fix: fix resolution when resolving non-relative specifier on tsconfig baseUrl

fixtures/tsconfig/cases/base-url/tsconfig.json

@@ -0,0 +1,5 @@
+{
+  "compilerOptions": {
+    "baseUrl": "./src"
+  }
+}

src/lib.rs

@@ -370,7 +370,9 @@ impl<Fs: FileSystem> ResolverGeneric<Fs> {
         ctx: &mut Ctx,
     ) -> Result<CachedPath, ResolveError> {
         // tsconfig-paths
-        if let Some(path) = self.load_tsconfig_paths(cached_path, specifier, tsconfig, ctx)? {
+        if let Some(path) =
+            self.resolve_tsconfig_compiler_options(cached_path, specifier, tsconfig, ctx)?
+        {
             return Ok(path);
         }
 

src/tests/tsconfig_paths.rs

@@ -2,11 +2,9 @@
 //!
 //! Fixtures copied from <https://github.com/parcel-bundler/parcel/tree/v2/packages/utils/node-resolver-core/test/fixture/tsconfig>.
 
-use std::path::{Path, PathBuf};
-
 use crate::{
-    JSONError, ResolveError, ResolveOptions, Resolver, TsConfig, TsconfigDiscovery,
-    TsconfigOptions, TsconfigReferences,
+    JSONError, ResolveError, ResolveOptions, Resolver, TsconfigDiscovery, TsconfigOptions,
+    TsconfigReferences,
 };
 
 // <https://github.com/parcel-bundler/parcel/blob/b6224fd519f95e68d8b93ba90376fd94c8b76e69/packages/utils/node-resolver-rs/src/lib.rs#L2303>
@@ -28,6 +26,8 @@ pub fn tsconfig_resolve_impl(tsconfig_discovery: bool) {
         (f.join("cases/extends-multiple"), None, "foo", f.join("cases/extends-multiple/foo.js")),
         (f.join("cases/absolute-alias"), None, "/images/foo.js", f.join("cases/absolute-alias/public/images/foo.ts")),
         (f.join("cases/references-extend"), Some("src/index.ts"), "ts-path", f.join("src/foo.js")),
+        // Support `base_url` 3rd case <https://github.com/microsoft/TypeScript/issues/62207>
+        (f.join("cases/base-url"), Some("src/index.ts"), "foo.js", f.join("cases/base-url/src/foo.js")),
     ];
 
     for (dir, subdir, request, expected) in pass {
@@ -63,6 +63,13 @@ pub fn tsconfig_resolve_impl(tsconfig_discovery: bool) {
                 f.join("cases").join("extends-not-found").join("not-found"),
             )),
         ),
+        // no `base_url` <https://github.com/microsoft/TypeScript/issues/62207>
+        (
+            f.clone(),
+            "src/foo.js",
+            f.join("tsconfig.json"),
+            Err(ResolveError::NotFound("src/foo.js".to_string())),
+        ),
     ];
 
     for (path, request, tsconfig, expected) in data {
@@ -173,106 +180,6 @@ fn empty() {
     assert_eq!(resolved_path, Ok(f.join("index.js")));
 }
 
-// <https://github.com/parcel-bundler/parcel/blob/c8f5c97a01f643b4d5c333c02d019ef2618b44a5/packages/utils/node-resolver-rs/src/tsconfig.rs#L193C12-L193C12>
-#[test]
-fn test_paths() {
-    let path = Path::new("/foo");
-    let tsconfig_json = serde_json::json!({
-        "compilerOptions": {
-            "paths": {
-                "jquery": ["node_modules/jquery/dist/jquery"],
-                "*": ["generated/*"],
-                "bar/*": ["test/*"],
-                "bar/baz/*": ["baz/*", "yo/*"],
-                "@/components/*": ["components/*"],
-                "url": ["node_modules/my-url"],
-            }
-        }
-    })
-    .to_string();
-    let tsconfig =
-        TsConfig::parse(true, &path.join("tsconfig.json"), tsconfig_json).unwrap().build();
-
-    let data = [
-        ("jquery", vec!["/foo/node_modules/jquery/dist/jquery"]),
-        ("test", vec!["/foo/generated/test"]),
-        ("test/hello", vec!["/foo/generated/test/hello"]),
-        ("bar/hi", vec!["/foo/test/hi"]),
-        ("bar/baz/hi", vec!["/foo/baz/hi", "/foo/yo/hi"]),
-        ("@/components/button", vec!["/foo/components/button"]),
-        ("url", vec!["/foo/node_modules/my-url"]),
-    ];
-
-    for (specifier, expected) in data {
-        let paths = tsconfig.resolve_path_alias(specifier);
-        let expected = expected
-            .into_iter()
-            .map(PathBuf::from)
-            .chain(std::iter::once(path.join(specifier)))
-            .collect::<Vec<_>>();
-        assert_eq!(paths, expected, "{specifier}");
-    }
-}
-
-// <https://github.com/parcel-bundler/parcel/blob/c8f5c97a01f643b4d5c333c02d019ef2618b44a5/packages/utils/node-resolver-rs/src/tsconfig.rs#L233C6-L233C19>
-#[test]
-fn test_base_url() {
-    let path = Path::new("/foo/tsconfig.json");
-    let tsconfig_json = serde_json::json!({
-        "compilerOptions": {
-            "baseUrl": "./src"
-        }
-    })
-    .to_string();
-    let tsconfig = TsConfig::parse(true, path, tsconfig_json).unwrap().build();
-
-    let data = [
-        ("foo", vec!["/foo/src/foo"]),
-        ("components/button", vec!["/foo/src/components/button"]),
-        ("./jquery", vec![]),
-    ];
-
-    for (specifier, expected) in data {
-        let paths = tsconfig.resolve_path_alias(specifier);
-        let expected = expected.into_iter().map(PathBuf::from).collect::<Vec<_>>();
-        assert_eq!(paths, expected, "{specifier}");
-    }
-}
-
-// <https://github.com/parcel-bundler/parcel/blob/c8f5c97a01f643b4d5c333c02d019ef2618b44a5/packages/utils/node-resolver-rs/src/tsconfig.rs#L252>
-#[test]
-fn test_paths_and_base_url() {
-    let path = Path::new("/foo/tsconfig.json");
-    let tsconfig_json = serde_json::json!({
-        "compilerOptions": {
-            "baseUrl": "./src",
-            "paths": {
-                "*": ["generated/*"],
-                "bar/*": ["test/*"],
-                "bar/baz/*": ["baz/*", "yo/*"],
-                "@/components/*": ["components/*"]
-            }
-        }
-    })
-    .to_string();
-    let tsconfig = TsConfig::parse(true, path, tsconfig_json).unwrap().build();
-
-    let data = [
-        ("test", vec!["/foo/src/generated/test", "/foo/src/test"]),
-        ("test/hello", vec!["/foo/src/generated/test/hello", "/foo/src/test/hello"]),
-        ("bar/hi", vec!["/foo/src/test/hi", "/foo/src/bar/hi"]),
-        ("bar/baz/hi", vec!["/foo/src/baz/hi", "/foo/src/yo/hi", "/foo/src/bar/baz/hi"]),
-        ("@/components/button", vec!["/foo/src/components/button", "/foo/src/@/components/button"]),
-        ("./jquery", vec![]),
-    ];
-
-    for (specifier, expected) in data {
-        let paths = tsconfig.resolve_path_alias(specifier);
-        let expected = expected.into_iter().map(PathBuf::from).collect::<Vec<_>>();
-        assert_eq!(paths, expected, "{specifier}");
-    }
-}
-
 #[test]
 fn test_merge_tsconfig() {
     let resolver = Resolver::default();

