Compiler bug fixes (#52)

* Fix bug

* Fix instance method with this keyword

* Fix linting

* Throw error when method resolution fails

* Abstract out peggy functions to avoid duplication

* Fix linting

* Resolve TODO markers

* Fix linting

* Fix boolean expression

* Fix linting

---------

Co-authored-by: Aprup Kale <[email protected]>

Author: 1001mei

src/compiler/__tests__/__utils__/test-utils.ts

@@ -3,6 +3,7 @@ import { compile } from "../../index";
 import { BinaryWriter } from "../../binary-writer";
 import { AST } from "../../../ast/types/packages-and-modules";
 import { javaPegGrammar } from "../../grammar"
+import { peggyFunctions } from '../../peggy-functions'
 import { execSync } from "child_process";
 
 import * as peggy from "peggy";
@@ -16,7 +17,7 @@ export type testCase = {
 
 const debug = false;
 const pathToTestDir = "./src/compiler/__tests__/";
-const parser = peggy.generate(javaPegGrammar, {
+const parser = peggy.generate(peggyFunctions + javaPegGrammar, {
   allowedStartRules: ["CompilationUnit"],
 });
 const binaryWriter = new BinaryWriter();

src/compiler/__tests__/tests/array.test.ts

@@ -181,6 +181,20 @@ const testCases: testCase[] = [
     `,
     expectedLines: ["J", "a", "v", "a"],
   },
+  {
+    comment: "array of string",
+    program: `
+      public class Main {
+        public static void main(String[] args) {
+          String[] sarr = {"asdf", "qwer", "zxcv"};
+          for (int i = 0; i < sarr.length; i++) {
+            System.out.println(sarr[sarr.length - 1 - i]);
+          }
+        }
+      }
+    `,
+    expectedLines: ["zxcv", "qwer", "asdf"],
+  },
   {
     comment: "array of reference type",
     program: `

src/compiler/__tests__/tests/class.test.ts

@@ -144,6 +144,31 @@ const testCases: testCase[] = [
     `,
     expectedLines: ["100", "101", "100"],
   },
+  {
+    comment: "instance method using this keyword",
+    program: `
+      public class Main {
+        public void f() {
+          System.out.println("In f");
+        }
+        public void g() {
+          System.out.println("In g");
+        }
+
+        public void print() {
+          this.f();
+          System.out.println("In print");
+          this.g();
+        }
+
+        public static void main(String[] args) {
+          Main m = new Main();
+          m.print();
+        }
+      }
+    `,
+    expectedLines: ["In f", "In print", "In g"],
+  },
 ];
 
 export const classTest = () => describe("fields and methods of class", () => {

src/compiler/__tests__/tests/ifElse.test.ts

@@ -246,13 +246,31 @@ const testCases: testCase[] = [
           } else {
             System.out.println("Yes3");
           }
+        }
+      }
+    `,
+    expectedLines: ["Yes1", "Yes2", "Yes3"],
+  },
+  {
+    comment: "boolean expression",
+    program: `
+      public class Main {
+        public static void main(String[] args) {
+          boolean b = true;
+          boolean c = !b;
 
           boolean d = !(!(!(b == c)));
           System.out.println(d);
+
+          boolean e = null == null;
+          System.out.println(e);
+
+          Main m = new Main();
+          System.out.println(null == m);
         }
       }
     `,
-    expectedLines: ["Yes1", "Yes2", "Yes3", "true"],
+    expectedLines: ["true", "true", "false"],
   },
   {
     comment: "complex conditional expression",

src/compiler/__tests__/tests/unaryExpression.test.ts

@@ -71,6 +71,75 @@ const testCases: testCase[] = [
     }`,
     expectedLines: ["4", "1", "3", "2", "2", "3", "3"],
   },
+  {
+    comment: "increment/decrement on class fields",
+    program: `
+    public class Main {
+      public static int g;
+      public static int h;
+      public static void main(String[] args) {
+        g = 10;
+        System.out.println(g);
+        g++;
+        System.out.println(g);
+        ++g;
+        System.out.println(g);
+
+        h = 20;
+        System.out.println(h);
+        --h;
+        System.out.println(h);
+        h--;
+        System.out.println(h);
+      }
+    }`,
+    expectedLines: ["10", "11", "12", "20", "19", "18"],
+  },
+  {
+    comment: "increment/decrement on instance fields",
+    program: `
+    public class Main {
+      public int x;
+      public void inc() {
+        this.x++;
+      }
+      public void dec() {
+        this.x--;
+      }
+
+      public static void main(String[] args) {
+        Main m = new Main();
+        System.out.println(m.x);
+        m.inc();
+        m.inc();
+        System.out.println(m.x);
+        m.x = 100;
+        m.dec();
+        System.out.println(m.x);
+      }
+    }`,
+    expectedLines: ["0", "2", "99"],
+  },
+  {
+    comment: "increment/decrement on arrays",
+    program: `
+    public class Main {
+      public static void main(String[] args) {
+        int[] arr = {1, 5, 10, 15, 20};
+        arr[0]++;
+        --arr[1];
+        System.out.println(arr[0]);
+        System.out.println(arr[1]);
+
+        arr[3] = arr[2]++;
+        arr[4] = --arr[2];
+        System.out.println(arr[3]);
+        System.out.println(arr[4]);
+        System.out.println(arr[2]);
+      }
+    }`,
+    expectedLines: ["2", "4", "10", "10", "10"],
+  },
   {
     comment: "unary plus/minus",
     program: `