feat(es/testing): Parse test code as a Program instead of a Module (

#9264)

**Description:**

This PR addresses the issue described in #8713 

**BREAKING CHANGE:**

This will break existing unit tests that use `fold_module`/`visit_module`/`visit_mut_module` if the visitor is intended to work for both modules and scripts, instead of using `fold_program`/`visit_program`/`visit_mut_program`. This will also break existing unit tests if they're testing with input code that gets parsed as a script in `parse_program` if the visitor expects a module (they will need to update their `test!` calls to add `module` as the first argument, or use a function like `apply_module_transform`)

**Related issue:**

 - Closes #8713

.changeset/nine-trees-beam.md

@@ -0,0 +1,5 @@
+---
+swc_ecma_transforms_testing: breaking
+---
+
+feat(es/testing): Parse test code as a `Program` instead of a `Module`

crates/swc_ecma_transforms/tests/decorators.rs

@@ -91,6 +91,7 @@ fn transformation(t: &Tester) -> impl Fold {
 
 // transformation_declaration
 test!(
+    module,
     syntax(false),
     |t| transformation(t),
     transformation_declaration,
@@ -101,6 +102,7 @@ class A {}
 );
 // transformation_initialize_after_super_multiple
 test!(
+    module,
     syntax(false),
     |t| transformation(t),
     transformation_initialize_after_super_multiple,
@@ -134,6 +136,7 @@ export default @dec() class {}
 );
 // transformation_initialize_after_super_statement
 test!(
+    module,
     syntax(false),
     |t| transformation(t),
     transformation_initialize_after_super_statement,
@@ -211,6 +214,7 @@ expect(A).toBe(C);
 );
 // misc_method_name_not_shadow
 test!(
+    module,
     syntax(false),
     |t| tr(t),
     misc_method_name_not_shadow,
@@ -320,6 +324,7 @@ expect(() => {
 );
 // duplicated_keys_computed_keys_same_value
 test!(
+    module,
     syntax(false),
     |t| tr(t),
     duplicated_keys_computed_keys_same_value,
@@ -395,6 +400,7 @@ expect(log).toEqual(numsFrom0to9);
 );
 // transformation_initializer_after_super_bug_8808
 test!(
+    module,
     syntax(false),
     |t| transformation(t),
     transformation_initiailzer_after_super_bug_8808,
@@ -434,6 +440,7 @@ expect(A.prototype.method()).toBe(2);
 );
 // transformation_arguments
 test!(
+    module,
     syntax(false),
     |t| transformation(t),
     transformation_arguments,
@@ -532,6 +539,7 @@ expect(calls).toBe(1);
 // ordering
 // transformation_initialize_after_super_expression
 test!(
+    module,
     syntax(false),
     |t| transformation(t),
     transformation_initialize_after_super_expression,
@@ -903,6 +911,7 @@ expect(Object.getOwnPropertyDescriptor(A.prototype, "foo")).toEqual({
 );
 // transformation_extends
 test!(
+    module,
     syntax(false),
     |t| transformation(t),
     transformation_extends,
@@ -914,6 +923,7 @@ test!(
 // finishers
 // transformation_extends_await
 test!(
+    module,
     syntax(false),
     |t| transformation(t),
     transformation_extends_await,
@@ -926,6 +936,7 @@ async function g() {
 );
 // transformation_extends_yield
 test!(
+    module,
     syntax(false),
     |t| transformation(t),
     transformation_extends_yield,
@@ -1092,6 +1103,7 @@ expect(i).toBe(2);
 );
 // transformation_initialize_after_super_bug_8931
 test!(
+    module,
     syntax(false),
     |t| transformation(t),
     transformation_initialize_after_super_bug_8931,
@@ -1318,6 +1330,7 @@ expect(Foo.prototype.bar).toBe(value2);
 );
 // transformation_expression
 test!(
+    module,
     syntax(false),
     |t| transformation(t),
     transformation_expression,
@@ -1354,6 +1367,7 @@ expect(A.method()).toBe(2);
 // element_descriptors
 // duplicated_keys_computed_keys_same_ast
 test!(
+    module,
     syntax(false),
     |t| tr(t),
     duplicated_keys_computed_keys_same_ast,
@@ -1503,6 +1517,7 @@ expect(desc.set()).toBe(2);
 // misc
 // transformation_extends_exec
 test_exec!(
+    module,
     syntax(false),
     |t| tr(t),
     transformation_extends_exec,
@@ -1549,6 +1564,7 @@ expect(() => {
 );
 // duplicated_keys_computed_keys_same_value_exec
 test_exec!(
+    module,
     syntax(false),
     |t| tr(t),
     duplicated_keys_computed_keys_same_value_exec,
@@ -3882,6 +3898,7 @@ eval: function () {
 );
 
 test!(
+    module,
     ts(),
     |_| decorators(Default::default()),
     issue_846_1,

crates/swc_ecma_transforms_module/tests/amd.rs

@@ -5,7 +5,7 @@ use swc_ecma_parser::{Syntax, TsSyntax};
 use swc_ecma_transforms_base::{feature::FeatureFlag, resolver};
 use swc_ecma_transforms_compat::es2015::for_of;
 use swc_ecma_transforms_module::amd::{self, amd};
-use swc_ecma_transforms_testing::{test, test_fixture};
+use swc_ecma_transforms_testing::{test, test_module_fixture};
 use swc_ecma_transforms_typescript::typescript;
 use swc_ecma_visit::Fold;
 
