fix: template variable not replaced in baseUrl of tsconfig (#61)

Author: stormslowly

fixtures/tsconfig/cases/paths_template_variable/tsconfig3.json

@@ -0,0 +1,3 @@
+{
+  "extends":	"../../tsconfig_template_variable_with_base_url.json"
+}

fixtures/tsconfig/tsconfig_template_variable_with_base_url.json

@@ -0,0 +1,8 @@
+{
+  "compilerOptions": {
+    "baseUrl": "${configDir}",
+    "paths": {
+      "foo": ["${configDir}/foo.js"]
+    }
+  }
+}

src/tests/tsconfig_paths.rs

@@ -237,7 +237,9 @@ async fn test_template_variable() {
     let pass = [
         (f2.clone(), "tsconfig1.json", "foo", f2.join("foo.js")),
         (f2.clone(), "tsconfig2.json", "foo", f2.join("foo.js")),
+        (f2.clone(), "tsconfig3.json", "foo", f2.join("foo.js")),
         (f.clone(), "tsconfig_template_variable.json", "foo", f.join("foo.js")),
+        (f.clone(), "tsconfig_template_variable_with_base_url.json", "foo", f.join("foo.js")),
     ];
 
     for (dir, tsconfig, request, expected) in pass {

src/tsconfig.rs

@@ -1,13 +1,12 @@
+use indexmap::IndexMap;
+use rustc_hash::FxHasher;
+use serde::Deserialize;
 use std::{
     hash::BuildHasherDefault,
     path::{Path, PathBuf},
     sync::Arc,
 };
 
-use indexmap::IndexMap;
-use rustc_hash::FxHasher;
-use serde::Deserialize;
-
 use crate::PathUtil;
 
 pub type CompilerOptionsPathsMap = IndexMap<String, Vec<String>, BuildHasherDefault<FxHasher>>;
@@ -19,6 +18,8 @@ pub enum ExtendsField {
     Multiple(Vec<String>),
 }
 
+const TEMPLATE_VARIABLE: &str = "${configDir}";
+
 #[derive(Debug, Deserialize)]
 #[serde(rename_all = "camelCase")]
 pub struct TsConfig {
@@ -85,8 +86,11 @@ impl TsConfig {
         tsconfig.root = root;
         tsconfig.path = path.to_path_buf();
         let directory = tsconfig.directory().to_path_buf();
-        if let Some(base_url) = tsconfig.compiler_options.base_url {
-            tsconfig.compiler_options.base_url = Some(directory.normalize_with(base_url));
+        if let Some(base_url) = &tsconfig.compiler_options.base_url {
+            // keep the `${configDir}` template variable in the baseUrl
+            if !base_url.starts_with(TEMPLATE_VARIABLE) {
+                tsconfig.compiler_options.base_url = Some(directory.normalize_with(base_url));
+            }
         }
         if tsconfig.compiler_options.paths.is_some() {
             tsconfig.compiler_options.paths_base =
@@ -106,6 +110,16 @@ impl TsConfig {
                     }
                 }
             }
+
+            let mut p = self.compiler_options.paths_base.to_string_lossy().to_string();
+            Self::substitute_template_variable(&dir, &mut p);
+            self.compiler_options.paths_base = p.into();
+
+            if let Some(base_url) = self.compiler_options.base_url.as_mut() {
+                let mut p = base_url.to_string_lossy().to_string();
+                Self::substitute_template_variable(&dir, &mut p);
+                *base_url = p.into();
+            }
         }
         self
     }
@@ -221,9 +235,12 @@ impl TsConfig {
     ///
     /// See <https://github.com/microsoft/TypeScript/pull/58042>
     fn substitute_template_variable(directory: &Path, path: &mut String) {
-        const TEMPLATE_VARIABLE: &str = "${configDir}/";
         if let Some(stripped_path) = path.strip_prefix(TEMPLATE_VARIABLE) {
-            *path = directory.join(stripped_path).to_string_lossy().to_string();
+            if let Some(unleashed_path) = stripped_path.strip_prefix("/") {
+                *path = directory.join(unleashed_path).to_string_lossy().to_string();
+            } else {
+                *path = directory.join(stripped_path).to_string_lossy().to_string();
+            }
         }
     }
 }