Refactor to share a test utility

3 files changed, 64 insertions, 27 deletions

diff --git a/tests/test_utils/swc.rs b/tests/test_utils/swc.rs
index c0fffa0..80376b8 100644
--- a/tests/test_utils/swc.rs
+++ b/tests/test_utils/swc.rs
@@ -3,8 +3,11 @@ extern crate swc_common;
 extern crate swc_ecma_ast;
 extern crate swc_ecma_parser;
 use micromark::{MdxExpressionKind, MdxSignal};
-use swc_common::{source_map::Pos, BytePos, FileName, SourceFile, Spanned};
+use swc_common::{
+    source_map::Pos, sync::Lrc, BytePos, FileName, FilePathMapping, SourceFile, SourceMap, Spanned,
+};
 use swc_ecma_ast::{EsVersion, Expr, Module};
+use swc_ecma_codegen::{text_writer::JsWriter, Emitter};
 use swc_ecma_parser::{
     error::Error as SwcError, parse_file_as_expr, parse_file_as_module, EsConfig, Syntax,
 };
@@ -164,6 +167,30 @@ pub fn parse_expression_to_tree(
     }
 }
 
+/// Serialize an SWC module.
+/// To do: support comments.
+#[allow(dead_code)]
+pub fn serialize(module: &Module) -> String {
+    let mut buf = vec![];
+    let cm = Lrc::new(SourceMap::new(FilePathMapping::empty()));
+    // let comm = &program.comments as &dyn swc_common::comments::Comments;
+    {
+        let mut emitter = Emitter {
+            cfg: swc_ecma_codegen::Config {
+                ..Default::default()
+            },
+            cm: cm.clone(),
+            // To do: figure out how to pass them.
+            comments: None,
+            wr: JsWriter::new(cm, "\n", &mut buf, None),
+        };
+
+        emitter.emit_module(module).unwrap();
+    }
+
+    String::from_utf8_lossy(&buf).to_string()
+}
+
 /// Check that the resulting AST of ESM is OK.
 ///
 /// This checks that only module declarations (import/exports) are used, not
diff --git a/tests/test_utils/to_document.rs b/tests/test_utils/to_document.rs
index b44d029..96e9d7f 100644
--- a/tests/test_utils/to_document.rs
+++ b/tests/test_utils/to_document.rs
@@ -186,8 +186,10 @@ pub fn to_document(mut program: Program, options: &Options) -> Result<Program, S
                     swc_ecma_ast::DefaultDecl::Fn(func) => swc_ecma_ast::Expr::Fn(func),
                     swc_ecma_ast::DefaultDecl::TsInterfaceDecl(_) => {
                         // To do: improved error? Not sure what a real example of this is?
-                        unreachable!("Cannot use TypeScript interface declarations as default export in MDX")
-                    },
+                        unreachable!(
+                            "Cannot use TypeScript interface declarations as default export in MDX"
+                        )
+                    }
                 }));
             }
             swc_ecma_ast::ModuleItem::ModuleDecl(swc_ecma_ast::ModuleDecl::ExportDefaultExpr(
@@ -206,7 +208,9 @@ pub fn to_document(mut program: Program, options: &Options) -> Result<Program, S
             // export {a, b as c} from 'd'
             // export {a, b as c}
             // ```
-            swc_ecma_ast::ModuleItem::ModuleDecl(swc_ecma_ast::ModuleDecl::ExportNamed(mut named_export)) => {
+            swc_ecma_ast::ModuleItem::ModuleDecl(swc_ecma_ast::ModuleDecl::ExportNamed(
+                mut named_export,
+            )) => {
                 // SWC is currently crashing when generating code, w/o source
                 // map, if an actual location is set on this node.
                 named_export.span = swc_common::DUMMY_SP;
@@ -220,8 +224,11 @@ pub fn to_document(mut program: Program, options: &Options) -> Result<Program, S
                     // branch of this looks interesting, but as far as I
                     // understand it *is not* valid ES.
                     // `export a from 'b'` is a syntax error, even in SWC.
-                    if let swc_ecma_ast::ExportSpecifier::Named(named) = &named_export.specifiers[index] {
-                        if let Some(swc_ecma_ast::ModuleExportName::Ident(ident)) = &named.exported {
+                    if let swc_ecma_ast::ExportSpecifier::Named(named) =
+                        &named_export.specifiers[index]
+                    {
+                        if let Some(swc_ecma_ast::ModuleExportName::Ident(ident)) = &named.exported
+                        {
                             if ident.sym.as_ref() == "default" {
                                 // For some reason the AST supports strings
                                 // instead of identifiers.
@@ -254,29 +261,33 @@ pub fn to_document(mut program: Program, options: &Options) -> Result<Program, S
                     // If there was just a default export, we can drop the original node.
                     if !named_export.specifiers.is_empty() {
                         // Pass through.
-                        replacements.push(swc_ecma_ast::ModuleItem::ModuleDecl(swc_ecma_ast::ModuleDecl::ExportNamed(named_export)));
+                        replacements.push(swc_ecma_ast::ModuleItem::ModuleDecl(
+                            swc_ecma_ast::ModuleDecl::ExportNamed(named_export),
+                        ));
                     }
 
