Add import.meta.main (#1835)

11 files changed, 63 insertions, 26 deletions

diff --git a/js/lib.web_assembly.d.ts b/js/lib.web_assembly.d.ts
index 1ec6a7943..e69c4c629 100644
--- a/js/lib.web_assembly.d.ts
+++ b/js/lib.web_assembly.d.ts
@@ -165,4 +165,5 @@ declare namespace WebAssembly {
 // TODO Move ImportMeta intos its own lib.import_meta.d.ts file?
 interface ImportMeta {
   url: string;
+  main: boolean;
 }
diff --git a/libdeno/binding.cc b/libdeno/binding.cc
index f7ee977e8..f640fe83c 100644
--- a/libdeno/binding.cc
+++ b/libdeno/binding.cc
@@ -265,7 +265,8 @@ v8::ScriptOrigin ModuleOrigin(v8::Isolate* isolate,
                           v8::True(isolate));
 }
 
-deno_mod DenoIsolate::RegisterModule(const char* name, const char* source) {
+deno_mod DenoIsolate::RegisterModule(bool main, const char* name,
+                                     const char* source) {
   v8::Isolate::Scope isolate_scope(isolate_);
   v8::Locker locker(isolate_);
   v8::HandleScope handle_scope(isolate_);
@@ -300,8 +301,9 @@ deno_mod DenoIsolate::RegisterModule(const char* name, const char* source) {
     import_specifiers.push_back(*specifier_utf8);
   }
 
-  mods_.emplace(std::piecewise_construct, std::make_tuple(id),
-                std::make_tuple(isolate_, module, name, import_specifiers));
+  mods_.emplace(
+      std::piecewise_construct, std::make_tuple(id),
+      std::make_tuple(isolate_, module, main, name, import_specifiers));
   mods_by_name_[name] = id;
 
   return id;
@@ -519,8 +521,10 @@ void HostInitializeImportMetaObjectCallback(v8::Local<v8::Context> context,
   auto* info = d->GetModuleInfo(id);
 
   const char* url = info->name.c_str();
+  const bool main = info->main;
 
   meta->CreateDataProperty(context, v8_str("url"), v8_str(url)).ToChecked();
+  meta->CreateDataProperty(context, v8_str("main"), v8_bool(main)).ToChecked();
 }
 
 void DenoIsolate::AddIsolate(v8::Isolate* isolate) {
diff --git a/libdeno/deno.h b/libdeno/deno.h
index e48dd8cbe..6be0b5625 100644
--- a/libdeno/deno.h
+++ b/libdeno/deno.h
@@ -83,7 +83,7 @@ void deno_terminate_execution(Deno* d);
 typedef int deno_mod;
 
 // Returns zero on error - check deno_last_exception().
-deno_mod deno_mod_new(Deno* d, const char* name, const char* source);
+deno_mod deno_mod_new(Deno* d, bool main, const char* name, const char* source);
 
 size_t deno_mod_imports_len(Deno* d, deno_mod id);
 
diff --git a/libdeno/internal.h b/libdeno/internal.h
index a87ec0fdc..720966407 100644
--- a/libdeno/internal.h
+++ b/libdeno/internal.h
@@ -13,13 +13,14 @@
 namespace deno {
 
 struct ModuleInfo {
+  bool main;
   std::string name;
   v8::Persistent<v8::Module> handle;
   std::vector<std::string> import_specifiers;
 
-  ModuleInfo(v8::Isolate* isolate, v8::Local<v8::Module> module,
+  ModuleInfo(v8::Isolate* isolate, v8::Local<v8::Module> module, bool main_,
              const char* name_, std::vector<std::string> import_specifiers_)
-      : name(name_), import_specifiers(import_specifiers_) {
+      : main(main_), name(name_), import_specifiers(import_specifiers_) {
     handle.Reset(isolate, module);
   }
 };
@@ -61,7 +62,7 @@ class DenoIsolate {
 
   void AddIsolate(v8::Isolate* isolate);
 
-  deno_mod RegisterModule(const char* name, const char* source);
+  deno_mod RegisterModule(bool main, const char* name, const char* source);
   v8::Local<v8::Object> GetBuiltinModules();
   void ClearModules();
 
diff --git a/libdeno/modules.cc b/libdeno/modules.cc
index ca2928e04..d8b2f48d1 100644
--- a/libdeno/modules.cc
+++ b/libdeno/modules.cc
@@ -88,7 +88,7 @@ v8::MaybeLocal<v8::Module> ResolveCallback(Local<Context> context,
             id = it->second;
           } else {
             std::string src = BuiltinModuleSrc(context, specifier);
-            id = d->RegisterModule(req_str.c_str(), src.c_str());
+            id = d->RegisterModule(false, req_str.c_str(), src.c_str());
           }
         } else {
           id = d->resolve_cb_(d->user_data_, req_str.c_str(), referrer_id);
@@ -116,10 +116,10 @@ v8::MaybeLocal<v8::Module> ResolveCallback(Local<Context> context,
 
