fix: ensure nested morph intersections preserve normalized type struc…

…ture (#1180)

ark/repo/scratch.ts

@@ -1,3 +1,5 @@
 import { type } from "arktype"
 
-const t = type("string.numeric.parse")
+const t = type({
+	foo: "string"
+})

ark/schema/package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@ark/schema",
-	"version": "0.18.0",
+	"version": "0.19.0",
 	"license": "MIT",
 	"author": {
 		"name": "David Blass",

ark/schema/roots/morph.ts

@@ -129,16 +129,16 @@ const implementation: nodeImplementationOf<Morph.Declaration> =
 				)
 			},
 			...defineRightwardIntersections("morph", (l, r, ctx) => {
-				const inTersection = intersectOrPipeNodes(l.in, r, ctx)
-				return inTersection instanceof Disjoint ? inTersection : (
-						inTersection.distribute(
-							branch => ({
-								...l.inner,
-								in: branch
-							}),
-							ctx.$.parseSchema
-						)
-					)
+				const inTersection =
+					l.inner.in ? intersectOrPipeNodes(l.inner.in, r, ctx) : r
+				return (
+					inTersection instanceof Disjoint ? inTersection
+					: inTersection.equals(l.inner.in) ? l
+					: ctx.$.node("morph", {
+							...l.inner,
+							in: inTersection
+						})
+				)
 			})
 		}
 	})

ark/schema/shared/intersections.ts

@@ -73,24 +73,18 @@ export const intersectOrPipeNodes: InternalNodeIntersection<IntersectionContext>
 
 		if (isPureIntersection && l.equals(r)) return l
 
-		let result: BaseNode | Disjoint | null
-
-		if (isPureIntersection) {
-			if (l.equals(r)) return l
-			result = _intersectNodes(l, r, ctx)
-		} else {
-			result =
-				l.hasKindIn(...rootKinds) ?
-					// if l is a RootNode, r will be as well
-					_pipeNodes(l, r as never, ctx)
-				:	_intersectNodes(l, r, ctx)
-		}
+		let result =
+			isPureIntersection ? _intersectNodes(l, r, ctx)
+			: l.hasKindIn(...rootKinds) ?
+				// if l is a RootNode, r will be as well
+				_pipeNodes(l, r as never, ctx)
+			:	_intersectNodes(l, r, ctx)
 
 		if (isNode(result)) {
 			// if the result equals one of the operands, preserve its metadata by
 			// returning the original reference
-			if (l.equals(result)) result = l as never
-			else if (r.equals(result)) result = r as never
+			if (l.equals(result)) result = l
+			else if (r.equals(result)) result = r
 		}
 
 		intersectionCache[lrCacheKey] = result

ark/type/__tests__/realWorld.test.ts

@@ -1009,4 +1009,19 @@ nospace must be matched by ^\\S*$ (was "One space")`)
 
 		attest(EitherInput(["str"])).snap(["str"])
 	})
+
+	it("intersecting unknown with piped type preserves identity", () => {
+		const base = type({
+			foo: type("string").pipe(() => 123)
+		})
+			.pipe(c => c)
+			.to({
+				foo: "123"
+			})
+
+		const identity = base.and("unknown")
+
+		attest(base.json).equals(identity.json)
+		attest(base.internal.id).equals(identity.internal.id)
+	})
 })

ark/type/package.json

@@ -1,7 +1,7 @@
 {
 	"name": "arktype",
 	"description": "TypeScript's 1:1 validator, optimized from editor to runtime",
-	"version": "2.0.0-rc.16",
+	"version": "2.0.0-rc.17",
 	"license": "MIT",
 	"author": {
 		"name": "David Blass",