diff --git a/simulator/package.json b/simulator/package.json
index d6d538b14..cbdc9e86c 100644
--- a/simulator/package.json
+++ b/simulator/package.json
@@ -38,6 +38,8 @@
     "build": "tsc",
     "test": "jest --verbose",
     "test-w": "jest --watchAll --verbose",
+    "test-jack": "npm run test -- -t \"Jack\"",
+    "test-jack-w": "npm run test-w -- -t \"Jack\"",
     "gen": "cd src/languages/grammars && antlr4 -Dlanguage=TypeScript  JackLexer.g4 JackParser.g4 -o ../../jack/generated"
   }
 }
diff --git a/simulator/src/jack/builtins.ts b/simulator/src/jack/builtins.ts
index cbb14dddd..672dc2f2a 100644
--- a/simulator/src/jack/builtins.ts
+++ b/simulator/src/jack/builtins.ts
@@ -8,8 +8,7 @@ interface Range {
 export const intRange = { min: -32768, max: 32767 } as Range;
 const builtInFunctionsToArgCount: Record<string, number> = {
   "Array.dispose": 0,
-  //TODO: what is this?
-  // "Array.init": 0,
+  "Array.init": 0,
   "Array.new": 1,
   "Keyboard.init": 0,
   "Keyboard.keyPressed": 0,
@@ -18,19 +17,18 @@ const builtInFunctionsToArgCount: Record<string, number> = {
   "Keyboard.readLine": 1,
   "Math.abs": 1,
   "Math.divide": 2,
-  //TODO: what is this ?
-  // "Math.init": 0,
+  "Math.init": 0,
   "Math.max": 2,
   "Math.min": 2,
   "Math.multiply": 2,
   "Math.sqrt": 1,
   "Memory.alloc": 1,
   "Memory.deAlloc": 1,
-  // "Memory.init": 0,
+  "Memory.init": 0,
   "Memory.peek": 1,
   "Memory.poke": 2,
   "Output.backSpace": 0,
-  // "Output.init": 0,
+  "Output.init": 0,
   "Output.moveCursor": 2,
   "Output.printChar": 1,
   "Output.printInt": 1,
@@ -41,7 +39,7 @@ const builtInFunctionsToArgCount: Record<string, number> = {
   "Screen.drawLine": 4,
   "Screen.drawPixel": 2,
   "Screen.drawRectangle": 4,
-  // "Screen.init": 0,
+  "Screen.init": 0,
   "Screen.setColor": 1,
   "String.appendChar": 1,
   "String.backSpace": 0,
@@ -49,7 +47,7 @@ const builtInFunctionsToArgCount: Record<string, number> = {
   "String.dispose": 0,
   "String.doubleQuote": 0,
   "String.eraseLastChar": 0,
-  // "String.init": 0,
+  "String.init": 0,
   "String.intValue": 0,
   "String.length": 0,
   "String.new": 1,
diff --git a/simulator/src/jack/compiler.test.ts b/simulator/src/jack/compiler.test.ts
index 1620e4dcb..9be784b70 100644
--- a/simulator/src/jack/compiler.test.ts
+++ b/simulator/src/jack/compiler.test.ts
@@ -3,7 +3,7 @@ import { getTestResourcePath, testResourceDirs } from "./test.helper";
 import path from "path";
 import { ProgramContext } from "./generated/JackParser";
 import { Compiler } from "./compiler";
-describe("Compiler", () => {
+describe("Jack compiler", () => {
   test("static field", () => {
     testCompiler(
       `class A{
diff --git a/simulator/src/jack/listener/binder.listener.test.ts b/simulator/src/jack/listener/binder.listener.test.ts
index 09839d282..6c9769ffc 100644
--- a/simulator/src/jack/listener/binder.listener.test.ts
+++ b/simulator/src/jack/listener/binder.listener.test.ts
@@ -10,7 +10,7 @@ import {
   parseJackText,
 } from "../test.helper";
 
