feat(isolated_declarations): add stripInternal

crates/oxc_isolated_declarations/examples/isolated_declarations.rs

@@ -3,7 +3,7 @@ use std::{env, path::Path};
 
 use oxc_allocator::Allocator;
 use oxc_codegen::{CodeGenerator, CommentOptions};
-use oxc_isolated_declarations::IsolatedDeclarations;
+use oxc_isolated_declarations::{IsolatedDeclarations, IsolatedDeclarationsOptions};
 use oxc_parser::Parser;
 use oxc_span::SourceType;
 
@@ -32,7 +32,13 @@ fn main() {
     println!("Original:\n");
     println!("{source_text}\n");
 
-    let id_ret = IsolatedDeclarations::new(&allocator).build(&ret.program);
+    let id_ret = IsolatedDeclarations::new(
+        &allocator,
+        &source_text,
+        &ret.trivias,
+        IsolatedDeclarationsOptions { strip_internal: true },
+    )
+    .build(&ret.program);
     let printed = CodeGenerator::new()
         .enable_comment(
             &source_text,

crates/oxc_isolated_declarations/src/class.rs

@@ -359,6 +359,10 @@ impl<'a> IsolatedDeclarations<'a> {
             match element {
                 ClassElement::StaticBlock(_) => {}
                 ClassElement::MethodDefinition(ref method) => {
+                    if self.has_internal_annotation(method.span) {
+                        continue;
+                    }
+
                     if !(method.r#type.is_abstract() || method.optional)
                         && method.value.body.is_none()
                     {
@@ -439,6 +443,10 @@ impl<'a> IsolatedDeclarations<'a> {
                     elements.push(new_element);
                 }
                 ClassElement::PropertyDefinition(property) => {
+                    if self.has_internal_annotation(property.span) {
+                        continue;
+                    }
+
                     if self.report_property_key(&property.key, property.computed) {
                         continue;
                     }
@@ -450,6 +458,10 @@ impl<'a> IsolatedDeclarations<'a> {
                     }
                 }
                 ClassElement::AccessorProperty(property) => {
+                    if self.has_internal_annotation(property.span) {
+                        continue;
+                    }
+
                     if self.report_property_key(&property.key, property.computed) {
                         return None;
                     }
@@ -476,7 +488,10 @@ impl<'a> IsolatedDeclarations<'a> {
                     );
                     elements.push(new_element);
                 }
-                ClassElement::TSIndexSignature(_) => elements.push({
+                ClassElement::TSIndexSignature(signature) => elements.push({
+                    if self.has_internal_annotation(signature.span) {
+                        continue;
+                    }
                     // SAFETY: `ast.copy` is unsound! We need to fix.
                     unsafe { self.ast.copy(element) }
                 }),

crates/oxc_isolated_declarations/src/lib.rs

@@ -24,29 +24,56 @@ use std::{cell::RefCell, collections::VecDeque, mem};
 use diagnostics::function_with_assigning_properties;
 use oxc_allocator::Allocator;
 #[allow(clippy::wildcard_imports)]
-use oxc_ast::{ast::*, AstBuilder, Visit, NONE};
+use oxc_ast::{ast::*, AstBuilder, Trivias, Visit, NONE};
 use oxc_diagnostics::OxcDiagnostic;
-use oxc_span::{Atom, SourceType, SPAN};
+use oxc_span::{Atom, GetSpan, SourceType, SPAN};
 use rustc_hash::{FxHashMap, FxHashSet};
 
 use crate::scope::ScopeTree;
 
+#[derive(Debug, Clone, Copy)]
+pub struct IsolatedDeclarationsOptions {
+    /// Do not emit declarations for code that has an @internal annotation in its JSDoc comment.
+    /// This is an internal compiler option; use at your own risk, because the compiler does not check that the result is valid.
+    /// <https://www.typescriptlang.org/tsconfig/#stripInternal>
+    pub strip_internal: bool,
+}
+
 pub struct IsolatedDeclarationsReturn<'a> {
     pub program: Program<'a>,
     pub errors: Vec<OxcDiagnostic>,
 }
 
 pub struct IsolatedDeclarations<'a> {
     ast: AstBuilder<'a>,
+
     // state
     scope: ScopeTree<'a>,
     errors: RefCell<Vec<OxcDiagnostic>>,
+
+    // options
+    strip_internal: bool,
+
+    /// Start position of `@internal` jsdoc annotations.
+    internal_annotations: FxHashSet<u32>,
 }
 
