begin adding NoInfer to fix mapping issue

ark/type/__tests__/object.bench.ts

@@ -29,3 +29,25 @@ bench("dictionary with optional keys", () => {
 bench("tuple", () => {
 	const tuple = type(["string[]", "number[]", ["boolean[]"]])
 }).types([3159, "instantiations"])
+
+bench("nested type invocations", () => {
+	const t = type({
+		foo: type({
+			bar: type({
+				zoo: "string[]"
+			})
+				.array()
+				.or("number"),
+			superBar: type([
+				type("string"),
+				type("number[]"),
+				type({ inner: type("boolean") })
+			])
+		})
+			.or({
+				baz: "string",
+				quux: "1 | 2 | 3"
+			})
+			.array()
+	})
+}).types([17173, "instantiations"])

ark/type/__tests__/objects/mapped.test.ts

@@ -15,20 +15,28 @@ contextualize(() => {
 		attest(t.expression).equals(original.expression)
 	})
 
-	it("change one value", () => {
+	it("change values", () => {
 		const original = type({
 			"foo?": "string",
 			bar: "number",
-			baz: "boolean"
+			baz: {
+				inner: "string"
+			}
 		})
-		const withNullableBar = original.map(prop => {
+
+		const t = original.map(prop => {
 			if (prop.key === "bar") {
-				// due to a TS bug, this has to be assigned to a variable,
-				// otherwise the | null is not inferred: https://github.com/arktypeio/arktype/issues/1132
-				const nullableBar = prop.value.or("null")
 				return {
 					key: prop.key,
-					value: nullableBar
+					value: prop.value.or("null")
+				}
+			}
+			if (prop.key === "baz") {
+				return {
+					key: prop.key,
+					value: prop.value.and({
+						intersectedInner: "number"
+					})
 				}
 			}
 			return prop
@@ -37,11 +45,14 @@ contextualize(() => {
 		const expected = type({
 			"foo?": "string",
 			bar: "number | null",
-			baz: "boolean"
+			baz: {
+				inner: "string",
+				intersectedInner: "number"
+			}
 		})
 
-		attest<typeof expected>(withNullableBar)
-		attest(withNullableBar.expression).equals(expected.expression)
+		attest<typeof expected>(t)
+		attest(t.expression).equals(expected.expression)
 	})
 
 	it("change optionality", () => {

ark/type/__tests__/pipe.test.ts

@@ -744,9 +744,6 @@ contextualize(() => {
 	{}
 >`)
 
-		const serializedMorphs =
-			t.internal.firstReferenceOfKindOrThrow("morph").serializedMorphs
-
 		attest(t.expression).snap(
 			"{ l: 1, n: (In: string /^(?!^-0$)-?(?:0|[1-9]\\d*)(?:\\.\\d*[1-9])?$/) => Out<number> } | { n: (In: string /^(?!^-0$)-?(?:0|[1-9]\\d*)(?:\\.\\d*[1-9])?$/) => Out<number>, r: 1 }"
 		)

ark/type/methods/base.ts

@@ -92,11 +92,11 @@ interface Type<out t = unknown, $ = {}>
 	// like "nested 'and' chained from morph on optional"
 	and<const def, r = type.infer<def, $>>(
 		def: type.validate<def, $>
-	): instantiateType<inferIntersection<t, r>, $>
+	): instantiateType<inferIntersection<t, NoInfer<r>>, $>
 
 	or<const def, r = type.infer<def, $>>(
 		def: type.validate<def, $>
-	): instantiateType<t | r, $>
+	): instantiateType<t | NoInfer<r>, $>
 
 	array(): ArrayType<t[], $>
 

ark/type/methods/instantiate.ts

@@ -9,6 +9,8 @@ import type { ObjectType } from "./object.ts"
 import type { StringType } from "./string.ts"
 import type { ValidatorType } from "./validator.ts"
 
+// NoInfer avoids return type inference that can lead to incorrect results
+// See: https://discord.com/channels/957797212103016458/1285420361415917680/1285545752172429312
 export type instantiateType<t, $> =
 	// if any branch of t is a MorphAst, instantiate it as a MorphType
 	[Extract<t, InferredMorph>] extends [anyOrNever] ?