refactor(localize): add support for TranslationParser diagnostics (#35793)

This modifies the internal (but shared with CLI) API for loading/parsing
translation files. Now the parsers will return a new `Diagnostics` object
along with any translations and locale extracted from the file.

It is up to the caller to decide what to do about this, if there are errors
it is suggested that an error is thrown, which is what the `TranslationLoader`
class does.

PR Close #35793

packages/localize/src/tools/src/diagnostics.ts

@@ -15,4 +15,15 @@ export class Diagnostics {
   get hasErrors() { return this.messages.some(m => m.type === 'error'); }
   warn(message: string) { this.messages.push({type: 'warning', message}); }
   error(message: string) { this.messages.push({type: 'error', message}); }
+  formatDiagnostics(message: string): string {
+    const errors = this.messages !.filter(d => d.type === 'error').map(d => ' - ' + d.message);
+    const warnings = this.messages !.filter(d => d.type === 'warning').map(d => ' - ' + d.message);
+    if (errors.length) {
+      message += '\nERRORS:\n' + errors.join('\n');
+    }
+    if (warnings.length) {
+      message += '\nWARNINGS:\n' + warnings.join('\n');
+    }
+    return message;
+  }
 }

packages/localize/src/tools/src/translate/main.ts

@@ -142,7 +142,7 @@ export function translateFiles({sourceRootPath, sourceFilePaths, translationFile
       [
         new Xliff2TranslationParser(),
         new Xliff1TranslationParser(),
-        new XtbTranslationParser(diagnostics),
+        new XtbTranslationParser(),
         new SimpleJsonTranslationParser(),
       ],
       diagnostics);

packages/localize/src/tools/src/translate/translation_files/translation_loader.ts

@@ -14,7 +14,9 @@ import {TranslationParser} from './translation_parsers/translation_parser';
  * Use this class to load a collection of translation files from disk.
  */
 export class TranslationLoader {
-  constructor(private translationParsers: TranslationParser[], private diagnostics: Diagnostics) {}
+  constructor(
+      private translationParsers: TranslationParser[],
+      /** @deprecated */ private diagnostics?: Diagnostics) {}
 
   /**
    * Load and parse the translation files into a collection of `TranslationBundles`.
@@ -34,22 +36,37 @@ export class TranslationLoader {
     return translationFilePaths.map((filePath, index) => {
       const fileContents = FileUtils.readFile(filePath);
       for (const translationParser of this.translationParsers) {
-        if (translationParser.canParse(filePath, fileContents)) {
+        const result = translationParser.canParse(filePath, fileContents);
-          const providedLocale = translationFileLocales[index];
+        if (!result) {
-          const {locale: parsedLocale, translations} =
+          continue;
-              translationParser.parse(filePath, fileContents);
-          const locale = providedLocale || parsedLocale;
-          if (locale === undefined) {
-            throw new Error(
-                `The translation file "${filePath}" does not contain a target locale and no explicit locale was provided for this file.`);
-          }
-          if (parsedLocale !== undefined && providedLocale !== undefined &&
-              parsedLocale !== providedLocale) {
-            this.diagnostics.warn(
-                `The provided locale "${providedLocale}" does not match the target locale "${parsedLocale}" found in the translation file "${filePath}".`);
-          }
-          return {locale, translations};
         }
+
+        const {locale: parsedLocale, translations, diagnostics} =
+            translationParser.parse(filePath, fileContents);
+        if (diagnostics.hasErrors) {
+          throw new Error(diagnostics.formatDiagnostics(
+              `The translation file "${filePath}" could not be parsed.`));
+        }
+
+        const providedLocale = translationFileLocales[index];
+        const locale = providedLocale || parsedLocale;
+        if (locale === undefined) {
+          throw new Error(
+              `The translation file "${filePath}" does not contain a target locale and no explicit locale was provided for this file.`);
+        }
+
+        if (parsedLocale !== undefined && providedLocale !== undefined &&
+            parsedLocale !== providedLocale) {
+          diagnostics.warn(
+              `The provided locale "${providedLocale}" does not match the target locale "${parsedLocale}" found in the translation file "${filePath}".`);
+        }
+
+        // If we were passed a diagnostics object then copy the messages over to it.
+        if (this.diagnostics) {
+          this.diagnostics.messages.push(...diagnostics.messages);
+        }
+
+        return {locale, translations, diagnostics};
       }
       throw new Error(
           `There is no "TranslationParser" that can parse this translation file: ${filePath}.`);

packages/localize/src/tools/src/translate/translation_files/translation_parsers/simple_json_translation_parser.ts