 impl<'a> IsolatedDeclarations<'a> {
-    pub fn new(allocator: &'a Allocator) -> Self {
+    pub fn new(
+        allocator: &'a Allocator,
+        source_text: &str,
+        trivias: &Trivias,
+        options: IsolatedDeclarationsOptions,
+    ) -> Self {
+        let strip_internal = options.strip_internal;
+        let is_internal_set = strip_internal
+            .then(|| Self::build_internal_annotations(source_text, trivias))
+            .unwrap_or_default();
+
         Self {
             ast: AstBuilder::new(allocator),
+            strip_internal,
+            internal_annotations: is_internal_set,
             scope: ScopeTree::new(allocator),
             errors: RefCell::new(vec![]),
         }
@@ -71,6 +98,27 @@ impl<'a> IsolatedDeclarations<'a> {
     fn error(&self, error: OxcDiagnostic) {
         self.errors.borrow_mut().push(error);
     }
+
+    /// Build the lookup table for jsdoc `@internal`.
+    fn build_internal_annotations(source_text: &str, trivias: &Trivias) -> FxHashSet<u32> {
+        let mut set = FxHashSet::default();
+        for comment in trivias.comments() {
+            let has_internal = comment.span.source_text(source_text).contains("@internal");
+            // Use the first jsdoc comment if there are multiple jsdoc comments for the same node.
+            if has_internal && !set.contains(&comment.attached_to) {
+                set.insert(comment.attached_to);
+            }
+        }
+        set
+    }
+
+    /// Check if the node has an `@internal` annotation.
+    fn has_internal_annotation(&self, span: Span) -> bool {
+        if !self.strip_internal {
+            return false;
+        }
+        self.internal_annotations.contains(&span.start)
+    }
 }
 
 impl<'a> IsolatedDeclarations<'a> {
@@ -104,6 +152,9 @@ impl<'a> IsolatedDeclarations<'a> {
         for stmt in Self::remove_function_overloads_implementation(unsafe { self.ast.copy(stmts) })
         {
             if let Some(decl) = stmt.as_declaration() {
+                if self.has_internal_annotation(decl.span()) {
+                    continue;
+                }
                 if let Some(decl) = self.transform_declaration(decl, false) {
                     new_ast_stmts.push(Statement::from(decl));
                 } else {
@@ -138,6 +189,9 @@ impl<'a> IsolatedDeclarations<'a> {
                 match_declaration!(Statement) => {
                     match stmt.to_declaration() {
                         Declaration::VariableDeclaration(decl) => {
+                            if self.has_internal_annotation(decl.span) {
+                                continue;
+                            }
                             variables_declarations.push_back(
                                 // SAFETY: `ast.copy` is unsound! We need to fix.
                                 unsafe { self.ast.copy(&decl.declarations) }
@@ -147,6 +201,9 @@ impl<'a> IsolatedDeclarations<'a> {
                             variable_transformed_indexes.push_back(FxHashSet::default());
                         }
                         Declaration::TSModuleDeclaration(decl) => {
+                            if self.has_internal_annotation(decl.span) {
+                                continue;
+                            }
                             // declare global { ... } or declare module "foo" { ... }
                             // We need to emit it anyway
                             if decl.kind.is_global() || decl.id.is_string_literal() {
@@ -157,11 +214,16 @@ impl<'a> IsolatedDeclarations<'a> {
                         }
                         _ => {}
                     }
-                    new_stmts.push(stmt);
+                    if !self.has_internal_annotation(stmt.span()) {
+                        new_stmts.push(stmt);
+                    }
                 }
                 match_module_declaration!(Statement) => {
                     match stmt.to_module_declaration() {
                         ModuleDeclaration::ExportDefaultDeclaration(decl) => {
+                            if self.has_internal_annotation(decl.span) {
+                                continue;
+                            }
                             transformed_indexes.insert(new_stmts.len());
                             if let Some((var_decl, new_decl)) =
                                 self.transform_export_default_declaration(decl)
@@ -187,6 +249,9 @@ impl<'a> IsolatedDeclarations<'a> {
                         }
 
                         ModuleDeclaration::ExportNamedDeclaration(decl) => {
+                            if self.has_internal_annotation(decl.span) {
+                                continue;
+                            }
                             transformed_indexes.insert(new_stmts.len());
                             if let Some(new_decl) = self.transform_export_named_declaration(decl) {
                                 self.scope.visit_declaration(
@@ -205,6 +270,9 @@ impl<'a> IsolatedDeclarations<'a> {
                             // We must transform this in the end, because we need to know all references
                         }
                         module_declaration => {
+                            if self.has_internal_annotation(module_declaration.span()) {
+                                continue;
+                            }
                             transformed_indexes.insert(new_stmts.len());
                             self.scope.visit_module_declaration(module_declaration);
                         }

crates/oxc_isolated_declarations/src/signatures.rs

@@ -1,5 +1,6 @@
 use oxc_allocator::{CloneIn, Vec};
 use oxc_ast::ast::{TSMethodSignatureKind, TSSignature};
+use oxc_span::GetSpan;
 use rustc_hash::FxHashMap;
 
 use crate::IsolatedDeclarations;
@@ -13,6 +14,9 @@ impl<'a> IsolatedDeclarations<'a> {
         // <name, (requires_inference, first_param_annotation, return_type)>
         let mut method_annotations: FxHashMap<_, (bool, _, _)> = FxHashMap::default();
 
