Improve NestJS sources and dependency injection

javascript/ql/lib/semmle/javascript/frameworks/Nest.qll

@@ -447,6 +447,61 @@ module NestJS {
     }
   }
 
+  /**
+   * A NestJS Middleware Class
+   */
+  private class NestMiddlewareClass extends DataFlow::ClassNode {
+    NestMiddlewareClass() {
+      exists(ClassDefinition cls |
+        this = cls.flow() and
+        cls.getASuperInterface().hasUnderlyingType("@nestjs/common", "NestMiddleware")
+      )
+    }
+
+    DataFlow::FunctionNode getUseFunction() { result = this.getInstanceMethod("use") }
+  }
+
+  /**
+   * A NestJS Middleware Class route handler (the `use` method)
+   */
+  private class MiddlewareRouteHandler extends Http::RouteHandler, DataFlow::FunctionNode {
+    MiddlewareRouteHandler() { this = any(NestMiddlewareClass m).getUseFunction() }
+
+    override Http::HeaderDefinition getAResponseHeader(string name) { none() }
+
+    /**
+     * Gets the request object used by this route
+     */
+    DataFlow::ParameterNode getRequest() { result = this.getParameter(0) }
+
+    /**
+     * Gets the response object used by this route
+     */
+    DataFlow::ParameterNode getResponse() { result = this.getParameter(1) }
+  }
+
+  /**
+   * A source of `express` request objects for NestJS middlewares
+   */
+  private class MiddlewareRequestSource extends Express::RequestSource {
+    MiddlewareRouteHandler middlewareRouteHandler;
+
+    MiddlewareRequestSource() { this = middlewareRouteHandler.getRequest() }
+
+    override Http::RouteHandler getRouteHandler() { result = middlewareRouteHandler }
+  }
+
+  /**
+   * A source of `express` response objects for NestJS middlewares
+   */
+  private class MiddlewareResponseSource extends Express::ResponseSource {
+    MiddlewareRouteHandler middlewareRouteHandler;
+
+    MiddlewareResponseSource() { this = middlewareRouteHandler.getResponse() }
+
+    override Http::RouteHandler getRouteHandler() { result = middlewareRouteHandler }
+  }
+
   /**
    * A value passed in the `providers` array in:
    * ```js
@@ -455,21 +510,53 @@ module NestJS {
    * ```
    */
   private DataFlow::Node providerTuple() {
-    result =
-      DataFlow::moduleImport("@nestjs/common")
-          .getAPropertyRead("Module")
-          .getACall()
-          .getOptionArgument(0, "providers")
-          .getALocalSource()
-          .(DataFlow::ArrayCreationNode)
-          .getAnElement()
+    exists(DataFlow::CallNode moduleCall |
+      moduleCall = DataFlow::moduleImport("@nestjs/common").getAPropertyRead("Module").getACall() and
+      result = providerTupleAux(moduleCall.getArgument(0).getALocalSource())
+    )
+  }
+
+  private DataFlow::Node providerTupleAux(DataFlow::ObjectLiteralNode o) {
+    (
+      result =
+        o.getAPropertyWrite("providers")
+            .getRhs()
+            .getALocalSource()
+            .(DataFlow::ArrayCreationNode)
+            .getAnElement()
+      or
+      result =
+        providerTupleAux(o.getAPropertyWrite("imports")
+              .getRhs()
+              .getALocalSource()
+              .(DataFlow::ArrayCreationNode)
+              .getAnElement()
+              .(DataFlow::CallNode)
+              .getCalleeNode()
+              .getAFunctionValue()
+              .getFunction()
+              .getAReturnedExpr()
+              .flow())
+    )
+  }
+
+  private DataFlow::Node getConcreteClassFromProviderTuple(DataFlow::SourceNode tuple) {
+    result = tuple.getAPropertyWrite("useClass").getRhs()
+    or
+    exists(DataFlow::FunctionNode f |
+      f = tuple.getAPropertyWrite("useFactory").getRhs().getAFunctionValue() and
+      result.getAstNode() = f.getFunction().getAReturnedExpr().getType().(ClassType).getClass()
+    )
+    or
+    result.getAstNode() =
+      tuple.getAPropertyWrite("useValue").getRhs().asExpr().getType().(ClassType).getClass()
   }
 
   private predicate providerPair(DataFlow::Node interface, DataFlow::Node concreteClass) {
     exists(DataFlow::SourceNode tuple |
       tuple = providerTuple().getALocalSource() and
       interface = tuple.getAPropertyWrite("provide").getRhs() and
-      concreteClass = tuple.getAPropertyWrite("useClass").getRhs()
+      concreteClass = getConcreteClassFromProviderTuple(tuple)
     )
   }
 

javascript/ql/test/library-tests/frameworks/Nest/global/app.module.ts

@@ -1,12 +1,27 @@
 import { Module } from '@nestjs/common';
 import { Controller } from './validation';
-import { Foo } from './foo.interface';
-import { FooImpl } from './foo.impl';
+import { Imports } from './imports';
+import { Foo, Foo2, Foo3 } from './foo.interface';
+import { FooImpl, Foo2Impl, Foo3Impl } from './foo.impl';
+
+const foo3 = new Foo3Impl()
 
