Initial version, rolls 4 asphodice with rerolls

dice.ts

@@ -0,0 +1,185 @@
+const util = require('util');
+
+function countOccurrencesOfNumber(inputArray: Array<number>, checkNumber: number): number {
+	/*
+	return inputArray.reduce(function(n: number, val: number) {
+		return n + (val === checkNumber);
+	}, 0);
+       */
+        return inputArray.filter(c => c === checkNumber).length;
+}
+
+function randIntMinOne(max: number): number {
+	return (1 + Math.floor(Math.random() * Math.floor(max)));
+}
+
+interface Dice {
+	readonly sides: number;
+	readonly type: string;
+}
+
+enum Outcomes {
+	Success = "Success",
+	Fail = "Failure",
+	CritSuccess = "Critical Success",
+	CritFail = "Critical Failure",
+	Other = "Something Else"
+}
+
+interface DiceResult {
+	total: number;
+	dice: Array<number>;
+	olddice?: Array<number>;
+	reroll?: boolean;
+	outcome?: Outcomes;
+
+}
+
+class D10 implements Dice {
+	sides: number = 10;
+	type: string = "d10"
+
+	constructor() {
+		// this.sides = 10;
+	}
+
+	[util.inspect.custom](): string {
+		return this.type;
+	}
+
+	roll(numberToRoll: number): DiceResult {
+		let results: DiceResult = { total: 0, dice: [] };
+		for (let i = 0; i < numberToRoll; i++) {
+			results.dice.push(randIntMinOne(this.sides));
+		}
+
+		results.total = results.dice.reduce((acc: number, curr: number) => acc + curr);
+
+		return results;
+	}
+}
+
+class Asphodice extends D10 {
+	readonly type: string = "asphodice";
+	readonly passCrit: number = 10;
+	readonly failCrit: number = 1;
+	readonly successCutOff: number = 6; // this or larger
+
+	rerollHighDice (rerollDice: Array<number>): Array<number> {
+		// Re-roll the high dice (ie >= 6) for a chance of failure
+		// happens on eg 1
+		//
+		// Basically we want to remove a die from the original result,
+		// as long as that die isn't a 10, and is above the
+		// cutoff. So we filter to get rerollCandidates, find the 
+		// highest value and get the index of that value in the 
+		// original results. We use that to splice() out (remove) that
+		// value and push the rerolled dice onto the modified array
+		//
+		// Example:
+		// rerollDice: [ 8, 1, 1, 4, 7, 10] --> filter (not 10, >= 6)
+		// rerollCandidates : [8, 7] --> maxValue: 8
+		// maxIndex: 0 (in original array)
+		// rerollResult: 6
+		// rerollOutcome: [ 1, 1, 4, 7, 10, 6] --> return
+
+		let rerollCandidates: Array<number> = rerollDice.filter(die => (die < 10 && die >= this.successCutOff));
+		let maxValue: number = Math.max(...rerollCandidates);
+		let maxIndex = rerollDice.indexOf(maxValue);
+		let rerollResult: number = randIntMinOne(this.sides);
+
+		rerollDice.splice(maxIndex, 1);
+		rerollDice.push(rerollResult);
+		return rerollDice
+	}
+
+	rerollLowDice (rerollDice: Array<number>): Array<number> {
+		// Re-roll the low dice (ie < 6) for a chance of success
+		// happens on eg 10
+		//
+		// see this.rerollHighDice() for a full explanation
+
+		let rerollCandidates: Array<number> = rerollDice.filter(die => (die > 1 && die < this.successCutOff));
+		let minValue: number = Math.min(...rerollCandidates);
+		let minIndex = rerollDice.indexOf(minValue);
+		let rerollResult: number = randIntMinOne(this.sides);
+
+		rerollDice.splice(minIndex, 1);
+		rerollDice.push(rerollResult);
+		return rerollDice
+	}
+
+	allAboveCutOff (checkDice: Array<number>): boolean {
+		// if filtering those *below* cutoff results in empty set
+		// then all must be above cutoff
+		return ((checkDice.filter(die => die < this.successCutOff).length == 0));
+	}
+
+	allBelowCutOff (checkDice: Array<number>): boolean {
+		// if filtering those *above or equal to* cutoff results in empty set
+		// then all must be below cutoff
+		return ((checkDice.filter(die => die >= this.successCutOff).length == 0));
+	}
+
+	roll (numToRoll: number): DiceResult {
+		let results: DiceResult = { total: 0, dice: [] };
+
+		// Initial roll
+		for (let i = 0; i < numToRoll; i++) {
+			results.dice.push(randIntMinOne(this.sides));
+		}
+
+		// Check for re-rolls
+		// 1. if no re-rolls we can finish here
+		if (!(results.dice.includes(this.passCrit) || results.dice.includes(this.failCrit))) {
+			// results.total = results.dice.reduce((acc: number, curr: number) => acc + curr);
+			results.reroll = false;
+		} else {
+			// count successes and fails
+			let rerollGood = countOccurrencesOfNumber(results.dice, this.passCrit); 
+			let rerollBad = countOccurrencesOfNumber(results.dice, this.failCrit); 
+			
+			// 2. only reroll if they don't cancel each other out
+			if (rerollGood == rerollBad) {
+				// console.log("Good = Bad, no need to reroll");
+				results.reroll = false;
+				// results.total = results.dice.reduce((acc: number, curr: number) => acc + curr);
+			} 
+			// If all dice are above/below cutoff we don't need to reroll
+			// 3a. Above
+			else if (this.allAboveCutOff(results.dice)) {
+				console.log("All above cutoff, auto-success", results.dice);
+				results.reroll = false;
+		       	} 
+			// 3b. Below
+			else if (this.allBelowCutOff(results.dice)) {
+				console.log("All below cutoff, auto-fail", results.dice);
+				results.reroll = false;
+		       	} 
+			// Reroll
+			else {
+				// Reminder: arr1 = arr2 is a copy by reference!
+				let olddice = results.dice.slice();
+				if (rerollGood > rerollBad) {
+					// Re-roll low (<6) dice for chance of success
+					results.dice = this.rerollLowDice(results.dice);
+				} else {
+					// Re-roll high (>=6) dice for chance of failure
+					results.dice = this.rerollHighDice(results.dice);
+				}
+				results.olddice = olddice;
+				results.reroll = true;
+			}
+		}
+
+		results.total = results.dice.reduce((acc: number, curr: number) => acc + curr);
+		return results;
+	}
+}
+
+let asphodice: Asphodice  = new Asphodice();
+let number: number = 4;
+for (let i = 0; i < 10; i++) {
+	console.log("Rolling", number, asphodice);
+	console.log(asphodice.roll(4));
+}

