Keep drop count (#18)

* Add keep/drop count to rendered expression output.

* Fix codacy linting issue.

Author: tom-wolfe

karma.conf.js

@@ -23,8 +23,8 @@ module.exports = function (config) {
     ],
     customLaunchers: {
       chromeDebugging: {
-        base: 'Chrome',
-        flags: [ '--remote-debugging-port=9333' ]
+        base: "Chrome",
+        flags: [ "--remote-debugging-port=9333" ]
       },
       chromeTravisCi: {
         base: "Chrome",

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "dice-typescript",
-  "version": "1.5.0",
+  "version": "1.6.0",
   "description": "A TypeScript library for parsing dice rolling expressions, most commonly used in tabletop RPGs.",
   "main": "./dist/index.js",
   "scripts": {

package.json

@@ -29,5 +29,19 @@ describe('DiceGenerator', () => {
       const generator = new Generator.DiceGenerator();
       expect(generator.generate(exp)).toBe('2d6dh');
     });
+    it('generates a drop with modifier (3d6dh2).', () => {
+      const exp = Ast.Factory.create(Ast.NodeType.Drop)
+        .setAttribute('type', 'highest');
+
+      const dice = Ast.Factory.create(Ast.NodeType.Dice);
+      dice.addChild(Ast.Factory.create(Ast.NodeType.Number).setAttribute('value', 3));
+      dice.addChild(Ast.Factory.create(Ast.NodeType.DiceSides).setAttribute('value', 6));
+
+      exp.addChild(dice);
+      exp.addChild(Ast.Factory.create(Ast.NodeType.Number).setAttribute('value', 2));
+
+      const generator = new Generator.DiceGenerator();
+      expect(generator.generate(exp)).toBe('3d6dh2');
+    });
   });
 });

spec/generator/dice-generator.generate.drop.spec.ts

@@ -29,5 +29,19 @@ describe('DiceGenerator', () => {
       const generator = new Generator.DiceGenerator();
       expect(generator.generate(exp)).toBe('2d6kl');
     });
+    it('generates a keep with modifier (3d6kl2).', () => {
+      const exp = Ast.Factory.create(Ast.NodeType.Keep)
+        .setAttribute('type', 'lowest');
+
+      const dice = Ast.Factory.create(Ast.NodeType.Dice);
+      dice.addChild(Ast.Factory.create(Ast.NodeType.Number).setAttribute('value', 3));
+      dice.addChild(Ast.Factory.create(Ast.NodeType.DiceSides).setAttribute('value', 6));
+
+      exp.addChild(dice);
+      exp.addChild(Ast.Factory.create(Ast.NodeType.Number).setAttribute('value', 2));
+
+      const generator = new Generator.DiceGenerator();
+      expect(generator.generate(exp)).toBe('3d6kl2');
+    });
   });
 });

spec/generator/dice-generator.generate.keep.spec.ts

@@ -24,5 +24,26 @@ describe('DiceInterpreter', () => {
       expect(res.renderedExpression).toBe('[1, 7, 4, 5] + 5', 'Expression rendered incorrectly');
       expect(res.total).toBe(22, 'Total counted incorrectly');
     });
+    it('interprets a simple dice expression (4d6kh3).', () => {
+      const exp = Ast.Factory.create(Ast.NodeType.Keep)
+        .setAttribute('type', 'highest');
+
+      const dice = Ast.Factory.create(Ast.NodeType.Dice);
+      dice.addChild(Ast.Factory.create(Ast.NodeType.Number).setAttribute('value', 4));
+      dice.addChild(Ast.Factory.create(Ast.NodeType.Number).setAttribute('value', 6));
+
+      exp.addChild(dice);
+      exp.addChild(Ast.Factory.create(Ast.NodeType.Number).setAttribute('value', 3));
+
+      const mockList = new MockListRandomProvider();
+      mockList.numbers.push(6, 1, 4, 3);
+
+      const interpreter = new Interpreter.DiceInterpreter(null, mockList);
+      const res = interpreter.interpret(exp);
+
+      expect(res.errors.length).toBe(0, 'Unexpected errors found.');
+      expect(res.renderedExpression).toBe('[6, 1, 4, 3]kh3', 'Expression rendered incorrectly');
+      expect(res.total).toBe(13, 'Total counted incorrectly');
+    });
   });
 });

spec/interpreter/dice-interpreter.interpret.simple.ts

@@ -134,18 +134,22 @@ export class DiceGenerator implements Generator<string> {
 
   generateKeep(expression: Ast.ExpressionNode): string {
     this.expectChildCount(expression, 1);
-    let keep = 'k';
-    if (expression.getAttribute('type') === 'highest') { keep += 'h'; }
-    if (expression.getAttribute('type') === 'lowest') { keep += 'l'; }
-    return this.generate(expression.getChild(0)) + keep;
+    let exp = 'k';
+    if (expression.getAttribute('type') === 'highest') { exp += 'h'; }
+    if (expression.getAttribute('type') === 'lowest') { exp += 'l'; }
+
+    if (expression.getChildCount() > 1) { exp += this.generate(expression.getChild(1)); }
+    return this.generate(expression.getChild(0)) + exp;
   }
 
   generateDrop(expression: Ast.ExpressionNode): string {
     this.expectChildCount(expression, 1);
-    let drop = 'd';
-    if (expression.getAttribute('type') === 'highest') { drop += 'h'; }
-    if (expression.getAttribute('type') === 'lowest') { drop += 'l'; }
-    return this.generate(expression.getChild(0)) + drop;
+    let exp = 'd';
+    if (expression.getAttribute('type') === 'highest') { exp += 'h'; }
+    if (expression.getAttribute('type') === 'lowest') { exp += 'l'; }
+
+    if (expression.getChildCount() > 1) { exp += this.generate(expression.getChild(1)); }
+    return this.generate(expression.getChild(0)) + exp;
   }
 
   generateCritical(expression: Ast.ExpressionNode): string {