-describe("Binder", () => {
+describe("Jack binder", () => {
   const jestConsole = console;
 
   beforeEach(() => {
diff --git a/simulator/src/jack/listener/validator.listener.test.ts b/simulator/src/jack/listener/validator.listener.test.ts
index ce0ed44f7..33c584360 100644
--- a/simulator/src/jack/listener/validator.listener.test.ts
+++ b/simulator/src/jack/listener/validator.listener.test.ts
@@ -35,7 +35,7 @@ import fs from "fs";
 import { BinderListener } from "./binder.listener";
 import path from "path";
 import { ProgramContext } from "../generated/JackParser";
-describe("ValidatorListener", () => {
+describe("Jack validator listener", () => {
   const jestConsole = console;
   beforeEach(() => {
     global.console = require("console");
@@ -119,7 +119,7 @@ describe("ValidatorListener", () => {
             }`,
       UndeclaredVariableError,
       {
-        Main: genericSymbol(),
+        "Main": genericSymbol(),
         "Main.b": genericSymbol(SubroutineType.Function, 1),
         "Main.a": genericSymbol(SubroutineType.Function, 1),
       },
@@ -468,7 +468,7 @@ describe("ValidatorListener", () => {
             }`,
       IncorrectParamsNumberInSubroutineCallError,
       {
-        Main: genericSymbol(),
+        "Main": genericSymbol(),
         "Main.a": genericSymbol(SubroutineType.Function, 2),
         "Main.b": genericSymbol(SubroutineType.Function, 2),
       },
@@ -494,7 +494,7 @@ describe("ValidatorListener", () => {
             }`,
       undefined,
       {
-        Main: genericSymbol(),
+        "Main": genericSymbol(),
         "Main.new": genericSymbol(SubroutineType.Constructor, 0),
         "Main.a": genericSymbol(SubroutineType.Function, 0),
         "Main.b": genericSymbol(SubroutineType.Method, 0),
@@ -515,7 +515,7 @@ describe("ValidatorListener", () => {
             }`,
       undefined,
       {
-        Main: genericSymbol(),
+        "Main": genericSymbol(),
         "Main.a": genericSymbol(SubroutineType.Method, 0),
         "Main.b": genericSymbol(SubroutineType.Method, 0),
       },
@@ -539,7 +539,7 @@ describe("ValidatorListener", () => {
             }`,
       MethodCalledAsFunctionError,
       {
-        Main: genericSymbol(),
+        "Main": genericSymbol(),
         "Main.b": genericSymbol(SubroutineType.Function, 0),
         "Main.c": genericSymbol(SubroutineType.Method, 0),
       },
@@ -559,7 +559,7 @@ describe("ValidatorListener", () => {
             }`,
       FunctionCalledAsMethodError,
       {
-        Main: genericSymbol(),
+        "Main": genericSymbol(),
         "Main.b": genericSymbol(SubroutineType.Function, 0),
         "Main.c": genericSymbol(SubroutineType.Function, 0),
       },
@@ -575,7 +575,7 @@ describe("ValidatorListener", () => {
             }`,
       IncorrectConstructorReturnType,
       {
-        Main: genericSymbol(),
+        "Main": genericSymbol(),
         D: genericSymbol(),
       },
     );
@@ -593,7 +593,7 @@ describe("ValidatorListener", () => {
             }`,
       UnreachableCodeError,
       {
-        Main: genericSymbol(),
+        "Main": genericSymbol(),
         "Main.new": genericSymbol(SubroutineType.Constructor, 0),
       },
     );
@@ -608,7 +608,7 @@ describe("ValidatorListener", () => {
             }`,
       ConstructorMushReturnThis,
       {
-        Main: genericSymbol(),
+        "Main": genericSymbol(),
         "Main.new": genericSymbol(SubroutineType.Constructor, 0),
       },
     );
@@ -625,7 +625,7 @@ describe("ValidatorListener", () => {
             }`,
       WrongLiteralTypeError,
       {
-        Main: genericSymbol(),
+        "Main": genericSymbol(),
         "Main.a": genericSymbol(SubroutineType.Function, 0),
         String: genericSymbol(),
       },
@@ -643,7 +643,7 @@ describe("ValidatorListener", () => {
             }`,
       WrongLiteralTypeError,
       {
-        Main: genericSymbol(),
+        "Main": genericSymbol(),
         "Main.a": genericSymbol(SubroutineType.Function, 0),
       },
     );
@@ -661,7 +661,7 @@ describe("ValidatorListener", () => {
             }`,
       WrongLiteralTypeError,
       {
-        Main: genericSymbol(),
+        "Main": genericSymbol(),
         "Main.a": genericSymbol(SubroutineType.Function, 0),
       },
     );
@@ -678,7 +678,7 @@ describe("ValidatorListener", () => {
             }`,
       IntLiteralOverflow,
       {
-        Main: genericSymbol(),
+        "Main": genericSymbol(),
         "Main.a": genericSymbol(SubroutineType.Function, 0),
       },
     );
@@ -695,7 +695,7 @@ describe("ValidatorListener", () => {
             }`,
       IntLiteralOverflow,
       {
-        Main: genericSymbol(),
+        "Main": genericSymbol(),
         "Main.a": genericSymbol(SubroutineType.Function, 0),
       },
     );
@@ -712,7 +712,7 @@ describe("ValidatorListener", () => {
             }`,
       FieldCantBeReferencedInFunction,
       {
-        Main: genericSymbol(),
+        "Main": genericSymbol(),
         "Main.a": genericSymbol(SubroutineType.Function, 0),
       },
     );
@@ -729,7 +729,7 @@ describe("ValidatorListener", () => {
             }`,
       undefined,
       {
-        Main: genericSymbol(),
+        "Main": genericSymbol(),
         "Main.a": genericSymbol(SubroutineType.Function, 0),
       },
     );
@@ -746,7 +746,7 @@ describe("ValidatorListener", () => {
             }`,
       ThisCantBeReferencedInFunction,
       {
-        Main: genericSymbol(),
+        "Main": genericSymbol(),
         "Main.a": genericSymbol(SubroutineType.Function, 0),
       },
     );
@@ -794,9 +794,6 @@ function testValidator<T extends { name: string }>(
     new ValidatorListener(globalSymbolTable),
   );
   if (expectedError) {
-    // if (validator.cfgNode) {
-    //     validator.cfgNode.print()
-    // }
     if (validator.errors.length > 1) {
       console.error("Errors", validator.errors);
     }
@@ -806,8 +803,8 @@ function testValidator<T extends { name: string }>(
     } catch (e) {
       throw new Error(
         `Expected error ${expectedError.name} but got '` +
-          validator.errors.join(",") +
-          "'",
+        validator.errors.join(",") +
+        "'",
       );
     }
   } else {
@@ -816,13 +813,9 @@ function testValidator<T extends { name: string }>(
         "Didn't expect any errors but got " + validator.errors.join("\n"),
       );
   }
-  // if (expectedLocalSymbolTable != undefined) {
-  //     expect(validator.localSymbolTable).toEqual(expectedLocalSymbolTable)
-  // }
 }
 
