first load

bin/lighthouse/processor.js

@@ -0,0 +1,84 @@
+/**
+ * Filters and maps lighthouse results for a simplified output
+ * If an error should be ignored, it will be converted into a warning
+ */
+const UrlPattern = require("url-pattern");
+const config = require("./config");
+const { ERROR, WARNING, SKIPPED, SUCCESS, UNKNOWN } = require("./constants");
+
+function shouldIgnoreError(auditId, url, selector) {
+  const path = new URL(url).pathname;
+
+  return config.custom.ignore[auditId]?.some((ignore) => {
+    const pattern = new UrlPattern(ignore.path);
+    return Boolean(pattern.match(path)) && selector === ignore.selector;
+  });
+}
+
+function processResults(lhr) {
+  const url = lhr.mainDocumentUrl;
+  const pageScore = lhr.categories.accessibility.score;
+
+  const audits = Object.values(lhr.audits)
+    // filter and flatten data
+    .map(({ id, title, description, score, details }) => {
+      const newItem = {
+        id,
+        url,
+        title,
+        description,
+        score,
+      };
+
+      return details === undefined || details.items.length === 0
+        ? newItem
+        : details.items.map((item) => ({
+            ...newItem,
+            selector: item.node.selector,
+            snippet: item.node.snippet,
+            explanation: item.node.explanation,
+          }));
+    })
+    .flat()
+    // map lighthouse score to a result
+    .map(({ score, ...audit }) => {
+      const newItem = { ...audit };
+
+      switch (score) {
+        case 1:
+          newItem.result = SUCCESS;
+          break;
+        case 0:
+          newItem.result = shouldIgnoreError(
+            audit.id,
+            audit.url,
+            audit.selector
+          )
+            ? WARNING
+            : ERROR;
+          break;
+        case null:
+          newItem.result = SKIPPED;
+          break;
+        default:
+          console.error(`Error: unexpected score for audit ${audit.id}`);
+          newItem.result = UNKNOWN;
+      }
+
+      return newItem;
+    });
+
+  return {
+    audits,
+    stats: {
+      success: audits.filter((audit) => audit.result === SUCCESS).length,
+      error: audits.filter((audit) => audit.result === ERROR).length,
+      skipped: audits.filter((audit) => audit.result === SKIPPED).length,
+      warning: audits.filter((audit) => audit.result === WARNING).length,
+      unknown: audits.filter((audit) => audit.result === UNKNOWN).length,
+      score: pageScore
+    },
+  };
+}
+
+module.exports = processResults;