@@ -7,6 +7,7 @@
  */
 import {ɵMessageId, ɵParsedTranslation, ɵparseTranslation} from '@angular/localize';
 import {extname} from 'path';
+import {Diagnostics} from '../../../diagnostics';
 import {ParsedTranslationBundle, TranslationParser} from './translation_parser';
 
 /**
@@ -32,6 +33,6 @@ export class SimpleJsonTranslationParser implements TranslationParser {
       const targetMessage = translations[messageId];
       parsedTranslations[messageId] = ɵparseTranslation(targetMessage);
     }
-    return {locale: parsedLocale, translations: parsedTranslations};
+    return {locale: parsedLocale, translations: parsedTranslations, diagnostics: new Diagnostics()};
   }
 }

packages/localize/src/tools/src/translate/translation_files/translation_parsers/translation_parser.ts

@@ -6,6 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 import {ɵMessageId, ɵParsedTranslation} from '@angular/localize/private';
+import {Diagnostics} from '../../../diagnostics';
 
 /**
 * An object that holds translations that have been parsed from a translation file.
@@ -13,6 +14,7 @@ import {ɵMessageId, ɵParsedTranslation} from '@angular/localize/private';
 export interface ParsedTranslationBundle {
   locale: string|undefined;
   translations: Record<ɵMessageId, ɵParsedTranslation>;
+  diagnostics: Diagnostics;
 }
 
 /**

packages/localize/src/tools/src/translate/translation_files/translation_parsers/xliff1_translation_parser.ts

@@ -9,6 +9,7 @@ import {Element, Node, XmlParser, visitAll} from '@angular/compiler';
 import {ɵMessageId, ɵParsedTranslation} from '@angular/localize';
 import {extname} from 'path';
 
+import {Diagnostics} from '../../../diagnostics';
 import {BaseVisitor} from '../base_visitor';
 import {MessageSerializer} from '../message_serialization/message_serializer';
 import {TargetMessageRenderer} from '../message_serialization/target_message_renderer';
@@ -55,7 +56,8 @@ class XliffFileElementVisitor extends BaseVisitor {
     if (element.name === 'file') {
       this.bundle = {
         locale: getAttribute(element, 'target-language'),
-        translations: XliffTranslationVisitor.extractTranslations(element)
+        translations: XliffTranslationVisitor.extractTranslations(element),
+        diagnostics: new Diagnostics(),
       };
     } else {
       return visitAll(this, element.children);

packages/localize/src/tools/src/translate/translation_files/translation_parsers/xliff2_translation_parser.ts

@@ -9,6 +9,7 @@ import {Element, Node, XmlParser, visitAll} from '@angular/compiler';
 import {ɵMessageId, ɵParsedTranslation} from '@angular/localize';
 import {extname} from 'path';
 
+import {Diagnostics} from '../../../diagnostics';
 import {BaseVisitor} from '../base_visitor';
 import {MessageSerializer} from '../message_serialization/message_serializer';
 import {TargetMessageRenderer} from '../message_serialization/target_message_renderer';
@@ -61,7 +62,8 @@ class Xliff2TranslationBundleVisitor extends BaseVisitor {
     } else if (element.name === 'file') {
       this.bundle = {
         locale: parsedLocale,
-        translations: Xliff2TranslationVisitor.extractTranslations(element)
+        translations: Xliff2TranslationVisitor.extractTranslations(element),
+        diagnostics: new Diagnostics(),
       };
     } else {
       return visitAll(this, element.children, {parsedLocale});

packages/localize/src/tools/src/translate/translation_files/translation_parsers/xtb_translation_parser.ts

