feat: support Angular 20 (#326)

Author: fisker

package.json

@@ -27,7 +27,7 @@
     "release": "yarn build && standard-version"
   },
   "devDependencies": {
-    "@angular/compiler": "19.2.2",
+    "@angular/compiler": "20.0.0-next.8",
     "@babel/code-frame": "7.26.2",
     "@babel/parser": "7.26.10",
     "@babel/types": "7.26.10",
@@ -50,7 +50,7 @@
     "vitest": "3.0.8"
   },
   "peerDependencies": {
-    "@angular/compiler": ">=19.2.2"
+    "@angular/compiler": ">=19.2.2 || ^20.0.0"
   },
   "engines": {
     "node": ">= 20"

src/transform-node.ts

@@ -126,7 +126,7 @@ class Transformer extends Source {
     if (node instanceof angular.Interpolation) {
       const { expressions } = node;
 
-      // istanbul ignore next 3
+      /* c8 ignore next 3 */
       if (expressions.length !== 1) {
         throw new Error("Unexpected 'Interpolation'");
       }
@@ -373,7 +373,7 @@ class Transformer extends Source {
             { type: 'Identifier', name: 'undefined', ...node.sourceSpan },
             { hasParentParens: isInParentParens },
           );
-        // istanbul ignore next
+        /* c8 ignore next 4 */
         default:
           throw new Error(
             `Unexpected LiteralPrimitive value type ${typeof value}`,
@@ -427,20 +427,35 @@ class Transformer extends Source {
       );
     }
 
-    const isPrefixNot = node instanceof angular.PrefixNot;
-    if (isPrefixNot || node instanceof angular.TypeofExpression) {
-      const expression = this.#transform<babel.Expression>(node.expression);
+    if (
+      node instanceof angular.PrefixNot ||
+      node instanceof angular.TypeofExpression ||
+      node instanceof angular.VoidExpression
+    ) {
+      const operator =
+        node instanceof angular.PrefixNot
+          ? '!'
+          : node instanceof angular.TypeofExpression
+            ? 'typeof'
+            : node instanceof angular.VoidExpression
+              ? 'void'
+              : /* c8 ignore next */
+                undefined;
+
+      /* c8 ignore next 3 */
+      if (!operator) {
+        throw new Error('Unexpected expression.');
+      }
 
-      const operator = isPrefixNot ? '!' : 'typeof';
       let { start } = node.sourceSpan;
 
-      if (!isPrefixNot) {
+      if (operator === 'typeof' || operator === 'void') {
         const index = this.text.lastIndexOf(operator, start);
 
-        // istanbul ignore next 7
+        /* c8 ignore next 7 */
         if (index === -1) {
           throw new Error(
-            `Cannot find operator ${operator} from index ${start} in ${JSON.stringify(
+            `Cannot find operator '${operator}' from index ${start} in ${JSON.stringify(
               this.text,
             )}`,
           );
@@ -449,6 +464,8 @@ class Transformer extends Source {
         start = index;
       }
 
+      const expression = this.#transform<babel.Expression>(node.expression);
+
       return this.#create<babel.UnaryExpression>(
         {
           type: 'UnaryExpression',
@@ -539,6 +556,15 @@ class Transformer extends Source {
       );
     }
 
+    if (node instanceof angular.TaggedTemplateLiteral) {
+      return this.#create<babel.TaggedTemplateExpression>({
+        type: 'TaggedTemplateExpression',
+        tag: this.#transform(node.tag) as babel.Expression,
+        quasi: this.#transform(node.template) as babel.TemplateLiteral,
+        ...node.sourceSpan,
+      });
+    }
+
     if (node instanceof angular.TemplateLiteral) {
       const { elements, expressions } = node;
 
@@ -579,7 +605,11 @@ class Transformer extends Source {
       );
     }
 
-    // istanbul ignore next
+    if (node instanceof angular.ParenthesizedExpression) {
+      return this.#transformNode(node.expression);
+    }
+
+    /* c8 ignore next */
     throw new Error(`Unexpected node type '${node.constructor.name}'`);
   }
 }
@@ -608,7 +638,10 @@ type SupportedNodes =
   | angular.EmptyExpr
   | angular.PrefixNot
   | angular.TypeofExpression
-  | angular.TemplateLiteral; // Including `TemplateLiteralElement`
+  | angular.VoidExpression
+  | angular.TemplateLiteral // Including `TemplateLiteralElement`
+  | angular.TaggedTemplateLiteral
+  | angular.ParenthesizedExpression;
 function transform(node: SupportedNodes, text: string): NGNode {
   return new Transformer(node, text).node;
 }

src/transform-template-binding.ts

@@ -168,13 +168,14 @@ class Transformer extends NodeTransformer {
         });
 
         const lastNode = body.pop()!;
-        // istanbul ignore else
+
         if (lastNode.type === 'NGMicrosyntaxExpression') {
           body.push(updateExpressionAlias(lastNode));
         } else if (lastNode.type === 'NGMicrosyntaxKeyedExpression') {
           const expression = updateExpressionAlias(lastNode.expression);
           body.push(updateSpanEnd({ ...lastNode, expression }, expression.end));
         } else {
+          /* c8 ignore next 2 */
           throw new Error(`Unexpected type ${lastNode.type}`);
         }
       } else {

src/utils.ts

@@ -106,6 +106,7 @@ export function getCharacterLastIndex(
     }
   }
 
+  /* c8 ignore next 4 */
   throw new Error(
     `Cannot find front char ${pattern} from index ${fromIndex} in ${JSON.stringify(
       text,

tests/helpers.ts

@@ -169,9 +169,17 @@ const KNOWN_AST_TYPES = [
   'SafePropertyRead',
   'ThisReceiver',
   'Interpolation',
+  'VoidExpression',
+  'TemplateLiteral',
+  'TaggedTemplateLiteral',
+  'ParenthesizedExpression',
 ] as const;
 
 export function getAngularNodeType(node: angular.AST) {
+  if (node instanceof angular.ParenthesizedExpression) {
+    return getAngularNodeType(node.expression);
+  }
+
   return (
     KNOWN_AST_TYPES.find((type) => node instanceof angular[type]) ??
     node.constructor.name