Bug 1545312 - Make L10nRegistry handle removed sources. r=mossop

Differential Revision: https://phabricator.services.mozilla.com/D28270

--HG--
extra : moz-landing-system : lando

intl/l10n/L10nRegistry.jsm

@@ -312,7 +312,8 @@ async function* generateResourceSetsForLocale(locale, sourcesOrder, resourceIds,
     // loop, but if it's somewhere in the middle, we can
     // safely bail from the whole branch.
     for (let [idx, sourceName] of order.entries()) {
-      if (L10nRegistry.sources.get(sourceName).hasFile(locale, resourceIds[idx]) === false) {
+      const source = L10nRegistry.sources.get(sourceName);
+      if (!source || source.hasFile(locale, resourceIds[idx]) === false) {
         if (idx === order.length - 1) {
           continue;
         } else {
@@ -371,7 +372,8 @@ function* generateResourceSetsForLocaleSync(locale, sourcesOrder, resourceIds, r
     // loop, but if it's somewhere in the middle, we can
     // safely bail from the whole branch.
     for (let [idx, sourceName] of order.entries()) {
-      if (L10nRegistry.sources.get(sourceName).hasFile(locale, resourceIds[idx]) === false) {
+      const source = L10nRegistry.sources.get(sourceName);
+      if (!source || source.hasFile(locale, resourceIds[idx]) === false) {
         if (idx === order.length - 1) {
           continue;
         } else {
@@ -526,9 +528,13 @@ const PSEUDO_STRATEGIES = {
  * @param {Array} resourceIds
  * @returns {Promise<FluentBundle>}
  */
-async function generateResourceSet(locale, sourcesOrder, resourceIds) {
+function generateResourceSet(locale, sourcesOrder, resourceIds) {
   return Promise.all(resourceIds.map((resourceId, i) => {
-    return L10nRegistry.sources.get(sourcesOrder[i]).fetchFile(locale, resourceId);
+    const source = L10nRegistry.sources.get(sourcesOrder[i]);
+    if (!source) {
+      return false;
+    }
+    return source.fetchFile(locale, resourceId);
   }));
 }
 
@@ -544,7 +550,11 @@ async function generateResourceSet(locale, sourcesOrder, resourceIds) {
  */
 function generateResourceSetSync(locale, sourcesOrder, resourceIds) {
   return resourceIds.map((resourceId, i) => {
-    return L10nRegistry.sources.get(sourcesOrder[i]).fetchFile(locale, resourceId, {sync: true});
+    const source = L10nRegistry.sources.get(sourcesOrder[i]);
+    if (!source) {
+      return false;
+    }
+    return source.fetchFile(locale, resourceId, {sync: true});
   });
 }
 

intl/l10n/test/test_l10nregistry.js

@@ -459,3 +459,31 @@ add_task(async function test_hasSource() {
   equal(L10nRegistry.hasSource("app"), true, "hasSource returns true after registering a source");
   L10nRegistry.sources.clear();
 });
+
+/**
+ * This test verifies that we handle correctly a scenario where a source
+ * is being removed while the iterator operates.
+ */
+add_task(async function test_remove_source_mid_iter_cycle() {
+  let oneSource = new FileSource("platform", ["en-US"], "./platform/data/locales/{locale}/");
+  L10nRegistry.registerSource(oneSource);
+
+  let secondSource = new FileSource("app", ["pl"], "./app/data/locales/{locale}/");
+  L10nRegistry.registerSource(secondSource);
+
+  fs = {
+    "./platform/data/locales/en-US/test.ftl": "key = platform value",
+    "./app/data/locales/pl/test.ftl": "key = app value",
+  };
+
+  let bundles = L10nRegistry.generateBundles(["en-US", "pl"], ["test.ftl"]);
+
+  let bundle0 = await bundles.next();
+
+  L10nRegistry.removeSource("app");
+
+  equal((await bundles.next()).done, true);
+
+  // cleanup
+  L10nRegistry.sources.clear();
+});

intl/l10n/test/test_l10nregistry_sync.js

@@ -451,3 +451,31 @@ add_task(function test_parallel_io() {
   L10nRegistry.sources.clear();
   L10nRegistry.load = originalLoad;
 });
+
+/**
+ * This test verifies that we handle correctly a scenario where a source
+ * is being removed while the iterator operates.
+ */
+add_task(function test_remove_source_mid_iter_cycle() {
+  let oneSource = new FileSource("platform", ["en-US"], "./platform/data/locales/{locale}/");
+  L10nRegistry.registerSource(oneSource);
+
+  let secondSource = new FileSource("app", ["pl"], "./app/data/locales/{locale}/");
+  L10nRegistry.registerSource(secondSource);
+
+  fs = {
+    "./platform/data/locales/en-US/test.ftl": "key = platform value",
+    "./app/data/locales/pl/test.ftl": "key = app value",
+  };
+
+  let bundles = L10nRegistry.generateBundlesSync(["en-US", "pl"], ["test.ftl"]);
+
+  let bundle0 = bundles.next();
+
+  L10nRegistry.removeSource("app");
+
+  equal((bundles.next()).done, true);
+
+  // cleanup
+  L10nRegistry.sources.clear();
+});