[rust-compiler] Add TDD fixtures for TS module-interop statements

compiler/crates/TODO.md

@@ -111,6 +111,46 @@ Each line names the failure mode and a sketch of where to look.
 	`TSTypeParameterInstantiation` in `convert_ast.rs` AND deserialization
 	in `convert_ast_reverse.rs::convert_ts_type_from_json`.
 
+## Cross-frontend: TypeScript module interop statements
+
+Three `todo-ts-*` fixtures pin how TS module-interop statements
+(`import x = require(...)`, `export = x`, `export as namespace X`) must
+behave: the statement is preserved in output and the file's functions
+still compile. The TS reference does both. The three frontends share
+the broken symptom today via three different root causes:
+
+- **Babel/NAPI** throws `Failed to parse AST JSON: unknown variant
+	TSImportEqualsDeclaration` (etc.) because the typed AST's
+	`#[serde(tag = "type")]` enums have no catch-all, failing the whole
+	file. The same root cause reds both `react_compiler_ast` fixture
+	tests (`round_trip` and `scope_resolution_rename`) under
+	`test-babel-ast.sh`.
+- **SWC**'s converter explicitly rewrites all three statements to
+	`EmptyStatement` (`react_compiler_swc/src/convert_ast.rs`,
+	`TsImportEquals` / `TsExportAssignment` / `TsNamespaceExport` arms),
+	erasing them from output with no error and no event.
+- **OXC** `todo!()`-panics in `react_compiler_oxc/src/convert_ast.rs`
+	(arms of the same three names; the sibling `TSGlobalDeclaration` arm
+	is also unmodeled but unreachable from Babel-parsed fixtures, which
+	represent `declare global` as `TSModuleDeclaration`). Deferred.
+
+Known-red until the fixes land: the three fixtures fail Babel and SWC
+e2e and `test-babel-ast.sh`, and the e2e totals elsewhere in this doc
+are stale by +3 fixtures.
+
+Planned fixes: (1) Babel path: unknown-statement tolerance in
+`react_compiler_ast` (untagged catch-all carrying the raw node,
+preserved through codegen and re-serialization); (2) SWC: replace the
+`EmptyStatement` arms with real preservation; mapping unknown nodes to
+`EmptyStatement` is the bug, not a fallback. Rename each fixture to
+drop the `todo-` prefix as it goes green end to end, and update the
+`SproutTodoFilter` entry for the namespace fixture in the same change
+(the filter matches by basename).
+
+- `todo-ts-import-equals-declaration.ts`
+- `todo-ts-export-assignment.ts`
+- `todo-ts-namespace-export-declaration.ts`
+
 ## Babel
 
 **TODO: scope this out.** Babel is at 1788 / 1795 (7 failures). These have

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/todo-ts-export-assignment.expect.md

@@ -0,0 +1,36 @@
+
+## Input
+
+```javascript
+function useValue(value: number) {
+  return [value + 1];
+}
+
+export = useValue;
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime";
+function useValue(value) {
+  const $ = _c(2);
+  const t0 = value + 1;
+  let t1;
+  if ($[0] !== t0) {
+    t1 = [t0];
+    $[0] = t0;
+    $[1] = t1;
+  } else {
+    t1 = $[1];
+  }
+  return t1;
+}
+
+export = useValue;
+
+```
+
+### Eval output
+(kind: exception) Fixture not implemented

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/todo-ts-export-assignment.ts

@@ -0,0 +1,5 @@
+function useValue(value: number) {
+  return [value + 1];
+}
+
+export = useValue;

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/todo-ts-import-equals-declaration.expect.md

@@ -0,0 +1,35 @@
+
+## Input
+
+```javascript
+import lib = require('shared-runtime');
+
+function useValue(value: number) {
+  return lib.identity(value);
+}
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime";
+import lib = require("shared-runtime");
+
+function useValue(value) {
+  const $ = _c(2);
+  let t0;
+  if ($[0] !== value) {
+    t0 = lib.identity(value);
+    $[0] = value;
+    $[1] = t0;
+  } else {
+    t0 = $[1];
+  }
+  return t0;
+}
+
+```
+
+### Eval output
+(kind: exception) Fixture not implemented

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/todo-ts-import-equals-declaration.ts

@@ -0,0 +1,5 @@
+import lib = require('shared-runtime');
+
+function useValue(value: number) {
+  return lib.identity(value);
+}

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/todo-ts-namespace-export-declaration.expect.md

@@ -0,0 +1,33 @@
+
+## Input
+
+```javascript
+export as namespace Foo;
+
+function useValue(value: number) {
+  return {value};
+}
+
+```
+
+## Code
+
+```javascript
+import { c as _c } from "react/compiler-runtime";
+export as namespace Foo;
+
+function useValue(value) {
+  const $ = _c(2);
+  let t0;
+  if ($[0] !== value) {
+    t0 = { value };
+    $[0] = value;
+    $[1] = t0;
+  } else {
+    t0 = $[1];
+  }
+  return t0;
+}
+
+```
+      

compiler/packages/babel-plugin-react-compiler/src/__tests__/fixtures/compiler/todo-ts-namespace-export-declaration.ts

@@ -0,0 +1,5 @@
+export as namespace Foo;
+
+function useValue(value: number) {
+  return {value};
+}

compiler/packages/snap/src/SproutTodoFilter.ts

@@ -17,6 +17,15 @@ const skipFilter = new Set([
   'todo-round3_outlined_naming',
   'todo-round3_promote_used_temps',
 
+  /**
+   * `export as namespace` is a .d.ts-shaped construct; sprout's second-stage
+   * evaluator transform cannot evaluate it. The sibling todo-ts-* interop
+   * fixtures evaluate fine (they transform to CJS) and are deliberately not
+   * skipped. Remove or update this entry when the fixture is renamed after
+   * the Rust fix lands (the filter matches by basename).
+   */
+  'todo-ts-namespace-export-declaration',
+
   /**
    * Observable different in logging between Forget and non-Forget
    */