tsconfig.json

@@ -0,0 +1,70 @@
+{
+  "compilerOptions": {
+    /* Visit https://aka.ms/tsconfig.json to read more about this file */
+
+    /* Basic Options */
+    // "incremental": true,                   /* Enable incremental compilation */
+    "target": "es5",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019', 'ES2020', or 'ESNEXT'. */
+    "module": "commonjs",                     /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', 'es2020', or 'ESNext'. */
+    // "lib": [],                             /* Specify library files to be included in the compilation. */
+    // "allowJs": true,                       /* Allow javascript files to be compiled. */
+    // "checkJs": true,                       /* Report errors in .js files. */
+    // "jsx": "preserve",                     /* Specify JSX code generation: 'preserve', 'react-native', or 'react'. */
+    // "declaration": true,                   /* Generates corresponding '.d.ts' file. */
+    // "declarationMap": true,                /* Generates a sourcemap for each corresponding '.d.ts' file. */
+    // "sourceMap": true,                     /* Generates corresponding '.map' file. */
+    // "outFile": "./",                       /* Concatenate and emit output to single file. */
+    // "outDir": "./",                        /* Redirect output structure to the directory. */
+    // "rootDir": "./",                       /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
+    // "composite": true,                     /* Enable project compilation */
+    // "tsBuildInfoFile": "./",               /* Specify file to store incremental compilation information */
+    // "removeComments": true,                /* Do not emit comments to output. */
+    // "noEmit": true,                        /* Do not emit outputs. */
+    // "importHelpers": true,                 /* Import emit helpers from 'tslib'. */
+    // "downlevelIteration": true,            /* Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. */
+    // "isolatedModules": true,               /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */
+
+    /* Strict Type-Checking Options */
+    "strict": true,                           /* Enable all strict type-checking options. */
+    // "noImplicitAny": true,                 /* Raise error on expressions and declarations with an implied 'any' type. */
+    // "strictNullChecks": true,              /* Enable strict null checks. */
+    // "strictFunctionTypes": true,           /* Enable strict checking of function types. */
+    // "strictBindCallApply": true,           /* Enable strict 'bind', 'call', and 'apply' methods on functions. */
+    // "strictPropertyInitialization": true,  /* Enable strict checking of property initialization in classes. */
+    // "noImplicitThis": true,                /* Raise error on 'this' expressions with an implied 'any' type. */
+    // "alwaysStrict": true,                  /* Parse in strict mode and emit "use strict" for each source file. */
+
+    /* Additional Checks */
+    // "noUnusedLocals": true,                /* Report errors on unused locals. */
+    // "noUnusedParameters": true,            /* Report errors on unused parameters. */
+    // "noImplicitReturns": true,             /* Report error when not all code paths in function return a value. */
+    // "noFallthroughCasesInSwitch": true,    /* Report errors for fallthrough cases in switch statement. */
+    // "noUncheckedIndexedAccess": true,      /* Include 'undefined' in index signature results */
+
+    /* Module Resolution Options */
+    // "moduleResolution": "node",            /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */
+    // "baseUrl": "./",                       /* Base directory to resolve non-absolute module names. */
+    // "paths": {},                           /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */
+    // "rootDirs": [],                        /* List of root folders whose combined content represents the structure of the project at runtime. */
+    // "typeRoots": [],                       /* List of folders to include type definitions from. */
+    "types": [ "node" ],                           /* Type declaration files to be included in compilation. */
+    // "allowSyntheticDefaultImports": true,  /* Allow default imports from modules with no default export. This does not affect code emit, just typechecking. */
+    "esModuleInterop": true,                  /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
+    // "preserveSymlinks": true,              /* Do not resolve the real path of symlinks. */
+    // "allowUmdGlobalAccess": true,          /* Allow accessing UMD globals from modules. */
+
+    /* Source Map Options */
+    // "sourceRoot": "",                      /* Specify the location where debugger should locate TypeScript files instead of source locations. */
+    // "mapRoot": "",                         /* Specify the location where debugger should locate map files instead of generated locations. */
+    // "inlineSourceMap": true,               /* Emit a single file with source maps instead of having a separate file. */
+    // "inlineSources": true,                 /* Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set. */
+
+    /* Experimental Options */
+    // "experimentalDecorators": true,        /* Enables experimental support for ES7 decorators. */
+    // "emitDecoratorMetadata": true,         /* Enables experimental support for emitting type metadata for decorators. */
+
+    /* Advanced Options */
+    "skipLibCheck": true,                     /* Skip type checking of declaration files. */
+    "forceConsistentCasingInFileNames": true  /* Disallow inconsistently-cased references to the same file. */
+  }
+}