fix(compiler): lexer support for template literals in object literals (angular#61601)

This commit fixes a shortcoming of the lexer with template literals

fixes angular#61572

PR Close angular#61601

Author: JeanMeche

packages/compiler/src/expression_parser/lexer.ts

@@ -212,8 +212,7 @@ class _Scanner {
   private readonly length: number;
   private peek = 0;
   private index = -1;
-  private literalInterpolationDepth = 0;
-  private braceDepth = 0;
+  private braceStack: ('interpolation' | 'expression')[] = [];
 
   constructor(private readonly input: string) {
     this.length = input.length;
@@ -341,21 +340,20 @@ class _Scanner {
   }
 
   private scanOpenBrace(start: number, code: number): Token {
-    this.braceDepth++;
+    this.braceStack.push('expression');
     this.advance();
     return newCharacterToken(start, this.index, code);
   }
 
   private scanCloseBrace(start: number, code: number): Token {
     this.advance();
 
-    if (this.braceDepth === 0 && this.literalInterpolationDepth > 0) {
-      this.literalInterpolationDepth--;
+    const currentBrace = this.braceStack.pop();
+    if (currentBrace === 'interpolation') {
       this.tokens.push(newOperatorToken(start, this.index, '}'));
       return this.scanTemplateLiteralPart(this.index);
     }
 
-    this.braceDepth--;
     return newCharacterToken(start, this.index, code);
   }
 
@@ -512,7 +510,7 @@ class _Scanner {
 
         // @ts-expect-error
         if (this.peek === chars.$LBRACE) {
-          this.literalInterpolationDepth++;
+          this.braceStack.push('interpolation');
           this.tokens.push(
             new StringToken(
               start,

packages/compiler/test/expression_parser/lexer_spec.ts

@@ -588,6 +588,20 @@ describe('lexer', () => {
         expectStringToken(tokens[8], 29, 33, '!!!', StringTokenKind.TemplateLiteralEnd);
       });
 
+      it('should tokenize a template literal in an literal object value', () => {
+        const tokens: Token[] = lex('{foo: `${name}`}');
+        expect(tokens.length).toBe(9);
+        expectCharacterToken(tokens[0], 0, 1, '{');
+        expectIdentifierToken(tokens[1], 1, 4, 'foo');
+        expectCharacterToken(tokens[2], 4, 5, ':');
+        expectStringToken(tokens[3], 6, 7, '', StringTokenKind.TemplateLiteralPart);
+        expectOperatorToken(tokens[4], 7, 9, '${');
+        expectIdentifierToken(tokens[5], 9, 13, 'name');
+        expectOperatorToken(tokens[6], 13, 14, '}');
+        expectStringToken(tokens[7], 14, 15, '', StringTokenKind.TemplateLiteralEnd);
+        expectCharacterToken(tokens[8], 15, 16, '}');
+      });
+
       it('should produce an error if a template literal is not terminated', () => {
         expectErrorToken(
           lex('`hello')[0],

packages/compiler/test/expression_parser/parser_spec.ts

@@ -453,6 +453,13 @@ describe('parser', () => {
         checkBinding('`hello ${(name | capitalize)}!!!`', '`hello ${((name | capitalize))}!!!`');
       });
 
+      it('should parse template literals in objects literals', () => {
+        checkBinding('{"a": `${name}`}');
+        checkBinding('{"a": `hello ${name}!`}');
+        checkBinding('{"a": `hello ${`hello ${`hello`}`}!`}');
+        checkBinding('{"a": `hello ${{"b": `hello`}}`}');
+      });
+
       it('should report error if interpolation is empty', () => {
         expectBindingError(
           '`hello ${}`',