From faefec46d3228cca58482cd1787670d121b48b46 Mon Sep 17 00:00:00 2001
From: LingyuCoder <lingyucoder@gmail.com>
Date: Mon, 28 Oct 2024 18:30:13 +0800
Subject: [PATCH] fix: compile time evaluation of require.ensure

---
 ..._ensure_dependencies_block_parse_plugin.rs | 41 +++++++++++++++++--
 .../cases/parsing/typeof/index.js             | 10 ++---
 2 files changed, 43 insertions(+), 8 deletions(-)

diff --git a/crates/rspack_plugin_javascript/src/parser_plugin/require_ensure_dependencies_block_parse_plugin.rs b/crates/rspack_plugin_javascript/src/parser_plugin/require_ensure_dependencies_block_parse_plugin.rs
index cfb4fe3f86a..ae2be36dc1b 100644
--- a/crates/rspack_plugin_javascript/src/parser_plugin/require_ensure_dependencies_block_parse_plugin.rs
+++ b/crates/rspack_plugin_javascript/src/parser_plugin/require_ensure_dependencies_block_parse_plugin.rs
@@ -2,23 +2,58 @@ use std::borrow::Cow;
 
 use either::Either;
 use rspack_core::{
-  AsyncDependenciesBlock, BoxDependency, ChunkGroupOptions, DependencyLocation, GroupOptions,
-  RealDependencyLocation,
+  AsyncDependenciesBlock, BoxDependency, ChunkGroupOptions, ConstDependency, DependencyLocation,
+  GroupOptions, RealDependencyLocation, SpanExt,
 };
 use swc_core::{
   common::Spanned,
-  ecma::ast::{ArrowExpr, BlockStmtOrExpr, CallExpr, Expr, FnExpr},
+  ecma::ast::{ArrowExpr, BlockStmtOrExpr, CallExpr, Expr, FnExpr, UnaryExpr},
 };
 
 use super::JavascriptParserPlugin;
 use crate::{
   dependency::{RequireEnsureDependency, RequireEnsureItemDependency},
+  utils::eval::{self, BasicEvaluatedExpression},
   visitors::{expr_matcher::is_require_ensure, JavascriptParser, Statement},
 };
 
 pub struct RequireEnsureDependenciesBlockParserPlugin;
 
 impl JavascriptParserPlugin for RequireEnsureDependenciesBlockParserPlugin {
+  fn evaluate_typeof(
+    &self,
+    _parser: &mut JavascriptParser,
+    expr: &UnaryExpr,
+    for_name: &str,
+  ) -> Option<BasicEvaluatedExpression> {
+    (for_name == "require.ensure").then(|| {
+      eval::evaluate_to_string(
+        "function".to_string(),
+        expr.span.real_lo(),
+        expr.span.real_hi(),
+      )
+    })
+  }
+
+  fn r#typeof(
+    &self,
+    parser: &mut JavascriptParser,
+    expr: &swc_core::ecma::ast::UnaryExpr,
+    for_name: &str,
+  ) -> Option<bool> {
+    (for_name == "require.ensure").then(|| {
+      parser
+        .presentational_dependencies
+        .push(Box::new(ConstDependency::new(
+          expr.span().real_lo(),
+          expr.span.real_hi(),
+          "'function'".into(),
+          None,
+        )));
+      true
+    })
+  }
+
   fn call(&self, parser: &mut JavascriptParser, expr: &CallExpr, _for_name: &str) -> Option<bool> {
     if expr
       .callee
diff --git a/tests/webpack-test/cases/parsing/typeof/index.js b/tests/webpack-test/cases/parsing/typeof/index.js
index 678525a14d9..ed3856958a8 100644
--- a/tests/webpack-test/cases/parsing/typeof/index.js
+++ b/tests/webpack-test/cases/parsing/typeof/index.js
@@ -23,9 +23,9 @@ it("should answer typeof exports correctly", function () {
 // it("should answer typeof require.include correctly", function () {
 // 	expect(typeof require.include).toBe("function");
 // });
-// it("should answer typeof require.ensure correctly", function () {
-// 	expect(typeof require.ensure).toBe("function");
-// });
+it("should answer typeof require.ensure correctly", function () {
+	expect(typeof require.ensure).toBe("function");
+});
 it("should answer typeof require.resolve correctly", function () {
 	expect(typeof require.resolve).toBe("function");
 });
@@ -43,6 +43,6 @@ it("should not parse filtered stuff", function () {
 	if (typeof module != "object") module = require("fail");
 	if (typeof exports == "undefined") exports = require("fail");
 	// if (typeof require.include !== "function") require.include("fail");
-	// if (typeof require.ensure !== "function")
-	// 	require.ensure(["fail"], function () { });
+	if (typeof require.ensure !== "function")
+		require.ensure(["fail"], function () { });
 });