                     // It’s an `export {x} from 'y'`, so generate an import.
                     if let Some(source) = source {
-                        replacements.push(swc_ecma_ast::ModuleItem::ModuleDecl(swc_ecma_ast::ModuleDecl::Import(swc_ecma_ast::ImportDecl {
-                            specifiers: vec![swc_ecma_ast::ImportSpecifier::Named(
-                                swc_ecma_ast::ImportNamedSpecifier {
-                                    local: swc_ecma_ast::Ident {
-                                        sym: "MDXLayout".into(),
-                                        optional: false,
+                        replacements.push(swc_ecma_ast::ModuleItem::ModuleDecl(
+                            swc_ecma_ast::ModuleDecl::Import(swc_ecma_ast::ImportDecl {
+                                specifiers: vec![swc_ecma_ast::ImportSpecifier::Named(
+                                    swc_ecma_ast::ImportNamedSpecifier {
+                                        local: swc_ecma_ast::Ident {
+                                            sym: "MDXLayout".into(),
+                                            optional: false,
+                                            span: swc_common::DUMMY_SP,
+                                        },
+                                        imported: Some(swc_ecma_ast::ModuleExportName::Ident(id)),
                                         span: swc_common::DUMMY_SP,
+                                        is_type_only: false,
                                     },
-                                    imported: Some(swc_ecma_ast::ModuleExportName::Ident( id)),
-                                    span: swc_common::DUMMY_SP,
-                                    is_type_only: false,
-                                },
-                            )],
-                            src: source,
-                            type_only: false,
-                            asserts: None,
-                            span: swc_common::DUMMY_SP,
-                        })))
+                                )],
+                                src: source,
+                                type_only: false,
+                                asserts: None,
+                                span: swc_common::DUMMY_SP,
+                            }),
+                        ))
                     }
                     // It’s an `export {x}`, so generate a variable declaration.
                     else {
@@ -284,13 +295,14 @@ pub fn to_document(mut program: Program, options: &Options) -> Result<Program, S
                     }
                 } else {
                     // Pass through.
-                    replacements.push(swc_ecma_ast::ModuleItem::ModuleDecl(swc_ecma_ast::ModuleDecl::ExportNamed(named_export)));
+                    replacements.push(swc_ecma_ast::ModuleItem::ModuleDecl(
+                        swc_ecma_ast::ModuleDecl::ExportNamed(named_export),
+                    ));
                 }
             }
             swc_ecma_ast::ModuleItem::ModuleDecl(swc_ecma_ast::ModuleDecl::Import(_))
             | swc_ecma_ast::ModuleItem::ModuleDecl(swc_ecma_ast::ModuleDecl::ExportDecl(_))
             | swc_ecma_ast::ModuleItem::ModuleDecl(swc_ecma_ast::ModuleDecl::ExportAll(_))
-            // To do: handle TS things?
             | swc_ecma_ast::ModuleItem::ModuleDecl(swc_ecma_ast::ModuleDecl::TsImportEquals(_))
             | swc_ecma_ast::ModuleItem::ModuleDecl(swc_ecma_ast::ModuleDecl::TsExportAssignment(
                 _,
diff --git a/tests/test_utils/to_swc.rs b/tests/test_utils/to_swc.rs
index 59d60ee..6ed48b6 100644
--- a/tests/test_utils/to_swc.rs
+++ b/tests/test_utils/to_swc.rs
@@ -379,8 +379,6 @@ fn transform_root(
         }
     }
 
-    // To do: remove whitespace?
-    // To do: return a single child if there is one?
     Ok(Some(swc_ecma_ast::JSXElementChild::JSXFragment(
         create_fragment(nodes, node),
     )))