fix: always expose referred DefinitionType to avoid issues with recursive intersections of unions

.vscode/settings.json

@@ -12,5 +12,6 @@
   "editor.formatOnSave": true,
   "editor.codeActionsOnSave": {
     "source.fixAll.eslint": true
-  }
+  },
+  "jest.autoRun": "off"
 }

package.json

@@ -88,7 +88,7 @@
     "test:coverage": "yarn jest test/ --collectCoverage=true",
     "test:update": "cross-env UPDATE_SCHEMA=true yarn test:fast",
     "debug": "node -r ts-node/register --inspect-brk ts-json-schema-generator.ts",
-    "run": "ts-node ts-json-schema-generator.ts",
+    "run": "ts-node-transpile-only ts-json-schema-generator.ts",
     "release": "yarn build && auto shipit"
   }
 }

src/TypeFormatter/ReferenceTypeFormatter.ts

@@ -16,8 +16,13 @@ export class ReferenceTypeFormatter implements SubTypeFormatter {
         return { $ref: `#/definitions/${this.encodeRefs ? encodeURIComponent(ref) : ref}` };
     }
     public getChildren(type: ReferenceType): BaseType[] {
-        if (type.getType() instanceof DefinitionType) {
-            return [];
+        const referredType = type.getType();
+        if (referredType instanceof DefinitionType) {
+            // We probably already have the definitions for the children created so we could return `[]`.
+            // There are cases where we may not have (in particular intersections of unions with recursion).
+            // To make sure we create the necessary definitions, we return the children of the referred type here.
+            // Because we cache definitions, this should not incur any performance impact.
+            return this.childTypeFormatter.getChildren(referredType);
         }
 
         // this means that the referred interface is private

test/valid-data-type.test.ts

@@ -43,6 +43,10 @@ describe("valid-data-type", () => {
         "type-intersection-recursive-interface",
         assertValidSchema("type-intersection-recursive-interface", "Intersection")
     );
+    it(
+        "type-intersection-union-recursive-interface",
+        assertValidSchema("type-intersection-union-recursive-interface", "Intersection")
+    );
     it("type-intersection-union", assertValidSchema("type-intersection-union", "MyObject"));
     it("type-intersection-union-enum", assertValidSchema("type-intersection-union-enum", "MyObject"));
     it("type-intersection-union-primitive", assertValidSchema("type-intersection-union", "MyObject"));

test/valid-data/type-intersection-union-recursive-interface/main.ts

@@ -0,0 +1,15 @@
+export interface Container {
+    child: Union;
+}
+
+export interface Dummy {
+    x: number;
+}
+
+export interface Silly {
+    y: number;
+}
+
+export type Union = Container | Silly;
+
+export type Intersection = Union & Dummy;

test/valid-data/type-intersection-union-recursive-interface/schema.json

@@ -0,0 +1,76 @@
+{
+    "$ref": "#/definitions/Intersection",
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "definitions": {
+      "Container": {
+        "additionalProperties": false,
+        "properties": {
+          "child": {
+            "$ref": "#/definitions/Union"
+          }
+        },
+        "required": [
+          "child"
+        ],
+        "type": "object"
+      },
+      "Intersection": {
+        "anyOf": [
+          {
+            "additionalProperties": false,
+            "properties": {
+              "child": {
+                "$ref": "#/definitions/Union"
+              },
+              "x": {
+                "type": "number"
+              }
+            },
+            "required": [
+              "child",
+              "x"
+            ],
+            "type": "object"
+          },
+          {
+            "additionalProperties": false,
+            "properties": {
+              "x": {
+                "type": "number"
+              },
+              "y": {
+                "type": "number"
+              }
+            },
+            "required": [
+              "x",
+              "y"
+            ],
+            "type": "object"
+          }
+        ]
+      },
+      "Silly": {
+        "additionalProperties": false,
+        "properties": {
+          "y": {
+            "type": "number"
+          }
+        },
+        "required": [
+          "y"
+        ],
+        "type": "object"
+      },
+      "Union": {
+        "anyOf": [
+          {
+            "$ref": "#/definitions/Container"
+          },
+          {
+            "$ref": "#/definitions/Silly"
+          }
+        ]
+      }
+    }
+  }