feat(semantic): add "unambiguous" SourceType

crates/oxc_semantic/src/builder.rs

@@ -219,6 +219,15 @@ impl<'a> SemanticBuilder<'a> {
             let scope_id = self.scope.add_scope(None, AstNodeId::DUMMY, ScopeFlags::Top);
             program.scope_id.set(Some(scope_id));
         } else {
+            // Upgrade "script" to "module`.
+            if self.source_type.is_unambiguous() {
+                self.source_type = if program.body.iter().any(Statement::is_module_declaration) {
+                    self.source_type.with_module(true)
+                } else {
+                    self.source_type.with_script(true)
+                }
+            }
+
             // Count the number of nodes, scopes, symbols, and references.
             // Use these counts to reserve sufficient capacity in `AstNodes`, `ScopeTree`
             // and `SymbolTable` to store them.

crates/oxc_semantic/src/checker/javascript.rs

@@ -404,6 +404,7 @@ pub fn check_module_declaration<'a>(
     let start = decl.span().start;
     let span = Span::new(start, start + 6);
     match ctx.source_type.module_kind() {
+        ModuleKind::Unambiguous => {}
         ModuleKind::Script => {
             ctx.error(module_code(text, span));
         }

crates/oxc_span/src/source_type/mod.rs

@@ -162,6 +162,10 @@ impl SourceType {
         self.module_kind == ModuleKind::Module
     }
 
+    pub fn is_unambiguous(self) -> bool {
+        self.module_kind == ModuleKind::Unambiguous
+    }
+
     pub fn module_kind(self) -> ModuleKind {
         self.module_kind
     }
@@ -211,6 +215,14 @@ impl SourceType {
         self
     }
 
+    #[must_use]
+    pub const fn with_unambiguous(mut self, yes: bool) -> Self {
+        if yes {
+            self.module_kind = ModuleKind::Unambiguous;
+        }
+        self
+    }
+
     #[must_use]
     pub const fn with_typescript(mut self, yes: bool) -> Self {
         if yes {

crates/oxc_span/src/source_type/types.rs

@@ -3,7 +3,7 @@
 
 use oxc_ast_macros::ast;
 #[cfg(feature = "serialize")]
-use ::{serde::Serialize, tsify::Tsify};
+use {serde::Serialize, tsify::Tsify};
 
 /// Source Type for JavaScript vs TypeScript / Script vs Module / JSX
 #[ast]
@@ -48,6 +48,8 @@ pub enum ModuleKind {
     Script = 0,
     /// ES6 Module
     Module = 1,
+    /// Unambiguous
+    Unambiguous = 2,
 }
 
 /// JSX for JavaScript and TypeScript

crates/oxc_transformer/src/options/babel.rs

@@ -102,7 +102,11 @@ impl BabelOptions {
     }
 
     pub fn is_module(&self) -> bool {
-        self.source_type.as_ref().map_or(false, |s| matches!(s.as_str(), "module" | "unambiguous"))
+        self.source_type.as_ref().map_or(false, |s| s.as_str() == "module")
+    }
+
+    pub fn is_unambiguous(&self) -> bool {
+        self.source_type.as_ref().map_or(false, |s| s.as_str() == "unambiguous")
     }
 
     /// Returns

tasks/coverage/codegen_misc.snap

@@ -1,3 +1,3 @@
 codegen_misc Summary:
-AST Parsed     : 27/27 (100.00%)
-Positive Passed: 27/27 (100.00%)
+AST Parsed     : 29/29 (100.00%)
+Positive Passed: 29/29 (100.00%)

tasks/coverage/misc/pass/babel-16776-m.js

@@ -0,0 +1,5 @@
+await /x.y/g;
+
+export { }
+
+var x, g;

tasks/coverage/misc/pass/babel-16776-s.js

@@ -0,0 +1,3 @@
+await /x.y/g;
+
+var x, g;

tasks/coverage/parser_babel.snap

@@ -2,7 +2,7 @@ commit: 3bcfee23
 
 parser_babel Summary:
 AST Parsed     : 2093/2101 (99.62%)
-Positive Passed: 2083/2101 (99.14%)
+Positive Passed: 2082/2101 (99.10%)
 Negative Passed: 1382/1493 (92.57%)
 Expect Syntax Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/annex-b/enabled/3.1-sloppy-labeled-functions-if-body/input.js
 Expect Syntax Error: tasks/coverage/babel/packages/babel-parser/test/fixtures/core/categorized/invalid-fn-decl-labeled-inside-if/input.js
@@ -132,6 +132,14 @@ Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/core/o
    ·                 ──────────
    ╰────
   help: new.target is only allowed in constructors and functions invoked using thew `new` operator
+Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/core/sourcetype-unambiguous/import-meta/input.js
+
+  × Unexpected import.meta expression
+   ╭─[babel/packages/babel-parser/test/fixtures/core/sourcetype-unambiguous/import-meta/input.js:1:13]
+ 1 │ console.log(import.meta);
+   ·             ───────────
+   ╰────
+  help: import.meta is only allowed in module code
 Expect to Parse: tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/arrow-function/generic-tsx-babel-7/input.ts
 
