allow populationSize = null

README.md

@@ -55,7 +55,7 @@ seriesComparison.C.significant; //=> true
 ### Development
 
     $ yarn install
-    $ yarn test:watch
+    $ yarn tdd
 
 ### Credits
 

package.json

@@ -1,30 +1,30 @@
 {
-  "name": "zigne",
-  "version": "0.0.7",
-  "description": "Calculate statistical significance.",
-  "main": "./dist/zigne.node.js",
-  "browser": "./dist/zigne.browser.js",
-  "repository": "https://github.com/jarib/zigne",
-  "author": "[email protected]",
-  "license": "MIT",
-  "scripts": {
-    "build": "NODE_ENV=production webpack",
-    "prepare": "yarn build",
-    "test": "NODE_ENV=test jest src/*.test.js",
-    "test:watch": "NODE_ENV=test jest --watch src/*.test.js"
-  },
-  "files": [
-    "dist"
-  ],
-  "devDependencies": {
-    "@babel/core": "^7.4.4",
-    "@babel/plugin-proposal-object-rest-spread": "^7.4.4",
-    "@babel/preset-env": "^7.4.4",
-    "babel-jest": "^24.8.0",
-    "babel-loader": "^8.0.6",
-    "jest": "^24.8.0",
-    "regenerator-runtime": "^0.11.1",
-    "webpack": "^4.1.1",
-    "webpack-cli": "^3.3.2"
-  }
+    "name": "zigne",
+    "version": "0.0.7",
+    "description": "Calculate statistical significance.",
+    "main": "./dist/zigne.node.js",
+    "browser": "./dist/zigne.browser.js",
+    "repository": "https://github.com/jarib/zigne",
+    "author": "[email protected]",
+    "license": "MIT",
+    "scripts": {
+        "build": "NODE_ENV=production webpack",
+        "prepare": "yarn build",
+        "test": "NODE_ENV=test jest src/*.test.js",
+        "tdd": "NODE_ENV=test jest --watch src/*.test.js"
+    },
+    "files": [
+        "dist"
+    ],
+    "devDependencies": {
+        "@babel/core": "^7.4.4",
+        "@babel/plugin-proposal-object-rest-spread": "^7.4.4",
+        "@babel/preset-env": "^7.4.4",
+        "babel-jest": "^24.8.0",
+        "babel-loader": "^8.0.6",
+        "jest": "^24.8.0",
+        "regenerator-runtime": "^0.11.1",
+        "webpack": "^4.1.1",
+        "webpack-cli": "^3.3.2"
+    }
 }

src/Series.js

@@ -108,8 +108,9 @@ export class Item {
         }
 
         if (
-            (populationSize && populationSize < left.sampleSize) ||
-            populationSize < right.sampleSize
+            populationSize &&
+            (populationSize < left.sampleSize ||
+                populationSize < right.sampleSize)
         ) {
             throw new Error('population size must be greater than sample size');
         }

src/index.test.js

@@ -238,8 +238,39 @@ test('it compares two values from the same sample (A)', () => {
 test('it compares two values from the same sample (B)', () => {
     const sampleSize = 220;
 
-    const Kåre = zigne.item({ name: 'Kåre', percentage: 58, sampleSize });
-    const Gro = zigne.item({ name: 'Gro', percentage: 42, sampleSize });
+    const Kåre = zigne.item({
+        name: 'Kåre',
+        percentage: 58,
+        sampleSize,
+    });
+
+    const Gro = zigne.item({
+        name: 'Gro',
+        percentage: 42,
+        sampleSize,
+    });
+    const diff = Kåre.compare(Gro, { sameSample: true, test: 'oneTailed' });
+
+    expect(diff.marginOfError).toBeCloseTo(12.27, 1);
+    expect(diff.significant).toBe(true);
+});
+
+test('it ignores population size if null', () => {
+    const sampleSize = 220;
+
+    const Kåre = zigne.item({
+        name: 'Kåre',
+        percentage: 58,
+        sampleSize,
+        populationSize: null,
+    });
+
+    const Gro = zigne.item({
+        name: 'Gro',
+        percentage: 42,
+        sampleSize,
+        populationSize: null,
+    });
     const diff = Kåre.compare(Gro, { sameSample: true, test: 'oneTailed' });
 
     expect(diff.marginOfError).toBeCloseTo(12.27, 1);