 extern "C" {
 
-deno_mod deno_mod_new(Deno* d_, const char* name_cstr,
+deno_mod deno_mod_new(Deno* d_, bool main, const char* name_cstr,
                       const char* source_cstr) {
   auto* d = unwrap(d_);
-  return d->RegisterModule(name_cstr, source_cstr);
+  return d->RegisterModule(main, name_cstr, source_cstr);
 }
 
 const char* deno_mod_name(Deno* d_, deno_mod id) {
diff --git a/libdeno/modules_test.cc b/libdeno/modules_test.cc
index f637ae070..d41c38b8e 100644
--- a/libdeno/modules_test.cc
+++ b/libdeno/modules_test.cc
@@ -14,7 +14,7 @@ TEST(ModulesTest, Resolution) {
   Deno* d = deno_new(deno_config{0, empty, empty, recv_cb});
   EXPECT_EQ(0, exec_count);
 
-  static deno_mod a = deno_mod_new(d, "a.js",
+  static deno_mod a = deno_mod_new(d, true, "a.js",
                                    "import { b } from 'b.js'\n"
                                    "if (b() != 'b') throw Error();\n"
                                    "libdeno.send(new Uint8Array([4]));");
@@ -22,7 +22,7 @@ TEST(ModulesTest, Resolution) {
   EXPECT_EQ(nullptr, deno_last_exception(d));
 
   const char* b_src = "export function b() { return 'b' }";
-  static deno_mod b = deno_mod_new(d, "b.js", b_src);
+  static deno_mod b = deno_mod_new(d, false, "b.js", b_src);
   EXPECT_NE(b, 0);
   EXPECT_EQ(nullptr, deno_last_exception(d));
 
@@ -72,7 +72,7 @@ TEST(ModulesTest, BuiltinModules) {
   EXPECT_EQ(nullptr, deno_last_exception(d));
 
   static deno_mod a =
-      deno_mod_new(d, "a.js",
+      deno_mod_new(d, true, "a.js",
                    "import { b } from 'b.js'\n"
                    "import * as deno from 'deno'\n"
                    "if (b() != 'b') throw Error('b');\n"
@@ -82,7 +82,7 @@ TEST(ModulesTest, BuiltinModules) {
   EXPECT_EQ(nullptr, deno_last_exception(d));
 
   const char* b_src = "export function b() { return 'b' }";
-  static deno_mod b = deno_mod_new(d, "b.js", b_src);
+  static deno_mod b = deno_mod_new(d, false, "b.js", b_src);
   EXPECT_NE(b, 0);
   EXPECT_EQ(nullptr, deno_last_exception(d));
 
@@ -134,7 +134,7 @@ TEST(ModulesTest, BuiltinModules2) {
   EXPECT_EQ(nullptr, deno_last_exception(d));
 
   static deno_mod a =
-      deno_mod_new(d, "a.js",
+      deno_mod_new(d, true, "a.js",
                    "import * as b1 from 'builtin1'\n"
                    "import * as b2 from 'builtin2'\n"
                    "if (b1.foo != 'bar') throw Error('bad1');\n"
@@ -168,7 +168,7 @@ TEST(ModulesTest, BuiltinModules3) {
   EXPECT_EQ(nullptr, deno_last_exception(d));
 
   static deno_mod a =
-      deno_mod_new(d, "a.js",
+      deno_mod_new(d, true, "a.js",
                    "import * as b1 from 'builtin'\n"
                    "import * as b2 from 'b.js'\n"
                    "if (b1.foo != 'bar') throw Error('bad1');\n"
@@ -181,7 +181,7 @@ TEST(ModulesTest, BuiltinModules3) {
   EXPECT_STREQ("builtin", deno_mod_imports_get(d, a, 0));
   EXPECT_STREQ("b.js", deno_mod_imports_get(d, a, 1));
 
-  static deno_mod b = deno_mod_new(d, "b.js",
+  static deno_mod b = deno_mod_new(d, false, "b.js",
                                    "import { foo } from 'builtin';\n"
                                    "export function bar() { return foo }\n");
   EXPECT_NE(b, 0);
@@ -218,7 +218,7 @@ TEST(ModulesTest, ResolutionError) {
   Deno* d = deno_new(deno_config{0, empty, empty, recv_cb});
   EXPECT_EQ(0, exec_count);
 
