fix(ivy): i18n - support "\", "`" and "${" sequences in i18n messages (#33820)

Since i18n messages are mapped to `$localize` tagged template strings,
the "raw" version must be properly escaped. Otherwise TS will throw an
error such as:

```
Error: Debug Failure. False expression: Expected argument 'text' to be the normalized (i.e. 'cooked') version of argument 'rawText'.
```

This commit ensures that we properly escape these raw strings before creating
TS AST nodes from them.

PR Close #33820

packages/compiler/src/output/abstract_emitter.ts

@@ -7,8 +7,6 @@
  */
 
 import {ParseSourceSpan} from '../parse_util';
-import {serializeI18nHead, serializeI18nTemplatePart} from '../render3/view/i18n/meta';
-
 import * as o from './output_ast';
 import {SourceMapGenerator} from './source_map';
 
@@ -363,14 +361,12 @@ export abstract class AbstractEmitterVisitor implements o.StatementVisitor, o.Ex
   }
 
   visitLocalizedString(ast: o.LocalizedString, ctx: EmitterVisitorContext): any {
-    const head = serializeI18nHead(ast.metaBlock, ast.messageParts[0]);
-    ctx.print(ast, '$localize `' + escapeBackticks(head.raw));
+    const head = ast.serializeI18nHead();
+    ctx.print(ast, '$localize `' + head.raw);
     for (let i = 1; i < ast.messageParts.length; i++) {
       ctx.print(ast, '${');
       ast.expressions[i - 1].visitExpression(this, ctx);
-      ctx.print(
-          ast,
-          `}${escapeBackticks(serializeI18nTemplatePart(ast.placeHolderNames[i - 1], ast.messageParts[i]))}`);
+      ctx.print(ast, `}${ast.serializeI18nTemplatePart(i).raw}`);
     }
     ctx.print(ast, '`');
     return null;
@@ -560,7 +556,3 @@ function _createIndent(count: number): string {
   }
   return res;
 }
-
-function escapeBackticks(str: string): string {
-  return str.replace(/`/g, '\\`');
-}

packages/compiler/src/output/output_ast.ts

@@ -499,8 +499,74 @@ export class LocalizedString extends Expression {
   visitExpression(visitor: ExpressionVisitor, context: any): any {
     return visitor.visitLocalizedString(this, context);
   }
+
+  /**
+   * Serialize the given `meta` and `messagePart` into "cooked" and "raw" strings that can be used
+   * in a `$localize` tagged string. The format of the metadata is the same as that parsed by
+   * `parseI18nMeta()`.
+   *
+   * @param meta The metadata to serialize
+   * @param messagePart The first part of the tagged string
+   */
+  serializeI18nHead(): {cooked: string, raw: string} {
+    let metaBlock = this.metaBlock.description || '';
+    if (this.metaBlock.meaning) {
+      metaBlock = `${this.metaBlock.meaning}|${metaBlock}`;
+    }
+    if (this.metaBlock.customId || this.metaBlock.legacyId) {
+      metaBlock = `${metaBlock}@@${this.metaBlock.customId || this.metaBlock.legacyId}`;
+    }
+    return createCookedRawString(metaBlock, this.messageParts[0]);
+  }
+
+  /**
+   * Serialize the given `placeholderName` and `messagePart` into "cooked" and "raw" strings that
+   * can be used in a `$localize` tagged string.
+   *
+   * @param placeholderName The placeholder name to serialize
+   * @param messagePart The following message string after this placeholder
+   */
+  serializeI18nTemplatePart(partIndex: number): {cooked: string, raw: string} {
+    const placeholderName = this.placeHolderNames[partIndex - 1];
+    const messagePart = this.messageParts[partIndex];
+    return createCookedRawString(placeholderName, messagePart);
+  }
 }
 
