chore(axe-core): add a11y reports in dev environement

app/javascript/entrypoints/axe-core.ts

@@ -0,0 +1,156 @@
+import type { AxeResults, NodeResult, RelatedNode } from 'axe-core';
+import axe from 'axe-core';
+
+domReady().then(() => {
+  axe.run(document.body, { reporter: 'v2' }).then((results) => {
+    logToConsole(results);
+  });
+});
+
+// contrasted against Chrome default color of #ffffff
+const lightTheme = {
+  serious: '#d93251',
+  minor: '#d24700',
+  text: 'black'
+};
+
+// contrasted against Safari dark mode color of #535353
+const darkTheme = {
+  serious: '#ffb3b3',
+  minor: '#ffd500',
+  text: 'white'
+};
+
+const theme =
+  window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches
+    ? darkTheme
+    : lightTheme;
+
+const boldCourier = 'font-weight:bold;font-family:Courier;';
+const critical = `color:${theme.serious};font-weight:bold;`;
+const serious = `color:${theme.serious};font-weight:normal;`;
+const moderate = `color:${theme.minor};font-weight:bold;`;
+const minor = `color:${theme.minor};font-weight:normal;`;
+const defaultReset = `font-color:${theme.text};font-weight:normal;`;
+
+function logToConsole(results: AxeResults): void {
+  console.group('%cNew axe issues', serious);
+  results.violations.forEach((result) => {
+    let fmt: string;
+    switch (result.impact) {
+      case 'critical':
+        fmt = critical;
+        break;
+      case 'serious':
+        fmt = serious;
+        break;
+      case 'moderate':
+        fmt = moderate;
+        break;
+      case 'minor':
+        fmt = minor;
+        break;
+      default:
+        fmt = minor;
+        break;
+    }
+    console.groupCollapsed(
+      '%c%s: %c%s %s',
+      fmt,
+      result.impact,
+      defaultReset,
+      result.help,
+      result.helpUrl
+    );
+    result.nodes.forEach((node) => {
+      failureSummary(node, 'any');
+      failureSummary(node, 'none');
+    });
+    console.groupEnd();
+  });
+  console.groupEnd();
+}
+
+function failureSummary(node: NodeResult, key: AxeCoreNodeResultKey): void {
+  if (node[key].length > 0) {
+    logElement(node, console.groupCollapsed);
+    logHtml(node);
+    logFailureMessage(node, key);
+
+    let relatedNodes: RelatedNode[] = [];
+    node[key].forEach((check) => {
+      relatedNodes = relatedNodes.concat(check.relatedNodes ?? []);
+    });
+
+    if (relatedNodes.length > 0) {
+      console.groupCollapsed('Related nodes');
+      relatedNodes.forEach((relatedNode) => {
+        logElement(relatedNode, console.log);
+        logHtml(relatedNode);
+      });
+      console.groupEnd();
+    }
+
+    console.groupEnd();
+  }
+}
+
+function logFailureMessage(node: NodeResult, key: AxeCoreNodeResultKey): void {
+  // this exists on axe but we don't export it as part of the typescript
+  // namespace, so just let me use it as I need
+  const message: string = (
+    axe as unknown as AxeWithAudit
+  )._audit.data.failureSummaries[key].failureMessage(
+    node[key].map((check) => check.message || '')
+  );
+
+  console.error(message);
+}
+
+function logElement(
+  node: NodeResult | RelatedNode,
+  logFn: (...args: unknown[]) => void
+): void {
+  const el = document.querySelector(node.target.toString());
+  if (!el) {
+    logFn('Selector: %c%s', boldCourier, node.target.toString());
+  } else {
+    logFn('Element: %o', el);
+  }
+}
+
+function logHtml(node: NodeResult | RelatedNode): void {
+  console.log('HTML: %c%s', boldCourier, node.html);
+}
+
+type AxeCoreNodeResultKey = 'any' | 'all' | 'none';
+
+interface AxeWithAudit {
+  _audit: {
+    data: {
+      failureSummaries: {
+        any: {
+          failureMessage: (args: string[]) => string;
+        };
+        all: {
+          failureMessage: (args: string[]) => string;
+        };
+        none: {
+          failureMessage: (args: string[]) => string;
+        };
+      };
+    };
+  };
+}
+
+function domReady() {
+  return new Promise<void>((resolve) => {
+    if (document.readyState == 'loading') {
+      document.addEventListener('DOMContentLoaded', () => resolve(), {
+        once: true
+      });
+    } else {
+      resolve();
+    }
+  });
+}

app/views/layouts/application.html.haml

@@ -48,6 +48,8 @@
       - if content_for?(:footer)
         = content_for(:footer)
 
+      - if Rails.env.development?
+        = vite_typescript_tag 'axe-core'
       = yield :charts_js
 
     // Container for custom turbo-stream actions

package.json

@@ -60,6 +60,7 @@
     "@vitejs/plugin-legacy": "^1.2.3",
     "@vitejs/plugin-react": "^1.1.4",
     "@vitejs/plugin-react-refresh": "^1.3.0",
+    "axe-core": "^4.4.2",
     "del-cli": "^4.0.1",
     "eslint": "^8.17.0",
     "eslint-config-prettier": "^8.5.0",

yarn.lock

@@ -3107,6 +3107,11 @@ aws4@^1.8.0:
   resolved "https://registry.yarnpkg.com/aws4/-/aws4-1.11.0.tgz#d61f46d83b2519250e2784daf5b09479a8b41c59"
   integrity sha512-xh1Rl34h6Fi1DC2WWKfxUTVqRsNnr6LsKz2+hfwDxQJWmrx8+c7ylaqBMcHfl1U1r2dsifOvKX3LQuLNZ+XSvA==
 
+axe-core@^4.4.2:
+  version "4.4.2"
+  resolved "https://registry.yarnpkg.com/axe-core/-/axe-core-4.4.2.tgz#dcf7fb6dea866166c3eab33d68208afe4d5f670c"
+  integrity sha512-LVAaGp/wkkgYJcjmHsoKx4juT1aQvJyPcW09MLCjVTh3V2cc6PnyempiLMNH5iMdfIX/zdbjUx2KDjMLCTdPeA==
+
 babel-plugin-dynamic-import-node@^2.3.3:
   version "2.3.3"
   resolved "https://registry.yarnpkg.com/babel-plugin-dynamic-import-node/-/babel-plugin-dynamic-import-node-2.3.3.tgz#84fda19c976ec5c6defef57f9427b3def66e17a3"