-  static deno_mod a = deno_mod_new(d, "a.js",
+  static deno_mod a = deno_mod_new(d, true, "a.js",
                                    "import 'bad'\n"
                                    "libdeno.send(new Uint8Array([4]));");
   EXPECT_NE(a, 0);
@@ -252,7 +252,7 @@ TEST(ModulesTest, ImportMetaUrl) {
   EXPECT_EQ(0, exec_count);
 
   static deno_mod a =
-      deno_mod_new(d, "a.js",
+      deno_mod_new(d, true, "a.js",
                    "if ('a.js' != import.meta.url) throw 'hmm'\n"
                    "libdeno.send(new Uint8Array([4]));");
   EXPECT_NE(a, 0);
@@ -266,3 +266,32 @@ TEST(ModulesTest, ImportMetaUrl) {
   EXPECT_EQ(nullptr, deno_last_exception(d));
   EXPECT_EQ(1, exec_count);
 }
+
+TEST(ModulesTest, ImportMetaMain) {
+  Deno* d = deno_new(deno_config{0, empty, empty, recv_cb});
+
+  const char* throw_not_main_src = "if (!import.meta.main) throw 'err'";
+  static deno_mod throw_not_main =
+      deno_mod_new(d, true, "a.js", throw_not_main_src);
+  EXPECT_NE(throw_not_main, 0);
+  EXPECT_EQ(nullptr, deno_last_exception(d));
+
+  deno_mod_instantiate(d, d, throw_not_main, nullptr);
+  EXPECT_EQ(nullptr, deno_last_exception(d));
+
+  deno_mod_evaluate(d, d, throw_not_main);
+  EXPECT_EQ(nullptr, deno_last_exception(d));
+
+  const char* throw_main_src = "if (import.meta.main) throw 'err'";
+  static deno_mod throw_main = deno_mod_new(d, false, "b.js", throw_main_src);
+  EXPECT_NE(throw_main, 0);
+  EXPECT_EQ(nullptr, deno_last_exception(d));
+
+  deno_mod_instantiate(d, d, throw_main, nullptr);
+  EXPECT_EQ(nullptr, deno_last_exception(d));
+
+  deno_mod_evaluate(d, d, throw_main);
+  EXPECT_EQ(nullptr, deno_last_exception(d));
+
+  deno_delete(d);
+}
diff --git a/src/isolate.rs b/src/isolate.rs
index 63f45b5df..b723738d7 100644
--- a/src/isolate.rs
+++ b/src/isolate.rs
@@ -283,6 +283,7 @@ impl Isolate {
 
   pub fn mod_new(
     &mut self,
+    main: bool,
     name: String,
     source: String,
   ) -> Result<libdeno::deno_mod, JSError> {
@@ -293,7 +294,7 @@ impl Isolate {
     let source_ptr = source_.as_ptr() as *const c_char;
 
     let id = unsafe {
-      libdeno::deno_mod_new(self.libdeno_isolate, name_ptr, source_ptr)
+      libdeno::deno_mod_new(self.libdeno_isolate, main, name_ptr, source_ptr)
     };
     if let Some(js_error) = self.last_exception() {
       assert_eq!(id, 0);
@@ -345,7 +346,7 @@ impl Isolate {
           &referrer_name,
         )?;
         let child_id =
-          self.mod_new(out.module_name.clone(), out.js_source())?;
+          self.mod_new(false, out.module_name.clone(), out.js_source())?;
 
         self.mod_load_deps(child_id)?;
       }
@@ -391,7 +392,7 @@ impl Isolate {
         .map_err(RustOrJsError::from)?;
 
     let id = self
-      .mod_new(out.module_name.clone(), out.js_source())
+      .mod_new(true, out.module_name.clone(), out.js_source())
       .map_err(RustOrJsError::from)?;
 
     self.mod_load_deps(id)?;
diff --git a/src/libdeno.rs b/src/libdeno.rs
index a3a711b65..204f817b5 100644
--- a/src/libdeno.rs
+++ b/src/libdeno.rs
@@ -154,6 +154,7 @@ extern "C" {
 
   pub fn deno_mod_new(
     i: *const isolate,
+    main: bool,
     name: *const c_char,
     source: *const c_char,
   ) -> deno_mod;
diff --git a/tests/import_meta.ts b/tests/import_meta.ts
index 8f2712068..2f3bec9ed 100644
--- a/tests/import_meta.ts
+++ b/tests/import_meta.ts
@@ -1,3 +1,3 @@
-console.log("import_meta", import.meta.url);
+console.log("import_meta", import.meta.url, import.meta.main);
 
 import "import_meta2.ts";
diff --git a/tests/import_meta.ts.out b/tests/import_meta.ts.out
index c43cea6fd..f38aa98ea 100644
--- a/tests/import_meta.ts.out
+++ b/tests/import_meta.ts.out
@@ -1,2 +1,2 @@
-import_meta2 [WILDCARD]import_meta2.ts
-import_meta [WILDCARD]import_meta.ts
+import_meta2 [WILDCARD]import_meta2.ts false
+import_meta [WILDCARD]import_meta.ts true
diff --git a/tests/import_meta2.ts b/tests/import_meta2.ts
index b64265b5b..7f59a5a46 100644
--- a/tests/import_meta2.ts
+++ b/tests/import_meta2.ts
@@ -1 +1 @@
-console.log("import_meta2", import.meta.url);
+console.log("import_meta2", import.meta.url, import.meta.main);