+        // Strip internal signatures
+        signatures.retain(|signature| !self.has_internal_annotation(signature.span()));
+
         signatures.iter_mut().for_each(|signature| {
             if let TSSignature::TSMethodSignature(method) = signature {
                 let Some(name) = method.key.static_name() else {

crates/oxc_isolated_declarations/tests/deno/mod.rs

@@ -5,20 +5,24 @@
 mod tests {
     use oxc_allocator::Allocator;
     use oxc_codegen::CodeGenerator;
-    use oxc_isolated_declarations::IsolatedDeclarations;
+    use oxc_isolated_declarations::{IsolatedDeclarations, IsolatedDeclarationsOptions};
     use oxc_parser::Parser;
     use oxc_span::SourceType;
 
     fn transform_dts_test(source: &str, expected: &str) {
         let allocator = Allocator::default();
         let source_type = SourceType::from_path("test.ts").unwrap();
-        let program = Parser::new(&allocator, source, source_type).parse().program;
-
-        let ret = IsolatedDeclarations::new(&allocator).build(&program);
+        let ret = Parser::new(&allocator, source, source_type).parse();
+        let ret = IsolatedDeclarations::new(
+            &allocator,
+            source,
+            &ret.trivias,
+            IsolatedDeclarationsOptions { strip_internal: true },
+        )
+        .build(&ret.program);
         let actual = CodeGenerator::new().build(&ret.program).source_text;
         let expected_program = Parser::new(&allocator, expected, source_type).parse().program;
         let expected = CodeGenerator::new().build(&expected_program).source_text;
-
         assert_eq!(actual.trim(), expected.trim());
     }
 

crates/oxc_isolated_declarations/tests/fixtures/strip-internal.ts

@@ -0,0 +1,82 @@
+/*
+@internal
+*/
+class StripInternalClass {
+  public test() {
+    console.log("test");
+  }
+}
+
+class StripInternalClassFields {
+  /**
+   * @internal
+   */
+  internalProperty: string = "internal";
+
+  // @internal
+  internalMethod(): void {}
+}
+
+/**
+@internal
+*/
+function stripInternalFunction() {
+  console.log("test");
+}
+
+export { stripInternalFunction, StripInternalClass, StripInternalClassFields };
+
+/**
+@internal
+*/
+export function stripInternalExportedFunction() {
+  console.log("test");
+}
+
+/**
+@internal*/
+export const stripInternalExportedConst = "test";
+
+/**
+@internal*/
+export interface StripInternalExportedInterface {}
+
+export interface StripInternalInterfaceSignatures {
+  /**
+   * @internal
+   */
+  internalMethod(): void;
+  /**
+   * @internal
+   */
+  internalProperty: number;
+  /**@internal */
+  new (): any;
+}
+
+export type StripInternalTypeSignatures = {
+  /**
+   * @internal
+   */
+  internalMethod(): void;
+  /**
+   * @internal
+   */
+  internalProperty: number;
+  /**@internal */
+  new (): any;
+};
+
+export namespace StripInternalNamespaceInner {
+  /**
+   * @internal
+   */
+  export function internalFunction() {
+    console.log("test");
+  }
+}
+
+/**
+ * @internal
+ */
+export namespace StripInternalNamespace {}

crates/oxc_isolated_declarations/tests/mod.rs

@@ -4,7 +4,7 @@ use std::{fs, path::Path, sync::Arc};
 
 use oxc_allocator::Allocator;
 use oxc_codegen::{CodeGenerator, CommentOptions};
-use oxc_isolated_declarations::IsolatedDeclarations;
+use oxc_isolated_declarations::{IsolatedDeclarations, IsolatedDeclarationsOptions};
 use oxc_parser::Parser;
 use oxc_span::SourceType;
 
@@ -13,7 +13,13 @@ fn transform(path: &Path, source_text: &str) -> String {
     let source_type = SourceType::from_path(path).unwrap();
     let parser_ret = Parser::new(&allocator, source_text, source_type).parse();
 
-    let id_ret = IsolatedDeclarations::new(&allocator).build(&parser_ret.program);
+    let id_ret = IsolatedDeclarations::new(
+        &allocator,
+        source_text,
+        &parser_ret.trivias,
+        IsolatedDeclarationsOptions { strip_internal: true },
+    )
+    .build(&parser_ret.program);
     let code = CodeGenerator::new()
         .enable_comment(
             source_text,

crates/oxc_isolated_declarations/tests/snapshots/strip-internal.snap

@@ -0,0 +1,13 @@
+---
+source: crates/oxc_isolated_declarations/tests/mod.rs
+input_file: crates/oxc_isolated_declarations/tests/fixtures/strip-internal.ts
+---
+==================== .D.TS ====================
+
+declare class StripInternalClassFields {}
+export { stripInternalFunction, StripInternalClass, StripInternalClassFields };
+export interface StripInternalInterfaceSignatures {}
+export type StripInternalTypeSignatures = {};
+export declare namespace StripInternalNamespaceInner {
+	export {};
+}