Tests (#471)

* some basic tests

* corrected svg which didn't pass tests

* Updated apple_music.svg

* corrected offset=0

* updated README.md

test/test.js

@@ -0,0 +1,34 @@
+const expect = require("chai").expect
+const fs = require("fs")
+const fetch = require("node-fetch")
+
+const svgDir = __dirname + "/../images/svg/"
+
+const files = fs.readdirSync(svgDir)
+
+files.forEach((filename, i) => {
+    if (! filename.endsWith(".svg")) {return}
+    const filepath = svgDir + filename
+    describe(filename, async () => {
+        it("should exists", () => {
+             expect(fs.existsSync(filepath)).to.be.true
+        })
+
+        it("should be under 1KB", () => {
+            expect(fs.statSync(filepath).size).to.be.lessThan(1024)
+        })
+
+        it("should be validated by the w3c validator", async () => {
+            await fetch("https://validator.w3.org/nu/?out=gnu", {
+                    method: "POST",
+                    body: fs.readFileSync(filepath, "utf8").replace(/aria-label="[^"]+"/g, ""),
+                    headers: new fetch.Headers([["Content-Type", "application/xml"]])
+                })
+                .then(res => (console.log(i + 1, "/", files.length), res))
+                .then(res => res.text())
+                .then(res => {
+                    expect(res).to.be.empty
+                })
+        })
+    })
+})