We got a basic test working!

jest.config.js

@@ -0,0 +1,4 @@
+module.exports = {
+  preset: 'ts-jest',
+  testEnvironment: 'node',
+};

package.json

@@ -7,7 +7,10 @@
   "license": "MIT",
   "private": false,
   "devDependencies": {
+    "@types/jest": "^26.0.4",
     "@types/p5": "^0.9.0",
+    "jest": "^26.1.0",
+    "ts-jest": "^26.1.3",
     "ts-loader": "^6.2.1",
     "tslint": "^5.20.1",
     "tslint-loader": "^3.5.4",
@@ -19,7 +22,8 @@
     "p5": "^0.8.0"
   },
   "scripts": {
-		"build": "webpack",
-		"add_simulation": "func() { cp pages/template.html \"pages/$1.html\" && cp src/entry_points/template.ts src/entry_points/$1.ts; }; func"
+    "build": "webpack",
+    "test": "jest",
+    "add_simulation": "func() { cp pages/template.html \"pages/$1.html\" && cp src/entry_points/template.ts src/entry_points/$1.ts; }; func"
   }
 }

src/entry_points/domain.test.ts

@@ -0,0 +1,34 @@
+import {
+  LSystemRule,
+  LSystemRuleMap,
+  Environment,
+  Tree,
+  TreeNode,
+  TransportRule,
+  TransportRuleMap,
+  RuleName,
+  ResourceCost,
+} from "./domain";
+
+test("LSystem layer works properly", () => {
+  class TestEnvironment extends Environment {
+    costs(ruleNames: RuleName[]): ResourceCost {
+      return { water: 0, energy: 0 };
+    }
+  }
+  const environment = new TestEnvironment();
+  const lSystemRuleMap = new Map<RuleName, LSystemRule>();
+  lSystemRuleMap.set("A", new LSystemRule("A", ["A", "B"]));
+  lSystemRuleMap.set("B", new LSystemRule("B", ["A"]));
+
+  const transportRuleMap = new Map<RuleName, TransportRule>();
+
+  const tree = new Tree(lSystemRuleMap, transportRuleMap, environment);
+  const rootNode = new TreeNode("A", null);
+
+  rootNode.update(tree);
+
+  expect(rootNode.children.length).toBe(2);
+  expect(rootNode.children[0].name).toBe("A");
+  expect(rootNode.children[1].name).toBe("B");
+});

src/entry_points/domain.ts

@@ -22,8 +22,8 @@ state: energy and amount
 
 Environmental Layer
 
-root is the source of W R
-end nodes evaporate W
+root is the source of Water
+end nodes evaporate Water
 end nodes (any node?) generate E. Perhaps we could only make certain end nodes of type L generate E.
 perhaps other nodes (for the stem? can still generate a little bit to have different strategies, or we could have leaves, needles, etc)
 
@@ -64,33 +64,33 @@ A -> BC
 
 */
 
-type RuleName = string;
+export type RuleName = string;
 
-type ResourceCost = {
+export type ResourceCost = {
   water: number;
   energy: number;
 };
 
-class Environment {
+export class Environment {
   costs(ruleNames: RuleName[]): ResourceCost {
     const waterCost = ruleNames.length * 10;
     const energyCost = ruleNames.length * 10;
     return { water: waterCost, energy: energyCost };
   }
 }
 
-class Tree {
+export class Tree {
   constructor(
     public lSystemRuleMap: LSystemRuleMap,
     public transportRuleMap: TransportRuleMap,
     public environment: Environment
   ) {}
 }
 
-class TreeNode {
-  children: TreeNode[];
-  water: number;
-  energy: number;
+export class TreeNode {
+  children: TreeNode[] = [];
+  water: number = 0;
+  energy: number = 0;
 
   constructor(public name: RuleName, public parent: TreeNode | null) {}
 
@@ -126,21 +126,21 @@ class TreeNode {
   }
 }
 
-class LSystemRule {
+export class LSystemRule {
   constructor(public name: RuleName, public product: RuleName[]) {}
 }
 
-type ResourceType = "Water" | "Energy";
+export type ResourceType = "Water" | "Energy";
 
-type ResourceMap = Map<ResourceType, number>;
+export type ResourceMap = Map<ResourceType, number>;
 
-class TransportRule {
+export class TransportRule {
   constructor(
     public name: RuleName,
     public parentResourceMap: ResourceMap,
     public childResourceMap: ResourceMap
   ) {}
 }
 
-type LSystemRuleMap = Map<RuleName, LSystemRule>;
-type TransportRuleMap = Map<RuleName, TransportRule>;
+export type LSystemRuleMap = Map<RuleName, LSystemRule>;
+export type TransportRuleMap = Map<RuleName, TransportRule>;

tsconfig.json

@@ -2,25 +2,18 @@
   "compilerOptions": {
     "target": "es2016",
     "module": "es2015",
-    "lib": [
-      "es2017",
-      "dom",
-      "es6"
-    ],
+    "lib": ["es2017", "dom", "es6"],
     "sourceMap": true,
     "moduleResolution": "node",
     "downlevelIteration": true,
     "removeComments": false,
     "baseUrl": "./",
-    "typeRoots": [
-      "src/@types"
-    ],
+    "strict": true,
     "noImplicitReturns": true,
     "strictNullChecks": true,
     "noImplicitAny": true,
-    "noImplicitThis": true
+    "noImplicitThis": true,
+    "esModuleInterop": true
   },
-  "include": [
-    "src/**/*"
-  ]
-}
+  "include": ["src/**/*"]
+}