@@ -60,7 +60,7 @@ fn esm_to_amd(input: PathBuf) {
         Err(..) => Default::default(),
     };
 
-    test_fixture(
+    test_module_fixture(
         if is_ts { ts_syntax() } else { syntax() },
         &|t| tr(config.clone(), is_ts, t.comments.clone()),
         &input,
@@ -70,6 +70,7 @@ fn esm_to_amd(input: PathBuf) {
 }
 
 test!(
+    module,
     syntax(),
     |t| chain!(
         for_of(for_of::Config {

crates/swc_ecma_transforms_module/tests/common_js.rs

@@ -5,7 +5,7 @@ use swc_ecma_parser::{Syntax, TsSyntax};
 use swc_ecma_transforms_base::{feature::FeatureFlag, resolver};
 use swc_ecma_transforms_compat::es2015::for_of;
 use swc_ecma_transforms_module::common_js::{self, common_js};
-use swc_ecma_transforms_testing::{test, test_fixture, FixtureTestConfig};
+use swc_ecma_transforms_testing::{test, test_module_fixture, FixtureTestConfig};
 use swc_ecma_transforms_typescript::typescript;
 use swc_ecma_visit::Fold;
 
@@ -52,7 +52,7 @@ fn esm_to_cjs(input: PathBuf) {
         Err(..) => Default::default(),
     };
 
-    test_fixture(
+    test_module_fixture(
         if is_ts { ts_syntax() } else { syntax() },
         &|_| tr(config.clone(), is_ts),
         &input,
@@ -65,6 +65,7 @@ fn esm_to_cjs(input: PathBuf) {
 }
 
 test!(
+    module,
     syntax(),
     |_| chain!(
         for_of(for_of::Config {

crates/swc_ecma_transforms_module/tests/path_node.rs

@@ -12,7 +12,7 @@ use swc_ecma_transforms_module::{
     path::{ImportResolver, NodeImportResolver},
     rewriter::import_rewriter,
 };
-use swc_ecma_transforms_testing::test_fixture;
+use swc_ecma_transforms_testing::test_module_fixture;
 use testing::run_test2;
 
 type TestProvider = NodeImportResolver<NodeModulesResolver>;
@@ -43,7 +43,7 @@ fn issue_4730() {
     let input_dir = dir.join("input");
     let output_dir = dir.join("output");
 
-    test_fixture(
+    test_module_fixture(
         Syntax::default(),
         &|_| {
             let mut paths = IndexMap::new();
@@ -136,7 +136,7 @@ fn fixture(input_dir: PathBuf) {
         .canonicalize()
         .unwrap();
     dbg!(&base_dir);
-    test_fixture(
+    test_module_fixture(
         Syntax::default(),
         &|_| {
             let rules = config.paths.clone().into_iter().collect();

crates/swc_ecma_transforms_module/tests/system_js.rs

@@ -6,7 +6,7 @@ use swc_common::{chain, Mark};
 use swc_ecma_parser::Syntax;
 use swc_ecma_transforms_base::resolver;
 use swc_ecma_transforms_module::system_js::{system_js, Config};
-use swc_ecma_transforms_testing::{test, test_fixture, Tester};
+use swc_ecma_transforms_testing::{test, test_module_fixture, Tester};
 use swc_ecma_visit::Fold;
 
 fn syntax() -> Syntax {
@@ -23,13 +23,15 @@ fn tr(_tester: &mut Tester<'_>, config: Config) -> impl Fold {
 }
 
 test!(
+    module,
     syntax(),
     |tester| tr(tester, Default::default()),
     allow_continuous_assignment,
     r#"var e = {}; e.a = e.b = e.c = e.d = e.e = e.f = e.g = e.h = e.i = e.j = e.k = e.l = e.m = e.n = e.o = e.p = e.q = e.r = e.s = e.t = e.u = e.v = e.w = e.x = e.y = e.z = e.A = e.B = e.C = e.D = e.E = e.F = e.G = e.H = e.I = e.J = e.K = e.L = e.M = e.N = e.O = e.P = e.Q = e.R = e.S = void 0;"#
 );
 
 test!(
+    module,
     syntax(),
     |tester| tr(
         tester,
@@ -43,6 +45,7 @@ test!(
 );
 
 test!(
+    module,
     syntax(),
     |tester| tr(
         tester,
@@ -60,6 +63,7 @@ test!(
 );
 
 test!(
+    module,
     syntax(),
     |tester| tr(
         tester,
@@ -82,6 +86,7 @@ test!(
 );
 
 test!(
+    module,
     syntax(),
     |tester| tr(
         tester,
@@ -99,6 +104,7 @@ test!(
 );
 
 test!(
+    module,
     syntax(),
     |tester| tr(tester, Default::default()),
     imports,
@@ -117,7 +123,7 @@ fn fixture(input: PathBuf) {
 
     let output = dir.join("output.mjs");
 
