Increase test coverage to 100%, ensure it stays.

Author: Walker

.gitignore

@@ -6,3 +6,4 @@ tmp/**/*
 .idea/**/*
 *.iml
 *.log
+coverage

package.json

@@ -38,7 +38,17 @@
         "format":
             "prettier --write --single-quote --tab-width=4 lib/**/*.js test/**/*.js",
         "lint": "eslint .",
-        "test": "jest"
+        "test": "jest --coverage"
     },
-    "files": ["lib"]
+    "files": ["lib"],
+    "jest": {
+        "coverageThreshold": {
+            "global": {
+                "branches": 100,
+                "functions": 100,
+                "lines": 100,
+                "statements": 100
+            }
+        }
+    }
 }

test/writer.test.js

@@ -1,12 +1,17 @@
 'use strict';
 
-/* global test, expect */
+/* global test, expect, beforeEach */
 
 const path = require('path');
 const { hasher } = require('asset-pipe-common');
 const { identifyCssModule, bundleCssModule } = require('../lib/util.js');
 const Writer = require('..');
 
+beforeEach(() => {
+    jest.clearAllMocks();
+    jest.resetModules();
+});
+
 test('identifyCssModule(filePath)', async () => {
     expect.assertions(1);
     const filePath = path.join(__dirname, 'test-assets/my-module-1/main.css');
@@ -205,3 +210,39 @@ test('new Writer([filePath]) ensures valid filePaths provided in array', () => {
 
     expect(result).toThrow();
 });
+
+test('writer emits error', done => {
+    expect.assertions(1);
+    jest.mock('../lib/util.js', () => ({
+        bundleCssModule () {
+            throw new Error();
+        },
+        identifyCssModule () {
+            throw new Error();
+        },
+    }));
+    const Writer = require('..');
+    const filePath = path.join(__dirname, 'test-assets/my-module-1/main.css');
+
+    const writer = new Writer(filePath);
+
+    writer.on('error', error => {
+        expect(error).toBeInstanceOf(Error);
+        done();
+    });
+    writer.on('data', () => {});
+});
+
+test('new Writer() emits nothing but does not break', done => {
+    const writer = new Writer();
+    const items = [];
+
+    writer.on('data', item => {
+        items.push(item);
+    });
+
+    writer.on('end', () => {
+        expect(items.length).toBe(0);
+        done();
+    });
+});