@@ -24,7 +24,7 @@ import {getAttrOrThrow, parseInnerRange} from './translation_utils';
  * A translation parser that can load XB files.
  */
 export class XtbTranslationParser implements TranslationParser {
-  constructor(private diagnostics: Diagnostics) {}
+  constructor(private diagnostics: Diagnostics = new Diagnostics()) {}
 
   canParse(filePath: string, contents: string): boolean {
     const extension = extname(filePath);
@@ -61,7 +61,11 @@ class XtbVisitor extends BaseVisitor {
               element.sourceSpan, '<translationbundle> elements can not be nested');
         }
         const langAttr = element.attrs.find((attr) => attr.name === 'lang');
-        bundle = {locale: langAttr && langAttr.value, translations: {}};
+        bundle = {
+          locale: langAttr && langAttr.value,
+          translations: {},
+          diagnostics: this.diagnostics
+        };
         visitAll(this, element.children, bundle);
         return bundle;
 

packages/localize/src/tools/src/translate/translator.ts

@@ -19,6 +19,7 @@ import {OutputPathFn} from './output_path';
 export interface TranslationBundle {
   locale: string;
   translations: Record<ɵMessageId, ɵParsedTranslation>;
+  diagnostics?: Diagnostics;
 }
 
 /**

packages/localize/src/tools/test/diagnostics_spec.ts

@@ -0,0 +1,48 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+import {Diagnostics} from '../src/diagnostics';
+
+describe('Diagnostics', () => {
+  describe('formatDiagnostics', () => {
+    it('should just return the message passed in if there are no errors nor warnings', () => {
+      const diagnostics = new Diagnostics();
+      expect(diagnostics.formatDiagnostics('This is a message')).toEqual('This is a message');
+    });
+
+    it('should return a string with all the errors listed', () => {
+      const diagnostics = new Diagnostics();
+      diagnostics.error('Error 1');
+      diagnostics.error('Error 2');
+      diagnostics.error('Error 3');
+      expect(diagnostics.formatDiagnostics('This is a message'))
+          .toEqual('This is a message\nERRORS:\n - Error 1\n - Error 2\n - Error 3');
+    });
+
+    it('should return a string with all the warnings listed', () => {
+      const diagnostics = new Diagnostics();
+      diagnostics.warn('Warning 1');
+      diagnostics.warn('Warning 2');
+      diagnostics.warn('Warning 3');
+      expect(diagnostics.formatDiagnostics('This is a message'))
+          .toEqual('This is a message\nWARNINGS:\n - Warning 1\n - Warning 2\n - Warning 3');
+    });
+
+    it('should return a string with all the errors and warnings listed', () => {
+      const diagnostics = new Diagnostics();
+      diagnostics.warn('Warning 1');
+      diagnostics.warn('Warning 2');
+      diagnostics.error('Error 1');
+      diagnostics.error('Error 2');
+      diagnostics.warn('Warning 3');
+      diagnostics.error('Error 3');
+      expect(diagnostics.formatDiagnostics('This is a message'))
+          .toEqual(
+              'This is a message\nERRORS:\n - Error 1\n - Error 2\n - Error 3\nWARNINGS:\n - Warning 1\n - Warning 2\n - Warning 3');
+    });
+  });
+});

packages/localize/src/tools/test/translate/translation_files/translation_loader_spec.ts

@@ -58,8 +58,8 @@ describe('TranslationLoader', () => {
       const result =
           loader.loadBundles(['/src/locale/messages.en.xlf', '/src/locale/messages.fr.xlf'], []);
       expect(result).toEqual([
-        {locale: 'pl', translations},
+        {locale: 'pl', translations, diagnostics: new Diagnostics()},
-        {locale: 'pl', translations},
+        {locale: 'pl', translations, diagnostics: new Diagnostics()},
       ]);
     });
 
@@ -71,8 +71,8 @@ describe('TranslationLoader', () => {
       const result = loader.loadBundles(
           ['/src/locale/messages.en.xlf', '/src/locale/messages.fr.xlf'], ['en', 'fr']);
       expect(result).toEqual([
-        {locale: 'en', translations},
+        {locale: 'en', translations, diagnostics: new Diagnostics()},
-        {locale: 'fr', translations},
+        {locale: 'fr', translations, diagnostics: new Diagnostics()},
       ]);
     });
 
@@ -127,6 +127,6 @@ class MockTranslationParser implements TranslationParser {
 
   parse(filePath: string, fileContents: string) {
     this.log.push(`parse(${filePath}, ${fileContents})`);
-    return {locale: this._locale, translations: this._translations};
+    return {locale: this._locale, translations: this._translations, diagnostics: new Diagnostics()};
   }
 }