[DO NOT MERGE] Reproduce 5436

packages/import/tests/schema/fixtures/multiple-levels/shared.graphql

@@ -0,0 +1,21 @@
+interface A {
+  field: String
+}
+
+type B {
+  field: C
+}
+
+type C {
+  field: D
+}
+
+union D = E | F
+
+type E {
+  e: String
+}
+
+type F implements A {
+  field: String
+}

packages/import/tests/schema/fixtures/unions/c.graphql

@@ -1,11 +1,21 @@
+interface I {
+  c4: ID
+}
+
 type C1 {
   c1: ID
 }
 
 type C2 {
-  c2: ID
+  c2: C3
+}
+
+union C3 = C4 | C5
+
+type C4 implements I {
+  c4: ID
 }
 
-type C3 {
-  c3: ID
+type C5 {
+  C5: ID
 }

packages/import/tests/schema/import-schema.spec.ts

@@ -953,6 +953,38 @@ describe('importSchema', () => {
     expect(importSchema('fixtures/multiple-levels/level1.graphql')).toBeSimilarGqlDoc(expectedSDL);
   });
 
+  test('imports with union dependencies', () => {
+    const expectedSDL = /* GraphQL */ `
+      type A {
+        b: B
+      }
+      union B = C1 | C2
+
+      interface I {
+        c4: ID
+      }
+
+      type C1 {
+        c1: ID
+      }
+
+      type C2 {
+        c2: C3
+      }
+
+      union C3 = C4 | C5
+
+      type C4 implements I {
+        c4: ID
+      }
+
+      type C5 {
+        C5: ID
+      }
+    `;
+    expect(importSchema('fixtures/unions/a.graphql')).toBeSimilarGqlDoc(expectedSDL);
+  });
+
   test('imports dependencies at least 3 levels deep with transitive dependencies while using master schemata', () => {
     const expectedSDL = /* GraphQL */ `
       type Account {