Add Jest test framework (#43)

* Add Jest setup and write a test

* Code coverage?

* Update calculateOverriddenConfig test

* Throw if register gets bad input

.gitignore

@@ -5,6 +5,7 @@ node_modules
 /target
 /pkg
 /wasm-pack.log
+coverage
 
 scripts/*_exe.sh
 test/federalist/*.txt

.travis.yml

@@ -14,6 +14,9 @@ jobs:
     - yarn install
     script:
     - yarn eslint js/*
+    - yarn test --coverage
+    after_success: |
+      bash <(curl -s https://codecov.io/bash) -cF javascript
 
   - language: rust
     rust: stable

jest.config.js

@@ -0,0 +1,6 @@
+module.exports = {
+  preset: "ts-jest",
+  testEnvironment: "node",
+  modulePathIgnorePatterns: ["<rootDir>/target/*", "<rootDir>/pkg/*"],
+  collectCoverageFrom: ["js/**/*.{js,ts}"]
+};

js/config.test.ts

@@ -0,0 +1,15 @@
+import { defaultConfig, calculateOverriddenConfig } from "./config";
+
+test("correctly overrides default config", () => {
+  const expected = {
+    showProgress: true,
+    printIndexInfo: false,
+    showScores: true
+  };
+
+  const generated = calculateOverriddenConfig({
+    showScores: true
+  });
+
+  expect(generated).toMatchObject(expected);
+});

js/config.ts

@@ -4,7 +4,7 @@ export interface Configuration {
   showScores: boolean;
 }
 
-const defaultConfig: Readonly<Configuration> = {
+export const defaultConfig: Readonly<Configuration> = {
   showProgress: true,
   printIndexInfo: false,
   showScores: false
@@ -16,7 +16,7 @@ export function calculateOverriddenConfig(
   const output: Configuration = defaultConfig;
 
   for (const key of Object.keys(defaultConfig) as Array<keyof Configuration>) {
-    if (overrides[key]) {
+    if (overrides[key] !== undefined) {
       const overrideVal = overrides[key] as boolean;
       output[key] = overrideVal;
     }

js/index.js

@@ -8,8 +8,8 @@ import init, {
 import WasmQueue from "./wasmqueue";
 import { Entity } from "./entity";
 import { loadIndexFromUrl } from "./indexLoader";
-
-import { defaultConfig, calculateOverriddenConfig } from "./config";
+import { assert } from "./util";
+import { defaultConfig } from "./config";
 
 const prod = process.env.NODE_ENV === "production";
 const wasmUrl = prod
@@ -174,8 +174,33 @@ function handleLoadedIndex(event, entity) {
   }
 }
 
+function difference(arr1, arr2) {
+  const set1 = new Set(arr1);
+  const set2 = new Set(arr2);
+  const diff = new Set([...set1].filter(x => !set2.has(x)));
+  return diff;
+}
+
 export function register(name, url, config = {}) {
-  // assert that name is a string, url is a string, and config is a Partial<Configuration>
+  if (typeof name !== "string") {
+    throw new Error("Index registration name must be a string.");
+  }
+
+  if (typeof url !== "string") {
+    throw new Error("URL must be a string.");
+  }
+
+  let configKeyDiff = difference(
+    Object.keys(config),
+    Object.keys(defaultConfig)
+  );
+  if (configKeyDiff.size > 0) {
+    throw new Error(
+      `Invalid key${
+        configKeyDiff > 1 ? "s" : ""
+      } in config object: ${JSON.stringify(Array.from(configKeyDiff))}`
+    );
+  }
 
   let entity = new Entity(name, url, config);
   entities[name] = entity;

package.json

@@ -20,6 +20,7 @@
   "homepage": "https://stork-search.net",
   "devDependencies": {
     "@open-wc/webpack-import-meta-loader": "^0.4.1",
+    "@types/jest": "^25.2.3",
     "@typescript-eslint/eslint-plugin": "^3.0.0",
     "@typescript-eslint/parser": "^3.0.0",
     "@wasm-tool/wasm-pack-plugin": "^1.2.0",
@@ -33,8 +34,10 @@
     "eslint-plugin-import": "^2.20.1",
     "eslint-plugin-prettier": "^3.1.2",
     "http-server": "^0.12.1",
+    "jest": "^26.0.1",
     "prettier": "^2.0.1",
     "source-map-loader": "^0.2.4",
+    "ts-jest": "^26.0.0",
     "typescript": "~3.7.0",
     "webpack": "^4.41.4",
     "webpack-cli": "^3.3.10"
@@ -50,6 +53,7 @@
     "build:js:prod": "yarn webpack --mode=production",
     "build:prod": "yarn install && yarn build:wasm:prod && yarn build:test-index:federalist && yarn build:js:prod",
     "lint": "yarn eslint js/*",
+    "test": "jest",
     "serve": "yarn http-server ./dist -o -p 8025 -s -c-1"
   },
   "//": [