shift-interpreter/test/evaluation/loops.test.ts

Shift-interpreter is an experimental JavaScript meta-interpreter useful for reverse engineering and analysis. One notable difference from other projects is that shift-interpreter retains state over an entire script but can be fed expressions and statement

import { assertResult, compare } from '../util';

describe('Loops', () => {
  describe('For Loops', () => {
    it('should evaluate basic for loops', () => {
      assertResult(compare('let b = 0; for (let a = 1; a <= 2; a++) {b = b + a} b;'));
    });
    it('should support break statements', () => {
      assertResult(compare('let b = 0; for (let a = 1; a <= 2; a++) {b = b + a; break} b;'));
    });
    it('should support nested break statements', () => {
      assertResult(
        compare('let b = 0; for (let a = 1; a <= 2; a++) {for (let i = 1; i < 10; i++) {break; b++;}; b = b + a;} b;'),
      );
    });
    it('should support continue statements', () => {
      assertResult(compare('let b = 0; for (let a = 1; a <= 2; a++) {b = b + a; continue; b += 2} b;'));
    });
    it('should support nested continue statements', () => {
      assertResult(
        compare(
          'let b = 0; for (let a = 1; a <= 2; a++) {for (let i = 1; i < 10; i++) {b++; continue; b++;}; b = b + a;} b;',
        ),
      );
    });
  });
  it('should support for...in statements', () => {
    assertResult(compare(`let a = {a:1,b:2},c = 0; for (let b in a) { c+=a[b]; } c;`));
    assertResult(compare(`let a = {a:1,b:2},c = 0,b; for (b in a) { c+=a[b]; } c;`));
  });
  it('should support for...of statements', () => {
    assertResult(compare(`let a = [1,2],c = 0; for (let b of a) { c+=b; } c;`));
  });
  it('should support while statements', () => {
    assertResult(compare('let a = 0; while(a < 10) {a++} a;'));
  });
  it('should support do-while statements', () => {
    assertResult(compare('let a = 0; do{a++}while(a < 10) a;'));
  });
});