Drop: Select quality of cards based on drop rates

dropRateTest.js

@@ -0,0 +1,45 @@
+const { QUALITY, QUALITY_NAMES } = require('./config/constants');
+let results = [];
+let drops = 1000;
+let header = `⫭=== Quality distribution for ${drops.toLocaleString()} drops: ===⫬`;
+console.log(header);
+console.log(`|${' '.repeat(header.length-2)}|`);
+for ( let  i =  0 ; i <  drops ; i++) {
+    //generate rarity based on drop rate
+    let quality = undefined;
+    let roll = Math.random() * 100;
+    if (roll <= 45.0) {
+        quality = QUALITY.BAD;
+    }
+    if (roll > 45.0) {
+        quality = QUALITY.OK;
+    }
+    if (roll > 70.0) {
+        quality = QUALITY.GOOD;
+    }
+    if (roll > 85.0) {
+        quality = QUALITY.GREAT;
+    }
+    if (roll > 95.0) {
+     quality = QUALITY.EXCELLENT;
+    }
+    if (roll > 99.9) {
+        quality = QUALITY.SHINY;
+    }
+    results.push(quality);
+}
+
+//count the number of times each quality appears
+let counts = {};
+results.forEach(function(x) { counts[x] = (counts[x] || 0)+1; });
+//print results with percentages
+let p_total = 0;
+for (let key in counts) {
+    let p = counts[key]/results.length * 100;
+    p_total += p;
+    let cpStr = `${counts[key].toLocaleString()} (${p}%)`;
+    let fStr = `| ${key}/${QUALITY_NAMES[key]}${' '.repeat(10-QUALITY_NAMES[key].length)}: ${cpStr}`;
+    console.log(`${fStr}${' '.repeat(header.length-fStr.length-1)}|`);
+}
+console.log(`⌊${'_'.repeat(header.length-2)}⌋`);
+