allow to throw multiple dice (#120)

boardgameio · Feb 23, 2018 · ebe7758 · ebe7758
1 parent 8c88b70
commit ebe7758
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Showing 2 changed files with 47 additions and 10 deletions.
diff --git a/src/core/random.js b/src/core/random.js
@@ -68,8 +68,14 @@ const SpotValue = {
 const predefined = {};
 for (const key in SpotValue) {
   const spotvalue = SpotValue[key];
-  predefined[key] = () => {
-    return Math.floor(random() * spotvalue) + 1;
+  predefined[key] = diceCount => {
+    if (diceCount === undefined) {
+      return Math.floor(random() * spotvalue) + 1;
+    } else {
+      return [...Array(diceCount).keys()].map(
+        () => Math.floor(random() * spotvalue) + 1
+      );
+    }
   };
 }
 
@@ -91,27 +97,39 @@ export function GenSeed() {
 export const Random = {
   /**
    * Similar to Die below, but with fixed spot values.
+   * Supports passing a diceCount
+   *    if not defined, defaults to 1 and returns the value directly.
+   *    if defined, returns an array containing the random dice values.
    *
-   * D4: () => value
-   * D6: () => value
-   * D8: () => value
-   * D10: () => value
-   * D12: () => value
-   * D20: () => value
+   * D4: (diceCount) => value
+   * D6: (diceCount) => value
+   * D8: (diceCount) => value
+   * D10: (diceCount) => value
+   * D12: (diceCount) => value
+   * D20: (diceCount) => value
    */
   ...predefined,
 
   /**
    * Roll a die of specified spot value.
    *
    * @param {number} spotvalue - The die dimension (default: 6).
+   * @param {number} diceCount - number of dice to throw.
+   *                             if not defined, defaults to 1 and returns the value directly.
+   *                             if defined, returns an array containing the random dice values.
    */
-  Die: spotvalue => {
+  Die: (spotvalue, diceCount) => {
     if (spotvalue === undefined) {
       spotvalue = 6;
     }
 
-    return Math.floor(random() * spotvalue) + 1;
+    if (diceCount === undefined) {
+      return Math.floor(random() * spotvalue) + 1;
+    } else {
+      return [...Array(diceCount).keys()].map(
+        () => Math.floor(random() * spotvalue) + 1
+      );
+    }
   },
 
   /**

diff --git a/src/core/random.test.js b/src/core/random.test.js
@@ -32,6 +32,14 @@ test('predefined dice values', () => {
     expect(result).toBeGreaterThanOrEqual(1);
     expect(result).toBeLessThanOrEqual(pair.highest);
     expect(PRNGState.get().prngstate).toBeDefined();
+
+    const multiple = pair.fn(5);
+    expect(multiple).toBeDefined();
+    expect(multiple.length).toBe(5);
+    multiple.forEach(m => {
+      expect(m).toBeGreaterThanOrEqual(1);
+      expect(m).toBeLessThanOrEqual(pair.highest);
+    });
   });
 });
 
@@ -51,6 +59,17 @@ test('Random.Die', () => {
     expect(result).toBeLessThanOrEqual(6);
     expect(PRNGState.get().prngstate).toBeDefined();
   }
+
+  {
+    const multiple = Random.Die(6, 3);
+    expect(multiple).toBeDefined();
+    expect(multiple.length).toBe(3);
+    multiple.forEach(m => {
+      expect(m).toBeGreaterThanOrEqual(1);
+      expect(m).toBeLessThanOrEqual(6);
+    });
+    expect(PRNGState.get().prngstate).toBeDefined();
+  }
 });
 
 test('Random.Number', () => {