Require opt-in to prevent it being a breaking change

edgedb · Sep 3, 2024 · b4dfe85 · b4dfe85
1 parent 7131057
commit b4dfe85
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Showing 2 changed files with 84 additions and 16 deletions.
diff --git a/integration-tests/lts/select.test.ts b/integration-tests/lts/select.test.ts
@@ -5,6 +5,14 @@ import * as $ from "../../packages/generate/src/syntax/reflection";
 import e, { type $infer } from "./dbschema/edgeql-js";
 import { setupTests, teardownTests, tc, type TestData } from "./setupTeardown";
 
+declare module "./dbschema/edgeql-js/typesystem" {
+  export interface SetTypesystemOptions {
+    future: {
+      polymorphismAsDiscriminatedUnions: true;
+    };
+  }
+}
+
 let client: edgedb.Client;
 let data: TestData;
 
@@ -239,7 +247,7 @@ describe("select", () => {
     assert.deepEqual(query.__element__.__kind__, $.TypeKind.object);
     assert.equal(query.__element__.__name__, "default::Person");
 
-    type result = $.BaseTypeToTsType<(typeof query)["__element__"]>;
+    type result = $infer<typeof query>[number];
     tc.assert<
       tc.IsExact<
         result,
@@ -294,21 +302,17 @@ describe("select", () => {
       }),
     }));
 
-    type q = $.setToTsType<typeof q>;
-    tc.assert<
-      tc.IsExact<
-        q,
-        ({
-          id: string;
-        } & (
-          | { __typename: "default::Hero"; secret_identity: string | null }
-          | {
-              __typename: "default::Villain";
-              nemesis: { id: string; computable: 1234 } | null;
-            }
-        ))[]
-      >
-    >(true);
+    type actual = $infer<typeof q>[number];
+    type expected = {
+      id: string;
+    } & (
+      | { __typename: "default::Hero"; secret_identity: string | null }
+      | {
+          __typename: "default::Villain";
+          nemesis: { id: string; computable: 1234 } | null;
+        }
+    );
+    tc.assert<tc.IsExact<actual, expected>>(true);
   });
 
   test("parent type props in polymorphic", () => {

diff --git a/packages/generate/src/syntax/typesystem.ts b/packages/generate/src/syntax/typesystem.ts
@@ -12,6 +12,25 @@ import type { cardutil } from "./cardinality";
 import type { Range, MultiRange } from "edgedb";
 import type { $Shape, normaliseShape } from "./select";
 
+/**
+ * Use declaration merging to set the {@link TypesystemOptions} via this
+ */
+// eslint-disable-next-line @typescript-eslint/no-empty-object-type
+export interface SetTypesystemOptions {}
+
+export type TypesystemOptions = {
+  future: {
+    /**
+     * Opt-in to the new discriminated union functionality for polymorphism.
+     */
+    polymorphismAsDiscriminatedUnions: SetTypesystemOptions extends {
+      future: { polymorphismAsDiscriminatedUnions: true };
+    }
+      ? true
+      : false;
+  };
+};
+
 //////////////////
 // BASETYPE
 //////////////////
@@ -372,6 +391,51 @@ export type $expr_PolyShapeElement<
 };
 
 export type computeObjectShape<
+  Pointers extends ObjectTypePointers,
+  Shape,
+  TypeName extends string = string,
+> = TypesystemOptions["future"]["polymorphismAsDiscriminatedUnions"] extends true
+  ? computeObjectShapeNew<Pointers, Shape, TypeName>
+  : computeObjectShapeLegacy<Pointers, Shape, TypeName>;
+
+type computeObjectShapeLegacy<
+  Pointers extends ObjectTypePointers,
+  Shape,
+  TypeName extends string,
+> = typeutil.flatten<
+  keyof Shape extends never
+    ? { id: string }
+    : typeutil.stripNever<{
+        [k in keyof Shape]: Shape[k] extends $expr_PolyShapeElement<
+          infer PolyType,
+          infer ShapeEl
+        >
+          ? [k] extends [keyof PolyType["__element__"]["__pointers__"]]
+            ? shapeElementToTs<
+                PolyType["__element__"]["__pointers__"][k],
+                ShapeEl,
+                k extends "__type__" ? TypeName : null
+              > | null
+            : never
+          : Shape[k] extends TypeSet
+            ? [k] extends [keyof Pointers]
+              ? Shape[k]["__cardinality__"] extends cardutil.assignable<
+                  Pointers[k]["cardinality"]
+                >
+                ? setToTsType<Shape[k]>
+                : never
+              : setToTsType<Shape[k]>
+            : [k] extends [keyof Pointers]
+              ? shapeElementToTs<
+                  Pointers[k],
+                  Shape[k],
+                  k extends "__type__" ? TypeName : null
+                >
+              : never;
+      }>
+>;
+
+type computeObjectShapeNew<
   Pointers extends ObjectTypePointers,
   Shape,
   TypeName extends string,