Refactor with AstVisitor

Author: fisker

src/transform-ast.ts

@@ -0,0 +1,83 @@
+import * as angular from '@angular/compiler';
+
+import { Source } from './source.ts';
+import { transformVisitor } from './transform-visitor.ts';
+import type { NGEmptyExpression, NGNode, RawNGSpan } from './types.ts';
+
+class Transformer extends Source {
+  node: angular.AST;
+  ancestors: angular.AST[];
+
+  constructor({
+    node,
+    text,
+    ancestors,
+  }: {
+    node: angular.AST;
+    text: string;
+    ancestors: angular.AST[];
+  }) {
+    super(text);
+    this.node = node;
+    this.ancestors = ancestors;
+  }
+
+  create<T extends NGNode>(
+    properties: Partial<T> & { type: T['type'] },
+    location: angular.AST | RawNGSpan | [number, number],
+    ancestors: angular.AST[],
+  ) {
+    const node = super.createNode(properties, location);
+
+    if (ancestors[0] instanceof angular.ParenthesizedExpression) {
+      node.extra = {
+        ...node.extra,
+        parenthesized: true,
+      };
+    }
+
+    return node;
+  }
+
+  createNode<T extends NGNode>(
+    properties: Partial<T> & { type: T['type'] },
+    location: angular.AST | RawNGSpan | [number, number] = this.node,
+    ancestorsToCreate: angular.AST[] = this.ancestors,
+  ) {
+    return this.create(properties, location, ancestorsToCreate);
+  }
+
+  transformChild<T extends NGNode>(child: angular.AST) {
+    return new Transformer({
+      node: child,
+      ancestors: [this.node, ...this.ancestors],
+      text: this.text,
+    }).transform<T>();
+  }
+
+  transformChildren<T extends NGNode>(children: angular.AST[]) {
+    return children.map((child) => this.transformChild<T>(child));
+  }
+
+  transform<T extends NGNode = NGNode>() {
+    const { node } = this;
+    if (node instanceof angular.EmptyExpr) {
+      return this.createNode<NGEmptyExpression>(
+        { type: 'NGEmptyExpression' },
+        node.sourceSpan,
+      ) as T;
+    }
+
+    return node.visit(transformVisitor, this) as T;
+  }
+
+  static transform(node: angular.AST, text: string) {
+    return new Transformer({ node, text, ancestors: [] }).transform();
+  }
+}
+
+const transform = (node: angular.AST, text: string) => {
+  return Transformer.transform(node, text);
+};
+
+export { transform, Transformer };