+const escapeSlashes = (str: string): string => str.replace(/\\/g, '\\\\');
+const escapeStartingColon = (str: string): string => str.replace(/^:/, '\\:');
+const escapeColons = (str: string): string => str.replace(/:/g, '\\:');
+const escapeForMessagePart = (str: string): string =>
+    str.replace(/`/g, '\\`').replace(/\${/g, '$\\{');
+
+/**
+ * Creates a `{cooked, raw}` object from the `metaBlock` and `messagePart`.
+ *
+ * The `raw` text must have various character sequences escaped:
+ * * "\" would otherwise indicate that the next character is a control character.
+ * * "`" and "${" are template string control sequences that would otherwise prematurely indicate
+ *   the end of a message part.
+ * * ":" inside a metablock would prematurely indicate the end of the metablock.
+ * * ":" at the start of a messagePart with no metablock would erroneously indicate the start of a
+ *   metablock.
+ *
+ * @param metaBlock Any metadata that should be prepended to the string
+ * @param messagePart The message part of the string
+ */
+function createCookedRawString(metaBlock: string, messagePart: string) {
+  if (metaBlock === '') {
+    return {
+      cooked: messagePart,
+      raw: escapeForMessagePart(escapeStartingColon(escapeSlashes(messagePart)))
+    };
+  } else {
+    return {
+      cooked: `:${metaBlock}:${messagePart}`,
+      raw: escapeForMessagePart(
+          `:${escapeColons(escapeSlashes(metaBlock))}:${escapeSlashes(messagePart)}`)
+    };
+  }
+}
 
 export class ExternalExpr extends Expression {
   constructor(

packages/compiler/src/render3/view/i18n/meta.ts

@@ -234,50 +234,6 @@ export function parseI18nMeta(meta?: string): I18nMeta {
   return {customId, meaning, description};
 }
 
-/**
- * Serialize the given `meta` and `messagePart` "cooked" and "raw" strings that can be used in a
- * `$localize` tagged string. The format of the metadata is the same as that parsed by
- * `parseI18nMeta()`.
- *
- * @param meta The metadata to serialize
- * @param messagePart The first part of the tagged string
- */
-export function serializeI18nHead(
-    meta: I18nMeta, messagePart: string): {cooked: string, raw: string} {
-  let metaBlock = meta.description || '';
-  if (meta.meaning) {
-    metaBlock = `${meta.meaning}|${metaBlock}`;
-  }
-  if (meta.customId || meta.legacyId) {
-    metaBlock = `${metaBlock}@@${meta.customId || meta.legacyId}`;
-  }
-  if (metaBlock === '') {
-    // There is no metaBlock, so we must ensure that any starting colon is escaped.
-    return {cooked: messagePart, raw: escapeStartingColon(messagePart)};
-  } else {
-    return {
-      cooked: `:${metaBlock}:${messagePart}`,
-      raw: `:${escapeColons(metaBlock)}:${messagePart}`
-    };
-  }
-}
-
-/**
- * Serialize the given `placeholderName` and `messagePart` into strings that can be used in a
- * `$localize` tagged string.
- *
- * @param placeholderName The placeholder name to serialize
- * @param messagePart The following message string after this placeholder
- */
-export function serializeI18nTemplatePart(placeholderName: string, messagePart: string): string {
-  if (placeholderName === '') {
-    // There is no placeholder name block, so we must ensure that any starting colon is escaped.
-    return escapeStartingColon(messagePart);
-  } else {
-    return `:${placeholderName}:${messagePart}`;
-  }
-}
-
 // Converts i18n meta information for a message (id, description, meaning)
 // to a JsDoc statement formatted as expected by the Closure compiler.
 export function i18nMetaToDocStmt(meta: I18nMeta): o.JSDocCommentStmt|null {
@@ -290,11 +246,3 @@ export function i18nMetaToDocStmt(meta: I18nMeta): o.JSDocCommentStmt|null {
   }
   return tags.length == 0 ? null : new o.JSDocCommentStmt(tags);
 }
-
-export function escapeStartingColon(str: string): string {
-  return str.replace(/^:/, '\\:');
-}
-
-export function escapeColons(str: string): string {
-  return str.replace(/:/g, '\\:');
-}