Merge pull request #1691 from raunak-rpm/fix/macro-function-inference-1574

fix: named macros with function syntax now infer previous macro resolve types (#1574)

Author: SaltyAom

src/index.ts

@@ -5261,6 +5261,126 @@ export default class Elysia<
 		return this
 	}
 
+	// Overload 1: Named macro with function syntax (fixes issue #1574)
+	// This overload handles: .macro("name", (param) => ({ resolve: ... }))
+	// For function syntax, we compute MacroContext from ALL previous macros
+	// because we can't infer which macros are selected before the function returns
+	macro<
+		const Name extends string,
+		// Compute MacroContext from all previous macros, assuming all are enabled
+		const MacroContext extends {} extends Metadata['macroFn']
+			? {}
+			: MacroToContext<
+					Metadata['macroFn'],
+					// Use all macro keys set to true to include all possible resolves
+					{ [K in keyof Metadata['macroFn']]: true },
+					Definitions['typebox']
+				>,
+		const Param,
+		const Property extends Metadata['macro'] &
+			MacroProperty<
+				Metadata['macro'] &
+					InputSchema<keyof Definitions['typebox'] & string> & {
+						[name in Name]?: boolean
+					},
+				MacroContext,
+				Singleton & {
+					derive: Partial<Ephemeral['derive'] & Volatile['derive']>
+					resolve: Partial<
+						Ephemeral['resolve'] & Volatile['resolve']
+					> &
+						// @ts-ignore
+						MacroContext['resolve']
+				},
+				Definitions['error']
+			>
+	>(
+		name: Name,
+		macro: (param: Param) => Property
+	): Elysia<
+		BasePath,
+		Singleton,
+		Definitions,
+		{
+			schema: Metadata['schema']
+			standaloneSchema: Metadata['standaloneSchema']
+			macro: Metadata['macro'] & {
+				[name in Name]?: Param
+			}
+			macroFn: Metadata['macroFn'] & {
+				[name in Name]: (param: Param) => Property
+			}
+			parser: Metadata['parser']
+			response: Metadata['response']
+		},
+		Routes,
+		Ephemeral,
+		Volatile
+	>
+
+	// Overload 2: Named macro with object syntax (original)
+	// This overload handles: .macro("name", { resolve: ... })
+	macro<
+		const Name extends string,
+		const Input extends Metadata['macro'] &
+			InputSchema<keyof Definitions['typebox'] & string>,
+		const Schema extends MergeSchema<
+			UnwrapRoute<Input, Definitions['typebox'], BasePath>,
+			MergeSchema<
+				Volatile['schema'],
+				MergeSchema<Ephemeral['schema'], Metadata['schema']>
+			> &
+				Metadata['standaloneSchema'] &
+				Ephemeral['standaloneSchema'] &
+				Volatile['standaloneSchema']
+		>,
+		const MacroContext extends {} extends Metadata['macroFn']
+			? {}
+			: MacroToContext<
+					Metadata['macroFn'],
+					Omit<Input, NonResolvableMacroKey>,
+					Definitions['typebox']
+				>,
+		const Property extends MacroProperty<
+			Metadata['macro'] &
+				InputSchema<keyof Definitions['typebox'] & string> & {
+					[name in Name]?: boolean
+				},
+			Schema & MacroContext,
+			Singleton & {
+				derive: Partial<Ephemeral['derive'] & Volatile['derive']>
+				resolve: Partial<
+					Ephemeral['resolve'] & Volatile['resolve']
+				> &
+					// @ts-ignore
+					MacroContext['resolve']
+			},
+			Definitions['error']
+		>
+	>(
+		name: Name,
+		macro: (Input extends any ? Input : Prettify<Input>) & Property
+	): Elysia<
+		BasePath,
+		Singleton,
+		Definitions,
+		{
+			schema: Metadata['schema']
+			standaloneSchema: Metadata['standaloneSchema']
+			macro: Metadata['macro'] & {
+				[name in Name]?: boolean
+			}
+			macroFn: Metadata['macroFn'] & {
+				[name in Name]: Property
+			}
+			parser: Metadata['parser']
+			response: Metadata['response']
+		},
+		Routes,
+		Ephemeral,
+		Volatile
+	>
+
 	macro<
 		const Name extends string,
 		const Input extends Metadata['macro'] &
@@ -5415,7 +5535,10 @@ export default class Elysia<
 		Volatile
 	>
 
-	macro(macroOrName: string | Macro, macro?: Macro) {
+	macro(
+		macroOrName: string | Macro,
+		macro?: Macro | ((...args: any[]) => any)
+	) {
 		if (typeof macroOrName === 'string' && !macro)
 			throw new Error('Macro function is required')
 

test/macro/macro.test.ts

@@ -1438,4 +1438,35 @@ describe('Macro', () => {
 
 		expect(invalid3.status).toBe(422)
 	})
+
+	// Issue #1574: Named macros with function syntax should infer previous macro resolve types
+	it('infer previous macro resolve in function syntax (issue #1574)', async () => {
+		const app = new Elysia()
+			.macro('auth', {
+				resolve: () => ({
+					user: 'authenticated-user' as const
+				})
+			})
+			.macro('permission', (permission: string) => ({
+				auth: true,
+				// The 'user' type should be inferred from the 'auth' macro's resolve
+				resolve: ({ user }) => ({
+					permission,
+					userFromAuth: user
+				})
+			}))
+			.get('/', ({ userFromAuth, permission }) => ({
+				user: userFromAuth,
+				permission
+			}), {
+				permission: 'admin'
+			})
+
+		const response = await app.handle(req('/')).then((x) => x.json())
+
+		expect(response).toEqual({
+			user: 'authenticated-user',
+			permission: 'admin'
+		})
+	})
 })