fix(@angular/cli): allow for private use language subtags

Fixes:  #17163

packages/angular/cli/lib/config/schema.json

@@ -393,7 +393,7 @@
                   "description": "Specifies the source locale of the application.",
                   "default": "en-US",
                   "$comment": "IETF BCP 47 language tag (simplified)",
-                  "pattern": "^[a-zA-Z]{2,3}(-[a-zA-Z]{4})?(-([a-zA-Z]{2}|[0-9]{3}))?(-[a-zA-Z]{5,8})?$"
+                  "pattern": "^[a-zA-Z]{2,3}(-[a-zA-Z]{4})?(-([a-zA-Z]{2}|[0-9]{3}))?(-[a-zA-Z]{5,8})?(-x(-[a-zA-Z0-9]{1,8})+)?$"
                 },
                 {
                   "type": "object",
@@ -402,7 +402,7 @@
                     "code": {
                       "type": "string",
                       "description": "Specifies the locale code of the source locale",
-                      "pattern": "^[a-zA-Z]{2,3}(-[a-zA-Z]{4})?(-([a-zA-Z]{2}|[0-9]{3}))?(-[a-zA-Z]{5,8})?$"
+                      "pattern": "^[a-zA-Z]{2,3}(-[a-zA-Z]{4})?(-([a-zA-Z]{2}|[0-9]{3}))?(-[a-zA-Z]{5,8})?(-x(-[a-zA-Z0-9]{1,8})+)?$"
                     },
                     "baseHref": {
                       "type": "string",
@@ -417,7 +417,7 @@
               "type": "object",
               "additionalProperties": false,
               "patternProperties": {
-                "^[a-zA-Z]{2,3}(-[a-zA-Z]{4})?(-([a-zA-Z]{2}|[0-9]{3}))?(-[a-zA-Z]{5,8})?$": {
+                "^[a-zA-Z]{2,3}(-[a-zA-Z]{4})?(-([a-zA-Z]{2}|[0-9]{3}))?(-[a-zA-Z]{5,8})?(-x(-[a-zA-Z0-9]{1,8})+)?$": {
                   "oneOf": [
                     {
                       "type": "string",
@@ -2081,7 +2081,7 @@
             "minItems": 1,
             "items": {
               "type": "string",
-              "pattern": "^[a-zA-Z]{2,3}(-[a-zA-Z]{4})?(-([a-zA-Z]{2}|[0-9]{3}))?(-[a-zA-Z]{5,8})?$"
+              "pattern": "^[a-zA-Z]{2,3}(-[a-zA-Z]{4})?(-([a-zA-Z]{2}|[0-9]{3}))?(-[a-zA-Z]{5,8})?(-x(-[a-zA-Z0-9]{1,8})+)?$"
             }
           }
         ]

packages/angular_devkit/build_angular/src/browser/schema.json

@@ -211,7 +211,7 @@
           "minItems": 1,
           "items": {
             "type": "string",
-            "pattern": "^[a-zA-Z]{2,3}(-[a-zA-Z]{4})?(-([a-zA-Z]{2}|[0-9]{3}))?(-[a-zA-Z]{5,8})?$"
+            "pattern": "^[a-zA-Z]{2,3}(-[a-zA-Z]{4})?(-([a-zA-Z]{2}|[0-9]{3}))?(-[a-zA-Z]{5,8})?(-x(-[a-zA-Z0-9]{1,8})+)?$"
           }
         }
       ]

packages/angular_devkit/build_angular/src/server/schema.json

@@ -175,7 +175,7 @@
           "minItems": 1,
           "items": {
             "type": "string",
-            "pattern": "^[a-zA-Z]{2,3}(-[a-zA-Z]{4})?(-([a-zA-Z]{2}|[0-9]{3}))?(-[a-zA-Z]{5,8})?$"
+            "pattern": "^[a-zA-Z]{2,3}(-[a-zA-Z]{4})?(-([a-zA-Z]{2}|[0-9]{3}))?(-[a-zA-Z]{5,8})?(-x(-[a-zA-Z0-9]{1,8})+)?$"
           }
         }
       ]