   × Expected `<` but found `EOF`

tasks/coverage/parser_misc.snap

@@ -1,6 +1,6 @@
 parser_misc Summary:
-AST Parsed     : 27/27 (100.00%)
-Positive Passed: 27/27 (100.00%)
+AST Parsed     : 29/29 (100.00%)
+Positive Passed: 29/29 (100.00%)
 Negative Passed: 17/17 (100.00%)
 
   × Unexpected token

tasks/coverage/semantic_babel.snap

@@ -2,7 +2,7 @@ commit: 3bcfee23
 
 semantic_babel Summary:
 AST Parsed     : 2101/2101 (100.00%)
-Positive Passed: 1736/2101 (82.63%)
+Positive Passed: 1735/2101 (82.58%)
 tasks/coverage/babel/packages/babel-parser/test/fixtures/annex-b/enabled/3.3-function-in-if-body/input.js
 semantic error: Scope children mismatch:
 after transform: ScopeId(0): [ScopeId(1), ScopeId(2)]
@@ -27,6 +27,9 @@ semantic error: Scope children mismatch:
 after transform: ScopeId(3): [ScopeId(4)]
 rebuilt        : ScopeId(3): [ScopeId(4)]
 
+tasks/coverage/babel/packages/babel-parser/test/fixtures/core/sourcetype-unambiguous/import-meta/input.js
+semantic error: Unexpected import.meta expression
+
 tasks/coverage/babel/packages/babel-parser/test/fixtures/core/uncategorised/230/input.js
 semantic error: Binding symbols mismatch:
 after transform: ScopeId(0): [SymbolId(0)]
@@ -769,8 +772,9 @@ semantic error: `export = <value>;` is only supported when compiling modules to
 Please consider using `export default <value>;`, or add @babel/plugin-transform-modules-commonjs to your Babel config.
 
 tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/export/equals-in-unambiguous/input.ts
-semantic error: `export = <value>;` is only supported when compiling modules to CommonJS.
-Please consider using `export default <value>;`, or add @babel/plugin-transform-modules-commonjs to your Babel config.
+semantic error: Unresolved references mismatch:
+after transform: ["f"]
+rebuilt        : []
 
 tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/export/export-type/input.ts
 semantic error: Bindings mismatch:
@@ -894,8 +898,14 @@ semantic error: `import lib = require(...);` is only supported when compiling mo
 Please consider using `import lib from '...';` alongside Typescript's --allowSyntheticDefaultImports option, or add @babel/plugin-transform-modules-commonjs to your Babel config.
 
 tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/import/equals-require-in-unambiguous/input.ts
-semantic error: `import lib = require(...);` is only supported when compiling modules to CommonJS.
-Please consider using `import lib from '...';` alongside Typescript's --allowSyntheticDefaultImports option, or add @babel/plugin-transform-modules-commonjs to your Babel config.
+semantic error: Missing SymbolId: a
+Missing ReferenceId: require
+Binding symbols mismatch:
+after transform: ScopeId(0): [SymbolId(0)]
+rebuilt        : ScopeId(0): [SymbolId(0)]
+Unresolved references mismatch:
+after transform: []
+rebuilt        : ["require"]
 
 tasks/coverage/babel/packages/babel-parser/test/fixtures/typescript/import/export-import/input.ts
 semantic error: Missing SymbolId: A

tasks/coverage/semantic_misc.snap

@@ -1,6 +1,11 @@
 semantic_misc Summary:
-AST Parsed     : 27/27 (100.00%)
-Positive Passed: 15/27 (55.56%)
+AST Parsed     : 29/29 (100.00%)
+Positive Passed: 16/29 (55.17%)
+tasks/coverage/misc/pass/babel-16776-m.js
+semantic error: Symbol flags mismatch:
+after transform: SymbolId(0): SymbolFlags(FunctionScopedVariable | Export)
+rebuilt        : SymbolId(0): SymbolFlags(FunctionScopedVariable)
+
 tasks/coverage/misc/pass/oxc-1288.ts
 semantic error: Bindings mismatch:
 after transform: ScopeId(0): ["from"]