src/tsconfig.rs

@@ -390,13 +390,15 @@ impl TsConfig {
         }
 
         let compiler_options = &self.compiler_options;
-        let base_url_iter = vec![compiler_options.paths_base.normalize_with(specifier)];
+
+        // if compiler_options
+        // let base_url_iter = vec![compiler_options.paths_base.normalize_with(specifier)];
 
         let Some(paths_map) = &compiler_options.paths else {
-            return base_url_iter;
+            return vec![];
         };
 
-        let paths = paths_map.get(specifier).map_or_else(
+        paths_map.get(specifier).map_or_else(
             || {
                 let mut longest_prefix_length = 0;
                 let mut longest_suffix_length = 0;
@@ -428,9 +430,14 @@ impl TsConfig {
                 })
             },
             Clone::clone,
-        );
+        )
+    }
 
-        paths.into_iter().chain(base_url_iter).collect()
+    pub(crate) fn resolve_base_url(&self, specifier: &str) -> Option<PathBuf> {
+        self.compiler_options
+            .base_url
+            .is_some()
+            .then(|| self.compiler_options.paths_base.normalize_with(specifier))
     }
 }
 

src/tsconfig_resolver.rs

@@ -255,7 +255,12 @@ impl<Fs: FileSystem> ResolverGeneric<Fs> {
         Ok(())
     }
 
-    pub(crate) fn load_tsconfig_paths(
+    /// Resolves
+    /// * `compilerOptions.paths`
+    /// * `compilerOptions.rootDirs` (if specifier starts with `.`)
+    /// * `compilerOptions.baseUrl` (if specifier does not start with `.`)
+    // <https://github.com/microsoft/TypeScript/blob/v5.9.3/src/compiler/moduleNameResolver.ts#L1550>
+    pub(crate) fn resolve_tsconfig_compiler_options(
         &self,
         cached_path: &CachedPath,
         specifier: &str,
@@ -285,20 +290,25 @@ impl<Fs: FileSystem> ResolverGeneric<Fs> {
         };
         for path in paths {
             let resolved_path = self.cache.value(&path);
-            if let Some(resolution) = self.load_as_file_or_directory(
-                &resolved_path,
-                ".",
-                Some(tsconfig),
-                &mut Ctx::default(),
-            )? {
+            if let Some(resolution) =
+                self.load_as_file_or_directory(&resolved_path, ".", Some(tsconfig), ctx)?
+            {
                 return Ok(Some(resolution));
             }
         }
-        if specifier.starts_with('.')
-            && let Some(path) =
+        if specifier.starts_with('.') {
+            if let Some(path) =
                 self.load_tsconfig_root_dirs(cached_path, specifier, tsconfig, ctx)?
-        {
-            return Ok(Some(path));
+            {
+                return Ok(Some(path));
+            }
+        } else if let Some(path) = tsconfig.resolve_base_url(specifier) {
+            let resolved_path = self.cache.value(&path);
+            if let Some(resolution) =
+                self.load_as_file_or_directory(&resolved_path, ".", Some(tsconfig), ctx)?
+            {
+                return Ok(Some(resolution));
+            }
         }
         Ok(None)
     }