fixes #56

Author: Umed Khudoiberdiev

src/ContainerInstance.ts

@@ -231,7 +231,7 @@ export class ContainerInstance {
                 return service.id === identifier;
 
             if (service.type && identifier instanceof Function)
-                return service.type === identifier || identifier.prototype instanceof service.type;
+                return service.type === identifier; // todo: not sure why it was here || identifier.prototype instanceof service.type;
 
             return false;
         });

test/github-issues/56/issue-56.spec.ts

@@ -0,0 +1,38 @@
+import "reflect-metadata";
+import {Container} from "../../../src/Container";
+import {Service} from "../../../src/decorators/Service";
+import {expect} from "chai";
+
+describe("github issues > #56 extended class is being overwritten", function() {
+
+    beforeEach(() => Container.reset());
+
+    it("should work properly", function() {
+
+        @Service()
+        class Rule {
+            getRule() {
+                return "very strict rule";
+            }
+        }
+
+        @Service()
+        class Whitelist extends Rule {
+            getWhitelist() {
+                return ["rule1", "rule2"];
+            }
+        }
+
+        const whitelist = Container.get(Whitelist);
+        expect(whitelist.getRule).to.not.be.undefined;
+        expect(whitelist.getWhitelist).to.not.be.undefined;
+        whitelist.getWhitelist().should.be.eql(["rule1", "rule2"]);
+        whitelist.getRule().should.be.equal("very strict rule");
+
+        const rule = Container.get(Rule);
+        expect(rule.getRule).to.not.be.undefined;
+        expect((rule as Whitelist).getWhitelist).to.be.undefined;
+        rule.getRule().should.be.equal("very strict rule");
+    });
+
+});