i18n: inject strings from trace engine npm package

core/computed/trace-engine-result.js

@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+import * as i18n from '../lib/i18n/i18n.js';
 import * as TraceEngine from '../lib/trace-engine.js';
 import {makeComputedArtifact} from './computed-artifact.js';
 import {CumulativeLayoutShift} from './metrics/cumulative-layout-shift.js';
@@ -35,9 +36,34 @@ class TraceEngineResult {
     ), {});
     if (!processor.parsedTrace) throw new Error('No data');
     if (!processor.insights) throw new Error('No insights');
+    this.localizeInsights(processor.insights);
     return {data: processor.parsedTrace, insights: processor.insights};
   }
 
+  /**
+   * @param {import('@paulirish/trace_engine/models/trace/insights/types.js').TraceInsightSets} insightSets
+   */
+  static localizeInsights(insightSets) {
+    for (const insightSet of insightSets.values()) {
+      for (const [name, model] of Object.entries(insightSet.model)) {
+        if (model instanceof Error) {
+          continue;
+        }
+
+        const key = `node_modules/@paulirish/trace_engine/models/trace/insights/${name}.js`;
+        const str_ = i18n.createIcuMessageFn(key, {
+          title: model.title,
+          description: model.description,
+        });
+
+        // @ts-expect-error coerce to string, should be fine
+        model.title = str_(model.title);
+        // @ts-expect-error coerce to string, should be fine
+        model.description = str_(model.description);
+      }
+    }
+  }
+
   /**
    * @param {{trace: LH.Trace}} data
    * @param {LH.Artifacts.ComputedContext} context

core/scripts/i18n/collect-strings.js

@@ -766,6 +766,54 @@ function checkKnownFixedCollisions(strings) {
   }
 }
 
+/**
+ * @param {Record<any, any>} obj
+ * @return {Record<any, any>}
+ */
+function sortObject(obj) {
+  return Object.keys(obj).sort().reduce(function(result, key) {
+    // @ts-expect-error
+    result[key] = obj[key];
+    return result;
+  }, {});
+}
+
+/**
+ * Inject translated strings from `node_modules/@paulirish/trace_engine`. This avoids Lighthouse
+ * re-translating these same strings.
+ */
+function injectTraceEngineStrings() {
+  const traceEngineStringsDir = `${LH_ROOT}/node_modules/@paulirish/trace_engine/locales`;
+  const lhTraceStringsDir = `${LH_ROOT}/shared/localization/locales`;
+  for (const file of glob.sync(`${lhTraceStringsDir}/*.json`)) {
+    let name = path.basename(file);
+    if (name.endsWith('.ctc.json')) {
+      continue;
+    }
+
+    if (name === 'ar-XB.json') {
+      name = 'ar.json';
+    }
+
+    if (['en-XA.json'].includes(name)) {
+      continue;
+    }
+
+    const traceEnginePath = `${traceEngineStringsDir}/${name}`;
+    if (!fs.existsSync(traceEnginePath)) {
+      throw new Error(`expected locale file to exist: ${traceEnginePath}`);
+    }
+
+    const traceEngineStrings = JSON.parse(fs.readFileSync(traceEnginePath, 'utf-8'));
+    const strings = JSON.parse(fs.readFileSync(file, 'utf-8'));
+    for (const [key, value] of Object.entries(traceEngineStrings)) {
+      strings[`node_modules/@paulirish/trace_engine/${key.replace('.ts', '.js')}`] = value;
+    }
+
+    fs.writeFileSync(file, JSON.stringify(sortObject(strings), null, 2) + '\n');
+  }
+}
+
 async function main() {
   /** @type {Record<string, CtcMessage>} */
   const strings = {};
@@ -793,6 +841,7 @@ async function main() {
 
   // Remove any obsolete strings in existing LHL files.
   console.log('Checking for out-of-date LHL messages...');
+  injectTraceEngineStrings();
   pruneObsoleteLhlMessages();
 
   // Report on translation progress.

core/test/fixtures/user-flows/reports/sample-flow-result.json

@@ -6942,8 +6942,8 @@
             "dropdownSaveGist": "Save as Gist",
             "dropdownSaveHTML": "Save as HTML",
             "dropdownSaveJSON": "Save as JSON",
-            "dropdownViewer": "Open in Viewer",
             "dropdownViewUnthrottledTrace": "View Unthrottled Trace",
+            "dropdownViewer": "Open in Viewer",
             "errorLabel": "Error!",
             "errorMissingAuditInfo": "Report error: no audit information",
             "expandView": "Expand view",
@@ -11724,8 +11724,8 @@
             "dropdownSaveGist": "Save as Gist",
             "dropdownSaveHTML": "Save as HTML",
             "dropdownSaveJSON": "Save as JSON",
-            "dropdownViewer": "Open in Viewer",
             "dropdownViewUnthrottledTrace": "View Unthrottled Trace",
+            "dropdownViewer": "Open in Viewer",
             "errorLabel": "Error!",
             "errorMissingAuditInfo": "Report error: no audit information",
             "expandView": "Expand view",
@@ -16922,8 +16922,8 @@
             "dropdownSaveGist": "Save as Gist",
             "dropdownSaveHTML": "Save as HTML",
             "dropdownSaveJSON": "Save as JSON",
-            "dropdownViewer": "Open in Viewer",
             "dropdownViewUnthrottledTrace": "View Unthrottled Trace",
+            "dropdownViewer": "Open in Viewer",
             "errorLabel": "Error!",
             "errorMissingAuditInfo": "Report error: no audit information",
             "expandView": "Expand view",
@@ -24858,8 +24858,8 @@
             "dropdownSaveGist": "Save as Gist",
             "dropdownSaveHTML": "Save as HTML",
             "dropdownSaveJSON": "Save as JSON",
-            "dropdownViewer": "Open in Viewer",
             "dropdownViewUnthrottledTrace": "View Unthrottled Trace",
+            "dropdownViewer": "Open in Viewer",
             "errorLabel": "Error!",
             "errorMissingAuditInfo": "Report error: no audit information",
             "expandView": "Expand view",

core/test/results/sample_v2.json

@@ -8988,8 +8988,8 @@
       "dropdownSaveGist": "Save as Gist",
       "dropdownSaveHTML": "Save as HTML",
       "dropdownSaveJSON": "Save as JSON",
-      "dropdownViewer": "Open in Viewer",
       "dropdownViewUnthrottledTrace": "View Unthrottled Trace",
+      "dropdownViewer": "Open in Viewer",
       "errorLabel": "Error!",
       "errorMissingAuditInfo": "Report error: no audit information",
       "expandView": "Expand view",

package.json

@@ -181,7 +181,7 @@
     "webtreemap-cdt": "^3.2.1"
   },
   "dependencies": {
-    "@paulirish/trace_engine": "0.0.38",
+    "@paulirish/trace_engine": "0.0.39",
     "@sentry/node": "^7.0.0",
     "axe-core": "^4.10.2",
     "chrome-launcher": "^1.1.2",