build: Initial linting setup (#1560)

* sets up linting config and runs `yarn lint --fix` once, so that all changes will show up correctly in future PRs.

* Note that there are still a lot of linter errors.

test/browser/browserIntegration.ts

@@ -1,30 +1,35 @@
-import assert from 'assert'
-import puppeteer from 'puppeteer'
+import { expect, assert } from "chai";
+import puppeteer from "puppeteer";
 
-describe("Browser Tests", () => {
-    it("Integration Tests", async () => {
-        const browser = await puppeteer.launch({"headless": true});
-        try {
-            const page = await browser.newPage().catch();    
-            await page.goto(`file:///${__dirname}/../localIntegrationRunner.html`);    
+describe("Browser Tests", function () {
+  it("Integration Tests", async function () {
+    const browser = await puppeteer.launch({ headless: true });
+    try {
+      const page = await browser.newPage().catch();
+      await page.goto(`file:///${__dirname}/../localIntegrationRunner.html`);
 
-            await page.waitForFunction('document.querySelector("body").innerText.includes("submit multisigned transaction")');
+      await page.waitForFunction(
+        'document.querySelector("body").innerText.includes("submit multisigned transaction")'
+      );
 
-            const fails = await page.evaluate(() => {
-                return document.querySelector('.failures').textContent
-            })
-            const passes = await page.evaluate(() => {
-                return document.querySelector('.passes').textContent
-            })
+      const fails = await page.evaluate(() => {
+        const element = document.querySelector(".failures");
 
-            assert.equal(fails, "failures: 0")
-            assert.notEqual(passes, "passes: 0")
+        return element == null ? null : element.textContent;
+      });
+      const passes = await page.evaluate(() => {
+        const element = document.querySelector(".passes");
 
-        } catch (err) {
-            console.log(err)
-            assert(false)
-        } finally {
-            await browser.close();
-        }
-    }).timeout(40000)
-}) 
+        return element == null ? null : element.textContent;
+      });
+
+      expect(fails).to.equal("failures: 0");
+      expect(passes).to.not.equal("passes: 0");
+    } catch (err) {
+      console.log(err);
+      assert(false);
+    } finally {
+      await browser.close();
+    }
+  }).timeout(40000);
+});