TFilterSchema extends TSchema extends TemplateGlobalFunctionSchema<any, any>
-    ? z.infer<ReturnType<TSchema>>
-    : TSchema extends unknown
-    ? unknown
-    : Exclude<
-        TemplateGlobal,
-        JsonValue
-      > = TSchema extends TemplateGlobalFunctionSchema<any, any>
-    ? z.infer<ReturnType<TSchema>>
-    : TSchema extends unknown
-    ? unknown
-    : Exclude<TemplateGlobal, JsonValue>,
+  TFunctionArgs extends [z.ZodTypeAny, ...z.ZodTypeAny[]],
+  TReturnType extends z.ZodTypeAny,
 > = {
   id: string;
   description?: string;
   examples?: TemplateGlobalFunctionExample[];
-  schema?: TSchema;
-  fn: TFilterSchema;
+  schema?: ZodFunctionSchema<TFunctionArgs, TReturnType>;
+  fn: (...args: z.infer<z.ZodTuple<TFunctionArgs>>) => z.infer<TReturnType>;
 };
 
 /** @alpha */
 export type CreatedTemplateGlobal =
   | CreatedTemplateGlobalValue
-  | CreatedTemplateGlobalFunction<unknown, unknown>;
+  | CreatedTemplateGlobalFunction<any, any>;

plugins/scaffolder-node/src/alpha/index.ts

@@ -73,9 +73,7 @@ export const scaffolderTaskBrokerExtensionPoint =
  */
 export interface ScaffolderTemplatingExtensionPoint {
   addTemplateFilters(
-    filters:
-      | Record<string, TemplateFilter>
-      | CreatedTemplateFilter<unknown, unknown>[],
+    filters: Record<string, TemplateFilter> | CreatedTemplateFilter<any, any>[],
   ): void;
 
   addTemplateGlobals(