Support interface inheritance

lib/extractors.js

@@ -20,7 +20,23 @@ const extractors = {
     },
 
     * InterfaceDeclaration(node) {
-        const schema = yield node.body;
+        let schema = yield node.body;
+
+        if (node.extends.length > 0) {
+            const schemas = [];
+
+            for (const extend of node.extends) {
+                const name = yield extend;
+                const schema = yield query(name);
+
+                schemas.push(schema);
+            }
+
+            schemas.push(schema);
+
+            schema = mergeSchemas(schemas);
+        }
+
         schema.name = yield node.id;
         schema.namespace = yield namespace();
 
@@ -199,6 +215,10 @@ const extractors = {
         yield exit();
     },
 
+    * InterfaceExtends(node) {
+        return yield node.id;
+    },
+
     * Identifier(node) {
         return node.name;
     },

tests/inherit.js

@@ -1,40 +0,0 @@
-class A {
-    a: number;
-}
-
-class B extends A {
-    b: string;
-}
-
-class C extends B {
-    c: boolean;
-}
-
-// ###
-[
-    {
-        type: 'record',
-        name: 'A',
-        namespace: 'inherit',
-        fields: [{name: 'a', type: 'double'}],
-    },
-    {
-        type: 'record',
-        name: 'B',
-        namespace: 'inherit',
-        fields: [
-            {name: 'a', type: 'double'},
-            {name: 'b', type: 'string'},
-        ],
-    },
-    {
-        type: 'record',
-        name: 'C',
-        namespace: 'inherit',
-        fields: [
-            {name: 'a', type: 'double'},
-            {name: 'b', type: 'string'},
-            {name: 'c', type: 'boolean'},
-        ],
-    },
-]

tests/inheritance.js

@@ -0,0 +1,77 @@
+class A {
+    a: number;
+}
+
+class B extends A {
+    b: string;
+}
+
+class C extends B {
+    c: boolean;
+}
+
+interface X {
+    x: number;
+}
+
+interface Y extends X {
+    y: string;
+}
+
+interface Z extends Y {
+    z: boolean;
+}
+
+// ###
+[
+    {
+        type: 'record',
+        name: 'A',
+        namespace: 'inheritance',
+        fields: [{name: 'a', type: 'double'}],
+    },
+    {
+        type: 'record',
+        name: 'B',
+        namespace: 'inheritance',
+        fields: [
+            {name: 'a', type: 'double'},
+            {name: 'b', type: 'string'},
+        ],
+    },
+    {
+        type: 'record',
+        name: 'C',
+        namespace: 'inheritance',
+        fields: [
+            {name: 'a', type: 'double'},
+            {name: 'b', type: 'string'},
+            {name: 'c', type: 'boolean'},
+        ],
+    },
+    {
+        type: 'record',
+        name: 'X',
+        namespace: 'inheritance',
+        fields: [{name: 'x', type: 'double'}],
+    },
+    {
+        type: 'record',
+        name: 'Y',
+        namespace: 'inheritance',
+        fields: [
+            {name: 'x', type: 'double'},
+            {name: 'y', type: 'string'},
+        ],
+    },
+    {
+        type: 'record',
+        name: 'Z',
+        namespace: 'inheritance',
+        fields: [
+            {name: 'x', type: 'double'},
+            {name: 'y', type: 'string'},
+            {name: 'z', type: 'boolean'},
+        ],
+    },
+]