packages/angular_devkit/build_angular/src/utils/i18n-options.ts

@@ -338,10 +338,13 @@ function findLocaleDataBasePath(projectRoot: string): string | null {
 }
 
 function findLocaleDataPath(locale: string, basePath: string): string | null {
-  const localeDataPath = path.join(basePath, locale + '.js');
+  // Remove private use subtags
+  const scrubbedLocale = locale.replace(/-x(-[a-zA-Z0-9]{1,8})+$/, '');
+
+  const localeDataPath = path.join(basePath, scrubbedLocale + '.js');
 
   if (!fs.existsSync(localeDataPath)) {
-    if (locale === 'en-US') {
+    if (scrubbedLocale === 'en-US') {
       // fallback to known existing en-US locale data as of 9.0
       return findLocaleDataPath('en-US-POSIX', basePath);
     }

packages/angular_devkit/core/src/experimental/workspace/workspace-schema.json

@@ -136,7 +136,7 @@
               "type": "string",
               "description": "Specifies the source locale of the application.",
               "default": "en-US",
-              "pattern": "^[a-zA-Z]{2,3}(-[a-zA-Z]{4})?(-([a-zA-Z]{2}|[0-9]{3}))?(-[a-zA-Z]{5,8})?$"
+              "pattern": "^[a-zA-Z]{2,3}(-[a-zA-Z]{4})?(-([a-zA-Z]{2}|[0-9]{3}))?(-[a-zA-Z]{5,8})?(-x(-[a-zA-Z0-9]{1,8})+)?$"
             },
             {
               "type": "object",
@@ -145,7 +145,7 @@
                 "code": {
                   "type": "string",
                   "description": "Specifies the locale code of the source locale",
-                  "pattern": "^[a-zA-Z]{2,3}(-[a-zA-Z]{4})?(-([a-zA-Z]{2}|[0-9]{3}))?(-[a-zA-Z]{5,8})?$"
+                  "pattern": "^[a-zA-Z]{2,3}(-[a-zA-Z]{4})?(-([a-zA-Z]{2}|[0-9]{3}))?(-[a-zA-Z]{5,8})?(-x(-[a-zA-Z0-9]{1,8})+)?$"
                 },
                 "baseHref": {
                   "type": "string",
@@ -160,7 +160,7 @@
           "type": "object",
           "additionalProperties": false,
           "patternProperties": {
-            "^[a-zA-Z]{2,3}(-[a-zA-Z]{4})?(-([a-zA-Z]{2}|[0-9]{3}))?(-[a-zA-Z]{5,8})?$": {
+            "^[a-zA-Z]{2,3}(-[a-zA-Z]{4})?(-([a-zA-Z]{2}|[0-9]{3}))?(-[a-zA-Z]{5,8})?(-x(-[a-zA-Z0-9]{1,8})+)?$": {
               "oneOf": [
                 {
                   "type": "string",

tests/legacy-cli/e2e/tests/i18n/ivy-localize-locale-data.ts

@@ -43,4 +43,18 @@ export default async function() {
     throw new Error('locale data not found warning shown');
   }
 
+  // Update angular.json
+  await updateJsonFile('angular.json', workspaceJson => {
+    const appProject = workspaceJson.projects['test-project'];
+    // tslint:disable-next-line: no-any
+    const i18n: Record<string, any> = appProject.i18n;
+
+    i18n.sourceLocale = 'en-x-abc';
+    appProject.architect['build'].options.localize = ['en-x-abc'];
+  });
+
+  const { stderr: err3 } = await ng('build');
+  if (err3.includes(`Locale data for 'en-x-abc' cannot be found.  No locale data will be included for this locale.`)) {
+    throw new Error('locale data not found warning shown');
+  }
 }