General source code refactoring

tests/fixtures/consumption-trend.html

@@ -12,25 +12,21 @@
   </head>
   <body>
     <div id="opportunities-extension-modal" class="opportunities-extension-modal" data-theme="light"></div>
+    <script src="/fixture-runtime.js"></script>
     <script>
-      window.chrome = { runtime: { onMessage: { addListener() {} } } };
 
       async function initialize() {
-        const source = await fetch("/src/content.js").then((response) => response.text());
-        const marker = /\r?\n  if \(insertTile\(\)\) \{/;
-        const exposure = `
-  window.__trendHarness = {
-    ensureStyles: ensureExtensionStyles,
-    createAccountPlanDetails,
-    createConsumptionTrendSection,
-    renderConsumptionTrendChart
-  };
-  return;
-`;
-        const testableSource = source
-          .replace("  if (!isAllowedPage()) {", "  if (false) {")
-          .replace(marker, `${exposure}\n  if (insertTile()) {`);
-        window.eval(testableSource);
+        const app = window.createFixtureApplication({
+          fetch: () => Promise.reject(new Error("Network disabled in fixture")),
+          browser: undefined,
+          chrome: undefined
+        });
+        const harness = {
+          ensureStyles: app.contentStyles.ensureExtensionStyles,
+          createAccountPlanDetails: app.consumptionPlansView.createAccountPlanDetails,
+          createConsumptionTrendSection: app.consumptionTrendController.createConsumptionTrendSection,
+          renderConsumptionTrendChart: app.consumptionChart.renderConsumptionTrendChart
+        };
 
         const plan = {
           subPlanNum: "11276098",
@@ -63,7 +59,7 @@
           return rows;
         });
 
-        window.__trendHarness.ensureStyles();
+        harness.ensureStyles();
         const overlay = document.getElementById("opportunities-extension-modal");
         overlay.dataset.theme = new URLSearchParams(window.location.search).get("theme") === "dark"
           ? "dark"
@@ -82,13 +78,13 @@
         tabs.innerHTML = '<button class="opportunities-extension-account-plan-tab" aria-selected="true"><span class="opportunities-extension-account-plan-status-indicator" data-active="true"></span>Universal Credits 11276098</button>';
         const panel = document.createElement("section");
         panel.className = "opportunities-extension-account-plan-panel";
-        const trend = window.__trendHarness.createConsumptionTrendSection(plan);
-        panel.append(window.__trendHarness.createAccountPlanDetails(plan), trend);
+        const trend = harness.createConsumptionTrendSection(plan);
+        panel.append(harness.createAccountPlanDetails(plan), trend);
         content.append(tabs, panel);
         dialog.append(header, content);
         modal.append(dialog);
         overlay.append(modal);
-        window.__trendHarness.renderConsumptionTrendChart(
+        harness.renderConsumptionTrendChart(
           trend,
           trend.querySelector(".opportunities-extension-consumption-chart"),
           items,