 @Module({
-    controllers: [Controller],
-    providers: [{
-        provide: Foo, useClass: FooImpl
-    }],
+  controllers: [Controller],
+  imports: [Imports.forRoot()],
+  providers: [
+    {
+      provide: Foo,
+      useClass: FooImpl
+    },
+    {
+      provide: Foo2,
+      useFactory: () => new Foo2Impl()
+    },
+    {
+      provide: Foo3,
+      useValue: foo3
+    }
+  ],
 })
 export class AppModule { }

javascript/ql/test/library-tests/frameworks/Nest/global/foo.impl.ts

@@ -1,7 +1,25 @@
-import { Foo } from "./foo.interface";
+import { Foo, Foo2, Foo3, Foo4 } from "./foo.interface";
 
 export class FooImpl extends Foo {
     fooMethod(x: string) {
         sink(x); // $ hasValueFlow=x
     }
 }
+
+export class Foo2Impl extends Foo2 {
+    fooMethod(x: string) {
+        sink(x); // $ hasValueFlow=x
+    }
+}
+
+export class Foo3Impl extends Foo3 {
+    fooMethod(x: string) {
+        sink(x); // $ hasValueFlow=x
+    }
+}
+
+export class Foo4Impl extends Foo4 {
+    fooMethod(x: string) {
+        sink(x); // $ hasValueFlow=x
+    }
+}

javascript/ql/test/library-tests/frameworks/Nest/global/foo.interface.ts

@@ -1,3 +1,15 @@
 export abstract class Foo {
     abstract fooMethod(x: string): void;
 }
+
+export abstract class Foo2 {
+    abstract fooMethod(x: string): void;
+}
+
+export abstract class Foo3 {
+    abstract fooMethod(x: string): void;
+}
+
+export abstract class Foo4 {
+    abstract fooMethod(x: string): void;
+}

javascript/ql/test/library-tests/frameworks/Nest/global/imports.ts

@@ -0,0 +1,16 @@
+import { DynamicModule } from '@nestjs/common';
+import { Foo4Impl } from './foo.impl';
+import { Foo4 } from './foo.interface';
+
+export class Imports {
+  static forRoot(): DynamicModule {
+    return {
+      providers: [
+        {
+          provide: Foo4,
+          useClass: Foo4Impl,
+        },
+      ],
+    };
+  }
+}

javascript/ql/test/library-tests/frameworks/Nest/global/validation.ts

@@ -1,10 +1,10 @@
 import { Get, Query } from '@nestjs/common';
 import { IsIn } from 'class-validator';
-import { Foo } from './foo.interface';
+import { Foo, Foo2, Foo3, Foo4 } from './foo.interface';
 
 export class Controller {
   constructor(
-    private readonly foo: Foo
+    private readonly foo: Foo, private readonly foo2: Foo2, private readonly foo3: Foo3, private readonly foo4: Foo4
   ) { }
 
   @Get()
@@ -16,6 +16,9 @@ export class Controller {
   @Get()
   route2(@Query('x') x: string) {
     this.foo.fooMethod(x);
+    this.foo2.fooMethod(x);
+    this.foo3.fooMethod(x);
+    this.foo4.fooMethod(x);
   }
 }
 

javascript/ql/test/library-tests/frameworks/Nest/local/middleware.ts

@@ -0,0 +1,12 @@
+import { Injectable, NestMiddleware } from '@nestjs/common';
+import { Response, NextFunction } from 'express';
+import { CustomRequest } from '@randomPackage/request';
+
+@Injectable()
+export class LoggerMiddleware implements NestMiddleware {
+  // The request can be a custom type that extends the express Request
+  use(req: CustomRequest, res: Response, next: NextFunction) {
+    console.log(req.query.abc);
+    next();
+  }
+}

javascript/ql/test/library-tests/frameworks/Nest/test.expected

@@ -1,7 +1,7 @@
 testFailures
 routeHandler
 | global/validation.ts:11:3:14:3 | route1( ...  OK\\n  } |
-| global/validation.ts:17:3:19:3 | route2( ... x);\\n  } |
+| global/validation.ts:17:3:22:3 | route2( ... x);\\n  } |
 | local/customDecorator.ts:18:3:20:3 | sneaky( ...  OK\\n  } |
 | local/customDecorator.ts:23:3:25:3 | safe(@S ...  OK\\n  } |
 | local/customPipe.ts:20:5:22:5 | sanitiz ... K\\n    } |
@@ -10,6 +10,7 @@ routeHandler
 | local/customPipe.ts:36:5:38:5 | propaga ... K\\n    } |
 | local/customPipe.ts:41:5:43:5 | propaga ... K\\n    } |
 | local/customPipe.ts:47:5:49:5 | propaga ... K\\n    } |
+| local/middleware.ts:8:3:11:3 | use(req ... ();\\n  } |
 | local/routes.ts:6:3:8:3 | getFoo( ... o';\\n  } |
 | local/routes.ts:11:3:13:3 | postFoo ... o';\\n  } |
 | local/routes.ts:16:3:18:3 | getRoot ... o';\\n  } |
@@ -29,9 +30,11 @@ routeHandler
 | local/validation.ts:42:3:45:3 | route6( ...  OK\\n  } |
 requestSource
 | local/customDecorator.ts:5:21:5:51 | ctx.swi ... quest() |
+| local/middleware.ts:8:7:8:9 | req |
 | local/routes.ts:30:12:30:14 | req |
 | local/routes.ts:61:23:61:25 | req |
 responseSource
+| local/middleware.ts:8:27:8:29 | res |
 | local/routes.ts:61:35:61:37 | res |
 | local/routes.ts:62:5:62:25 | res.sen ... uery.x) |
 requestInputAccess
@@ -44,6 +47,7 @@ requestInputAccess
 | parameter | local/customDecorator.ts:6:12:6:41 | request ... ryParam |
 | parameter | local/customPipe.ts:5:15:5:19 | value |
 | parameter | local/customPipe.ts:13:15:13:19 | value |
+| parameter | local/middleware.ts:9:17:9:29 | req.query.abc |
 | parameter | local/routes.ts:27:17:27:17 | x |
 | parameter | local/routes.ts:28:14:28:21 | queryObj |
 | parameter | local/routes.ts:29:20:29:23 | name |