fix: handle TsTypeAssertion that conflicts with JSX handling for tarball bundling

packages/edge-bundler/node/utils/import_attributes.test.ts

@@ -153,6 +153,30 @@ import data2 from './data.json' with { type: 'json' };
     expect(result).toEqual(expectedResult)
   })
 
+  test('handles TsTypeAssertion despite no support in acorn-walk', () => {
+    // edge case, because "<Params> inputs" is valid JSX syntax (a component with name "Params" and children "inputs"),
+    // but also valid TypeScript syntax (type assertion). In this case, the acorn-jsx parser will parse it as JSX,
+    // but then throw an error when it encounters the "assert" keyword in the import assertion.
+    // We want to make sure we can handle this case and still rewrite the import assertions correctly.
+    const source = `
+import data3 from './data.json' assert { type: 'json' };
+const params = <Params> inputs;
+const [,foo]=[1,2]
+import data2 from './data.json' assert { type: 'json' };
+`
+    const expectedResult = `
+import data3 from './data.json' with { type: 'json' };
+const params = <Params> inputs;
+const [,foo]=[1,2]
+import data2 from './data.json' with { type: 'json' };
+`
+
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment, @typescript-eslint/no-unsafe-call
+    const result = rewriteSourceImportAssertions(source)
+
+    expect(result).toEqual(expectedResult)
+  })
+
   test('complex JSX import assertion case', () => {
     const source = `<><Component prop={() => import('./foo.json', { assert: { type: 'json' } })} /></>`
     const expectedResult = `<><Component prop={() => import('./foo.json', { with: { type: 'json' } })} /></>`

packages/edge-bundler/node/utils/import_attributes.ts

@@ -1,8 +1,35 @@
 import { Parser, Node } from 'acorn'
-import type { ExportAllDeclaration, ExportNamedDeclaration, ImportDeclaration, ImportExpression } from 'acorn'
+import type {
+  ExportAllDeclaration,
+  ExportNamedDeclaration,
+  ImportDeclaration,
+  ImportExpression,
+  Options as AcornOptions,
+  Program,
+} from 'acorn'
 import { tsPlugin } from '@sveltejs/acorn-typescript'
 
-const acorn = Parser.extend(tsPlugin({ jsx: true }))
+const acornNoJSX = Parser.extend(tsPlugin({ jsx: false }))
+const acornJSX = Parser.extend(tsPlugin({ jsx: true }))
+
+const parseOptions: AcornOptions = {
+  ecmaVersion: 'latest',
+  sourceType: 'module',
+  locations: true,
+}
+
+const parseAST = (source: string): Program => {
+  try {
+    return acornJSX.parse(source, parseOptions)
+  } catch (error) {
+    // for non-jsx typescript casting to type via "<type> value" (normally done with "value as type") will throw an "Unexpected token" error in acorn-jsx,
+    // but is valid syntax in TypeScript. In this case, we can retry parsing with the non-jsx parser.
+    if (error instanceof SyntaxError) {
+      return acornNoJSX.parse(source, parseOptions)
+    }
+    throw error
+  }
+}
 
 /**
  * Given source code rewrites import assert into import with
@@ -15,11 +42,7 @@ export function rewriteSourceImportAssertions(source: string): string {
   let modified = source
 
   try {
-    const parsedAST = acorn.parse(source, {
-      ecmaVersion: 'latest',
-      sourceType: 'module',
-      locations: true,
-    })
+    const parsedAST = parseAST(source)
 
     const statements = collectImportAssertions(source, parsedAST.body)