fix: case-sensitive routing for sub-router mounting points (silvermin…

…e#17)

When a sub-router was mounted to a given path, the
SubRouterProcessorChain did not respect the router's case-sensitivity
settings. Additionally, sub-routers should NOT inherit their
case-sensitivity settings from their parent router.

src/Router.ts

@@ -70,13 +70,6 @@ export default class Router implements IRouter {
     * code hinting / auto-completion.
     */
    public addSubRouter(path: PathParams, router: Router): this {
-      // Note: this overriding of the case sensitivity of the passed-in router is likely
-      // ineffective for most usecases because the user probably created their router and
-      // added a bunch of routes to it before adding that router to this one. When the
-      // routes are created (technically the `IRequestMatchingProcessorChain` objects, in
-      // particular `RouteMatchingProcessorChain`), the case sensitivity is already set
-      // (inherited from the router that created the chain).
-      router.routerOptions.caseSensitive = this.routerOptions.caseSensitive;
       this._processors.push(new SubRouterProcessorChain(path, router));
       return this;
    }

src/chains/SubRouterProcessorChain.ts

@@ -9,8 +9,7 @@ export class SubRouterProcessorChain implements IRequestMatchingProcessorChain {
    private readonly _router: IRouter;
 
    public constructor(path: PathParams, router: IRouter) {
-      // TODO: case sensitivity settings (strict and end need to remain false here):
-      this._matcher = pathToRegexp(path, [], { sensitive: false, strict: false, end: false });
+      this._matcher = pathToRegexp(path, [], { sensitive: router.routerOptions.caseSensitive, strict: false, end: false });
       this._router = router;
    }
 

tests/integration-tests.test.ts

@@ -46,6 +46,21 @@ describe('integration tests', () => {
       });
    };
 
+   const testOutcome = (method: string, path: string, expectedBody: string): void => {
+      const cb = spy(),
+            evt = makeRequestEvent(path, apiGatewayRequest(), method);
+
+      app.run(evt, handlerContext(), cb);
+
+      assert.calledOnce(cb);
+      assert.calledWithExactly(cb, undefined, {
+         statusCode: 200,
+         body: expectedBody,
+         isBase64Encoded: false,
+         multiValueHeaders: { 'Content-Type': [ 'text/html' ] },
+      });
+   };
+
    describe('very simple smoke test that hits a variety of touch points', () => {
       const test = (evt: RequestEvent): SinonSpy => {
          const cb = spy();
@@ -227,6 +242,74 @@ describe('integration tests', () => {
          testWithLastResortHandler(200, '200 OK', [ 'Content-Type-HTML' ], 'will match');
       });
 
+      it('matches the mounting point path case-insensitively for sub-routes when disabled', () => {
+         // Disable case-sensitive routing
+         const router = new Router({ caseSensitive: false });
+
+         let handler = spy((_req: Request, _resp: Response, next: NextCallback) => { next(); });
+
+         // Case sensitive routing should be *off* for the sub-router, but we turn
+         // case-sensitive routing *on* for the parent router (app) so that we know that
+         // the case-sensitivity settings for the mounting point path are coming from the
+         // sub-router and not the parent router.
+         expect(app.routerOptions.caseSensitive).to.eql(false);
+         app.enable('case sensitive routing');
+         expect(app.routerOptions.caseSensitive).to.eql(true);
+
+         // `/hello/world` is case-insensitive
+         app.addSubRouter('/hello', router);
+         router.get('/world', handler);
+
+         // Return a response
+         app.use((_req: Request, resp: Response) => { resp.send('Hello world'); });
+
+         // Test that the mounting point (`/hello`) is NOT case-sensitive
+         testOutcome('GET', '/hello/world', 'Hello world');
+         assert.calledOnce(handler);
+         handler.resetHistory();
+
+         testOutcome('GET', '/Hello/world', 'Hello world');
+         assert.calledOnce(handler);
+         handler.resetHistory();
+
+         testOutcome('GET', '/HELLO/world', 'Hello world');
+         assert.calledOnce(handler);
+      });
+
+      it('matches the mounting point path case-sensitively for sub-routes when enabled', () => {
+         // Enable case-sensitive routing
+         const router = new Router({ caseSensitive: true });
+
+         let handler;
+
+         // Case sensitive routing should be *on* for the sub-router, but we leave
+         // case-sensitive routing *off* for the parent router (app) so that we know that
+         // the case-sensitivity settings for the mounting point path are coming from the
+         // sub-router and not the parent router.
+         expect(app.routerOptions.caseSensitive).to.eql(false);
+
+         handler = spy((_req: Request, _resp: Response, next: NextCallback) => { next(); });
+
+         // `/Hello/world` is case-sensitive
+         app.addSubRouter('/hello', router);
+         router.get('/world', handler);
+
+         // Return a response
+         app.use((_req: Request, resp: Response) => { resp.send('Hello world'); });
+
+         // Test case-sensitivity in the mounting point (`/hello`)
+         testOutcome('GET', '/HELLO/world', 'Hello world');
+         assert.notCalled(handler);
+         handler.resetHistory();
+
+         testOutcome('GET', '/Hello/world', 'Hello world');
+         assert.notCalled(handler);
+         handler.resetHistory();
+
+         testOutcome('GET', '/hello/world', 'Hello world');
+         assert.calledOnce(handler);
+      });
+
    });
 
    describe('other HTTP methods', () => {
@@ -332,21 +415,6 @@ describe('integration tests', () => {
 
    });
 
-   const testOutcome = (method: string, path: string, expectedBody: string): void => {
-      const cb = spy(),
-            evt = makeRequestEvent(path, apiGatewayRequest(), method);
-
-      app.run(evt, handlerContext(), cb);
-
-      assert.calledOnce(cb);
-      assert.calledWithExactly(cb, undefined, {
-         statusCode: 200,
-         body: expectedBody,
-         isBase64Encoded: false,
-         multiValueHeaders: { 'Content-Type': [ 'text/html' ] },
-      });
-   };
-
    describe('sub-routing', () => {
 
       it('works when we have added a subrouter and subsubrouter to the main app', () => {