fix: extending tsconfig paths with baseUrl in original tsconfig file (#91)

relates web-infra-dev/rspack#5671

Author: Boshen

fixtures/parcel/tsconfig/extends-paths/src/index.js

@@ -0,0 +1,7 @@
+{
+	"compilerOptions": {
+		"paths": {
+			"@/*": ["./*"]
+		}
+	}
+}

fixtures/parcel/tsconfig/extends-paths/tsconfig.base.json

@@ -0,0 +1,6 @@
+{
+  "extends":	"./tsconfig.base.json",
+  "compilerOptions": {
+    "baseUrl": "src",
+  },
+}

fixtures/parcel/tsconfig/extends-paths/tsconfig.json

@@ -18,24 +18,26 @@ fn tsconfig() {
 
     #[rustfmt::skip]
     let pass = [
-        (f.clone(), "ts-path", f.join("foo.js")),
-        (f.join("nested"), "ts-path", f.join("nested/test.js")),
-        (f.join("tsconfig/index"), "foo", f.join("node_modules/tsconfig-index/foo.js")),
+        (f.clone(), None, "ts-path", f.join("foo.js")),
+        (f.join("nested"), None, "ts-path", f.join("nested/test.js")),
+        (f.join("tsconfig/index"), None, "foo", f.join("node_modules/tsconfig-index/foo.js")),
         // This requires reading package.json.tsconfig field
         // (f.join("tsconfig/field"), "foo", f.join("node_modules/tsconfig-field/foo.js"))
-        (f.join("tsconfig/exports"), "foo", f.join("node_modules/tsconfig-exports/foo.js")),
-        (f.join("tsconfig/extends-extension"), "foo", f.join("tsconfig/extends-extension/foo.js")),
-        (f.join("tsconfig/extends-extensionless"), "foo", f.join("node_modules/tsconfig-field/foo.js"))
+        (f.join("tsconfig/exports"), None, "foo", f.join("node_modules/tsconfig-exports/foo.js")),
+        (f.join("tsconfig/extends-extension"), None, "foo", f.join("tsconfig/extends-extension/foo.js")),
+        (f.join("tsconfig/extends-extensionless"), None, "foo", f.join("node_modules/tsconfig-field/foo.js")),
+        (f.join("tsconfig/extends-paths"), Some("src"), "@/index", f.join("tsconfig/extends-paths/src/index.js")),
     ];
 
-    for (path, request, expected) in pass {
+    for (dir, subdir, request, expected) in pass {
         let resolver = Resolver::new(ResolveOptions {
             tsconfig: Some(TsconfigOptions {
-                config_file: path.join("tsconfig.json"),
+                config_file: dir.join("tsconfig.json"),
                 references: TsconfigReferences::Auto,
             }),
             ..ResolveOptions::default()
         });
+        let path = subdir.map_or(dir.clone(), |subdir| dir.join(subdir));
         let resolved_path = resolver.resolve(&path, request).map(|f| f.full_path());
         assert_eq!(resolved_path, Ok(expected), "{request} {path:?}");
     }

src/tests/tsconfig_paths.rs

@@ -87,13 +87,16 @@ impl TsConfig {
 
     pub fn extend_tsconfig(&mut self, tsconfig: &Self) {
         let compiler_options = &mut self.compiler_options;
-        if compiler_options.base_url.is_none() {
-            compiler_options.base_url = tsconfig.compiler_options.base_url.clone();
-        }
         if compiler_options.paths.is_none() {
-            compiler_options.paths_base = tsconfig.compiler_options.paths_base.clone();
+            compiler_options.paths_base = compiler_options
+                .base_url
+                .as_ref()
+                .map_or_else(|| tsconfig.compiler_options.paths_base.clone(), Clone::clone);
             compiler_options.paths = tsconfig.compiler_options.paths.clone();
         }
+        if compiler_options.base_url.is_none() {
+            compiler_options.base_url = tsconfig.compiler_options.base_url.clone();
+        }
     }
 
     pub fn resolve(&self, path: &Path, specifier: &str) -> Vec<PathBuf> {