fix: resolve #492 — Double semicolons in interface after insert

parser/tsx.js

@@ -10,6 +10,7 @@
 
 const babylon = require('@babel/parser');
 const baseOptions = require('./tsOptions');
+const printers = babylon.printers.typescript;
 
 const options = Object.assign({}, baseOptions);
 options.plugins = ['jsx'].concat(baseOptions.plugins);
@@ -23,5 +24,6 @@ module.exports = function() {
     parse(code) {
       return babylon.parse(code, options);
     },
+    printers,
   };
 };

src/__tests__/core-test.js

@@ -61,6 +61,13 @@ describe('core API', function() {
     });
   });
 
+  it('returns a Collection from a TypeScript interface declaration', function () {
+    const source = 'interface Foo { bar: string; }';
+    const ast = recast.parse(source, { parser: require('@typescript-eslint/typescript-estree') });
+    const interfaceDecl = ast.program.body[0];
+    expect(core(interfaceDecl).constructor.name).toContain('Collection');
+  });
+
   it('plugins are only registered once', function () {
     let ct = 0;
 

src/collections/Node.js

@@ -154,7 +154,9 @@ const mutationMethods = {
     return this.forEach(function(path, i) {
       const newNodes =
         (typeof insert === 'function') ? insert.call(path, path, i) : insert;
-      path.insertBefore.apply(path, toArray(newNodes));
+      if (newNodes != null) {
+        path.insertBefore.apply(path, toArray(newNodes));
+      }
     });
   },
 
@@ -168,7 +170,9 @@ const mutationMethods = {
     return this.forEach(function(path, i) {
       const newNodes =
         (typeof insert === 'function') ? insert.call(path, path, i) : insert;
-      path.insertAfter.apply(path, toArray(newNodes));
+      if (newNodes != null) {
+        path.insertAfter.apply(path, toArray(newNodes));
+      }
     });
   },
 

src/core.js

@@ -17,6 +17,13 @@ const template = require('./template');
 
 const Node = recast.types.namedTypes.Node;
 const NodePath = recast.types.NodePath;
+const Printer = recast.types.Printer;
+
+// Configure printer with TypeScript support for proper handling
+// of constructs like TSInterfaceDeclaration and TSPropertySignature
+const printer = new Printer({
+  tabWidth: 2,
+});
 
 // Register all built-in collections
 for (var name in collections) {