-    test_fixture(
+    test_module_fixture(
         syntax(),
         &|tester| tr(tester, Default::default()),
         &input,

crates/swc_ecma_transforms_module/tests/umd.rs

@@ -4,7 +4,7 @@ use swc_common::{chain, Mark};
 use swc_ecma_parser::{Syntax, TsSyntax};
 use swc_ecma_transforms_base::{feature::FeatureFlag, resolver};
 use swc_ecma_transforms_module::umd::{umd, Config};
-use swc_ecma_transforms_testing::{test_fixture, Tester};
+use swc_ecma_transforms_testing::{test_module_fixture, Tester};
 use swc_ecma_transforms_typescript::typescript;
 use swc_ecma_visit::Fold;
 
@@ -58,7 +58,7 @@ fn esm_to_umd(input: PathBuf) {
         Err(..) => Default::default(),
     };
 
-    test_fixture(
+    test_module_fixture(
         if is_ts { ts_syntax() } else { syntax() },
         &|tester| tr(tester, config.clone(), is_ts),
         &input,

crates/swc_ecma_transforms_optimization/src/inline_globals.rs

@@ -202,7 +202,7 @@ impl VisitMut for InlineGlobals {
 #[cfg(test)]
 mod tests {
     use swc_ecma_transforms_testing::{test, Tester};
-    use swc_ecma_utils::DropSpan;
+    use swc_ecma_utils::{DropSpan, StmtOrModuleItem};
 
     use super::*;
 
@@ -220,17 +220,22 @@ mod tests {
                 (*v).into()
             };
 
-            let mut v = tester
+            let v = tester
                 .apply_transform(
                     as_folder(DropSpan),
                     "global.js",
                     ::swc_ecma_parser::Syntax::default(),
                     &v,
                 )
                 .unwrap();
-            assert_eq!(v.body.len(), 1);
-            let v = match v.body.pop().unwrap() {
-                ModuleItem::Stmt(Stmt::Expr(ExprStmt { expr, .. })) => *expr,
+
+            let v = match v {
+                Program::Module(mut m) => m.body.pop().and_then(|x| x.into_stmt().ok()),
+                Program::Script(mut s) => s.body.pop(),
+            };
+            assert!(v.is_some());
+            let v = match v.unwrap() {
+                Stmt::Expr(ExprStmt { expr, .. }) => *expr,
                 _ => unreachable!(),
             };
 

crates/swc_ecma_transforms_optimization/src/simplify/inlining/mod.rs

@@ -468,19 +468,19 @@ impl VisitMut for Inlining<'_> {
         self.visit_with_child(ScopeKind::Cond, &mut stmt.alt);
     }
 
-    fn visit_mut_module_items(&mut self, items: &mut Vec<ModuleItem>) {
+    fn visit_mut_program(&mut self, program: &mut Program) {
         let _tracing = span!(Level::ERROR, "inlining", pass = self.pass).entered();
 
         let old_phase = self.phase;
 
         self.phase = Phase::Analysis;
-        items.visit_mut_children_with(self);
+        program.visit_mut_children_with(self);
 
         tracing::trace!("Switching to Inlining phase");
 
         // Inline
         self.phase = Phase::Inlining;
-        items.visit_mut_children_with(self);
+        program.visit_mut_children_with(self);
 
         self.phase = old_phase;
     }

crates/swc_ecma_transforms_proposal/tests/decorator_evanw.rs

@@ -2,7 +2,7 @@ use std::{fs, path::PathBuf};
 
 use swc_ecma_parser::{EsSyntax, Syntax};
 use swc_ecma_transforms_proposal::decorator_2022_03::decorator_2022_03;
-use swc_ecma_transforms_testing::exec_tr;
+use swc_ecma_transforms_testing::exec_module_tr;
 use swc_ecma_visit::as_folder;
 
 const HELPERS: &str = r###"
@@ -57,7 +57,7 @@ fn fixture(input: PathBuf) {
     {code}"
     );
 
-    exec_tr(
+    exec_module_tr(
         &input.file_name().unwrap().to_string_lossy(),
         Syntax::Es(EsSyntax {
             decorators: true,