Add Endpoint::getProbableRequestType() (#3507)

Complements #3504

Author: RobinTail

express-zod-api/src/diagnostics.ts

@@ -36,7 +36,7 @@ export class Diagnostics {
           if (entry[prop]) stack.push(...entry[prop]);
       }
     }
-    if (endpoint.requestType === "json") {
+    if (endpoint.getProbableRequestType() === "json") {
       const reason = findJsonIncompatible(endpoint.inputSchema, "input");
       if (reason) {
         this.logger.warn(

express-zod-api/src/documentation.ts

@@ -250,10 +250,7 @@ export class Documentation extends OpenApiBuilder {
             request,
             paramNames: R.pluck("name", depictedParams),
             schema: inputSchema,
-            mimeType:
-              method === "query" // @todo consider moving into the inheritor of Endpoint::requestType() when made
-                ? contentTypes.form // conventionally recommended for QUERY
-                : contentTypes[endpoint.requestType],
+            mimeType: contentTypes[endpoint.getProbableRequestType(method)],
             description: descriptions?.requestBody?.({
               method,
               path,

express-zod-api/src/endpoint.ts

@@ -74,11 +74,8 @@ export abstract class AbstractEndpoint {
   public abstract get scopes(): ReadonlyArray<string>;
   /** @internal */
   public abstract get tags(): ReadonlyArray<string>;
-  /**
-   * @internal
-   * @todo reconsider the purpose of this method, since parsers are global now
-   * */
-  public abstract get requestType(): ContentType;
+  /** @internal */
+  public abstract getProbableRequestType(method?: ClientMethod): ContentType;
   /** @internal */
   public abstract get isDeprecated(): boolean;
 }
@@ -89,6 +86,7 @@ export class Endpoint<
   CTX extends FlatObject,
 > extends AbstractEndpoint {
   readonly #def: ConstructorParameters<typeof Endpoint<IN, OUT, CTX>>[0];
+  #requestType?: ContentType;
 
   /** considered an expensive operation, only required for generators */
   #ensureOutputExamples = R.once(() => {
@@ -161,15 +159,18 @@ export class Endpoint<
   }
 
   /** @internal */
-  public override get requestType() {
-    const found = findRequestTypeDefiningSchema(this.#def.inputSchema);
-    if (found) {
-      const brand = getBrand(found);
-      if (brand === ezUploadBrand) return "upload";
-      if (brand === ezRawBrand) return "raw";
-      if (brand === ezFormBrand) return "form";
-    }
-    return "json";
+  public override getProbableRequestType(method?: ClientMethod) {
+    if (method === "query") return "form";
+    return (this.#requestType ??= (() => {
+      const found = findRequestTypeDefiningSchema(this.#def.inputSchema);
+      if (found) {
+        const brand = getBrand(found);
+        if (brand === ezUploadBrand) return "upload";
+        if (brand === ezRawBrand) return "raw";
+        if (brand === ezFormBrand) return "form";
+      }
+      return "json";
+    })());
   }
 
   /** @internal */

express-zod-api/tests/endpoint.spec.ts

@@ -367,7 +367,17 @@ describe("Endpoint", () => {
     });
   });
 
-  describe(".requestType", () => {
+  describe(".getProbableRequestType()", () => {
+    test("should return 'form' for QUERY method %#", () => {
+      const factory = new EndpointsFactory(defaultResultHandler);
+      const endpoint = factory.build({
+        input: ez.raw(),
+        output: z.object({}),
+        handler: vi.fn(),
+      });
+      expect(endpoint.getProbableRequestType()).toBe("raw");
+      expect(endpoint.getProbableRequestType("query")).toBe("form");
+    });
     test.each([
       { input: z.object({}), expected: "json" },
       { input: ez.raw(), expected: "raw" },
@@ -383,7 +393,7 @@ describe("Endpoint", () => {
           output: z.object({}),
           handler: vi.fn(),
         });
-        expect(endpoint.requestType).toEqual(expected);
+        expect(endpoint.getProbableRequestType()).toEqual(expected);
       },
     );
   });