Add tests for _findLargestStrokeWidth

Author: adroitwhiz

package.json

@@ -39,6 +39,7 @@
     "json": "^9.0.6",
     "lodash.defaultsdeep": "4.6.1",
     "mkdirp": "^1.0.3",
+    "mock-require": "^3.0.3",
     "rimraf": "^3.0.1",
     "tap": "^11.0.1",
     "webpack": "^4.8.0",

test/stroke-width.js

@@ -0,0 +1,104 @@
+const test = require('tap').test;
+const jsdom = require('jsdom');
+const {JSDOM} = jsdom;
+
+const mockRequire = require('mock-require');
+// The font inliner uses Webpack loader require syntax, which doesn't work in Node.
+mockRequire('../src/font-inliner', () => {});
+
+const SvgRenderer = require('../src/svg-renderer');
+
+const {window} = new JSDOM();
+// The SvgRenderer constructor tries to get a canvas' context, which doesn't work in JSDOM
+window.HTMLCanvasElement.prototype.getContext = () => {};
+global.window = window;
+global.document = window.document;
+global.DOMParser = window.DOMParser;
+const parser = new window.DOMParser();
+
+const renderer = new SvgRenderer();
+
+const parseSVGString = svgString => parser.parseFromString(svgString, 'image/svg+xml').documentElement;
+
+test('stroke-width set to maximum', t => {
+    const svg = parseSVGString(`
+    <svg xmlns="http://www.w3.org/2000/svg" version="1.1" viewBox="0 0 256 256" height="256" width="256">
+        <circle r="128" cy="128" cx="128" fill="red" fill-rule="nonzero" stroke="black" stroke-width="16" />
+        <circle r="128" cy="128" cx="128" fill="blue" fill-rule="nonzero" stroke="black" stroke-width="32" />
+        <circle r="128" cy="128" cx="128" fill="green" fill-rule="nonzero" stroke="black" stroke-width="48" />
+    </svg>
+    `);
+
+    const largestStrokeWidth = renderer._findLargestStrokeWidth(svg);
+
+    t.equals(largestStrokeWidth, 48, 'stroke-width is set to largest value');
+    t.end();
+});
+
+
+test('stroke-width unset', t => {
+    const svg = parseSVGString(`
+    <svg xmlns="http://www.w3.org/2000/svg" version="1.1" viewBox="0 0 256 256" height="256" width="256">
+        <circle r="128" cy="128" cx="128" fill="red" fill-rule="nonzero" stroke="black" />
+    </svg>
+    `);
+
+    const largestStrokeWidth = renderer._findLargestStrokeWidth(svg);
+
+    t.equals(largestStrokeWidth, 1, 'stroke-width is 1 by default');
+    t.end();
+});
+
+test('stroke-width below 1', t => {
+    const svg = parseSVGString(`
+    <svg xmlns="http://www.w3.org/2000/svg" version="1.1" viewBox="0 0 256 256" height="256" width="256">
+        <circle r="128" cy="128" cx="128" fill="red" fill-rule="nonzero" stroke="black" stroke-width="0.5" />
+    </svg>
+    `);
+
+    const largestStrokeWidth = renderer._findLargestStrokeWidth(svg);
+
+    t.equals(largestStrokeWidth, 0.5, 'stroke-width is 0.5');
+    t.end();
+});
+
+test('stroke-width but no stroke', t => {
+    const svg = parseSVGString(`
+    <svg xmlns="http://www.w3.org/2000/svg" version="1.1" viewBox="0 0 256 256" height="256" width="256">
+        <circle r="128" cy="128" cx="128" fill="red" fill-rule="nonzero" stroke="black" stroke-width="16" />
+        <circle r="128" cy="128" cx="128" fill="white" fill-rule="nonzero" stroke-width="32" />
+    </svg>
+    `);
+
+    const largestStrokeWidth = renderer._findLargestStrokeWidth(svg);
+
+    t.equals(largestStrokeWidth, 16, 'stroke-width is ignored when element has no stroke attribute');
+    t.end();
+});
+
+test('stroke-width set to invalid value', t => {
+    const svg = parseSVGString(`
+    <svg xmlns="http://www.w3.org/2000/svg" version="1.1" viewBox="0 0 256 256" height="256" width="256">
+        <circle r="128" cy="128" cx="128" fill="red" fill-rule="nonzero" stroke="black" stroke-width="wrong" />
+    </svg>
+    `);
+
+    const largestStrokeWidth = renderer._findLargestStrokeWidth(svg);
+
+    t.equals(largestStrokeWidth, 1, 'invalid stroke-width defaults to 1');
+    t.end();
+});
+
+test('stroke-width on the wrong elements', t => {
+    const svg = parseSVGString(`
+    <svg xmlns="http://www.w3.org/2000/svg" version="1.1" viewBox="0 0 256 256" height="256" width="256">
+          <image href="" stroke="black" stroke-width="64" />
+          <circle r="128" cy="128" cx="128" fill="white" fill-rule="nonzero" stroke="black" stroke-width="16" />
+    </svg>
+    `);
+
+    const largestStrokeWidth = renderer._findLargestStrokeWidth(svg);
+
+    t.equals(largestStrokeWidth, 16, 'stroke-width is ignored when applied to elements that cannot have a stroke');
+    t.end();
+});