-//TODO: add validation for assgining from void function call
-//TODO: Add rule to forbid var use before assignment
+
 /**
  * TODO:
  *  Ideas for improvement -
@@ -831,4 +824,6 @@ function testValidator<T extends { name: string }>(
  * - Expected subroutine name in call
  * - a numeric value is illegal here when using non numeric vars
  * - validate function call - when using literal in call validate the type
+ *  add validation for assigning from void function call
+ *  add rule to forbid var use before assignment
  */
diff --git a/simulator/src/jack/parser.test.ts b/simulator/src/jack/parser.test.ts
index 73e227899..3de130d1c 100644
--- a/simulator/src/jack/parser.test.ts
+++ b/simulator/src/jack/parser.test.ts
@@ -10,7 +10,7 @@ import {
 } from "./test.helper";
 import { BinderListener } from "./listener/binder.listener";
 
-describe("Parser", () => {
+describe("Jack parser", () => {
   const jestConsole = console;
   beforeEach(() => {
     global.console = require("console");
diff --git a/simulator/src/jack/symbol.table.test.ts b/simulator/src/jack/symbol.table.test.ts
index 97ca4b804..021c21c58 100644
--- a/simulator/src/jack/symbol.table.test.ts
+++ b/simulator/src/jack/symbol.table.test.ts
@@ -5,7 +5,7 @@ import {
   SubroutineScope,
 } from "./symbol";
 
-describe("LocalSymbolTable", () => {
+describe("Jack local symbol table", () => {
   const jestConsole = console;
 
   beforeEach(() => {