add tsconfig-paths setting to bunfig.toml

src/api/schema.zig

@@ -1617,6 +1617,13 @@ pub const Api = struct {
         }
     };
 
+    /// Configures how the resolver behaves.
+    pub const ResolveOptions = struct {
+        /// Do not consider tsconfig paths. Used primarily for node
+        /// compatibility.
+        ignore_tsconfig: bool = false,
+    };
+
     pub const TransformOptions = struct {
         /// jsx
         jsx: ?Jsx = null,
@@ -1707,6 +1714,7 @@ pub const Api = struct {
         serve_minify_identifiers: ?bool = null,
         bunfig_path: []const u8,
 
+        /// FIXME: unused
         pub fn decode(reader: anytype) anyerror!TransformOptions {
             var this = std.mem.zeroes(TransformOptions);
 

src/bun_js.zig

@@ -232,9 +232,11 @@ pub const Run = struct {
         b.resolver.opts.global_cache = ctx.debug.global_cache;
         b.resolver.opts.prefer_offline_install = (ctx.debug.offline_mode_setting orelse .online) == .offline;
         b.resolver.opts.prefer_latest_install = (ctx.debug.offline_mode_setting orelse .online) == .latest;
+        b.resolver.opts.load_tsconfig_json = ctx.bundler_options.resolve.tsconfig_paths;
         b.options.global_cache = b.resolver.opts.global_cache;
         b.options.prefer_offline_install = b.resolver.opts.prefer_offline_install;
         b.options.prefer_latest_install = b.resolver.opts.prefer_latest_install;
+        b.options.load_tsconfig_json = b.resolver.opts.load_tsconfig_json;
         b.resolver.env_loader = b.env;
 
         b.options.minify_identifiers = ctx.bundler_options.minify_identifiers;

src/bunfig.zig

@@ -218,6 +218,14 @@ pub const Bunfig = struct {
                 this.bunfig.origin = try expr.data.e_string.string(allocator);
             }
 
+            if (json.get("resolve")) |resolve| {
+                try this.expect(resolve, .e_object);
+                if (resolve.get("tsconfig-paths")) |tsconfig_paths| {
+                    try this.expect(tsconfig_paths, .e_boolean);
+                    this.ctx.bundler_options.resolve.tsconfig_paths = tsconfig_paths.asBool().?;
+                }
+            }
+
             if (comptime cmd == .RunCommand or cmd == .AutoCommand) {
                 if (json.get("serve")) |expr| {
                     if (expr.get("port")) |port| {

src/cli.zig

@@ -1549,6 +1549,7 @@ pub const Command = struct {
             banner: []const u8 = "",
             footer: []const u8 = "",
             css_chunking: bool = false,
+            resolve: ResolveOptions = .{},
 
             bake: bool = false,
             bake_debug_dump_server: bool = false,
@@ -1562,6 +1563,9 @@ pub const Command = struct {
             compile_target: Cli.CompileTarget = .{},
             windows_hide_console: bool = false,
             windows_icon: ?[]const u8 = null,
+            pub const ResolveOptions = struct {
+                tsconfig_paths: bool = true,
+            };
         };
 
         pub fn create(allocator: std.mem.Allocator, log: *logger.Log, comptime command: Command.Tag) anyerror!Context {

src/cli/run_command.zig

@@ -819,8 +819,9 @@ pub const RunCommand = struct {
         this_transpiler.resolver.care_about_scripts = true;
         this_transpiler.resolver.store_fd = store_root_fd;
 
-        this_transpiler.resolver.opts.load_tsconfig_json = true;
-        this_transpiler.options.load_tsconfig_json = true;
+        const tsconfig_paths = ctx.bundler_options.resolve.tsconfig_paths;
+        this_transpiler.resolver.opts.load_tsconfig_json = tsconfig_paths;
+        this_transpiler.options.load_tsconfig_json = tsconfig_paths;
 
         this_transpiler.configureLinker();
 

src/resolver/resolver.zig

@@ -1626,7 +1626,28 @@ pub const Resolver = struct {
             }
         }
 
-        // Try to find an "exports" field matching the import path
+        // First, check path overrides from the nearest enclosing TypeScript "tsconfig.json" file
+        if (r.opts.load_tsconfig_json and dir_info.enclosing_tsconfig_json != null) {
+            const tsconfig = dir_info.enclosing_tsconfig_json.?;
+            // Try path substitutions first
+            if (tsconfig.paths.count() > 0) {
+                if (r.matchTSConfigPaths(tsconfig, import_path, kind)) |res| {
+                    return .{ .success = res };
+                }
+            }
+
+            // Try looking up the path relative to the base URL
+            if (tsconfig.hasBaseURL()) {
+                const base = tsconfig.base_url;
+                const paths = [_]string{ base, import_path };
+                const abs = r.fs.absBuf(&paths, bufs(.load_as_file_or_directory_via_tsconfig_base_path));
+
+                if (r.loadAsFileOrDirectory(abs, kind)) |res| {
+                    return .{ .success = res };
+                }
+                // r.allocator.free(abs);
+            }
+        }
 
         var is_self_reference = false;
 

test/js/bun/resolve/resolve.test.ts

@@ -432,6 +432,10 @@ describe("when both package.json imports and tsconfig.json paths are present", (
   let dir: string;
   beforeAll(() => {
     dir = tempDirWithFiles("package-json-imports", {
+      "bunfig.toml": /* toml */ `
+      [resolve]
+      tsconfig-paths = false
+      `,
       "tsconfig.json": /* json */ `
       {
         "compilerOptions": {
@@ -497,17 +501,30 @@ describe("when both package.json imports and tsconfig.json paths are present", (
   });
 
   it("when target is imported from package 'bar', imports from the actual lib directory", () => {
-    const { stdout, stderr, exitCode } = Bun.spawnSync([bunExe(), "src/index.js"], {
-      stdout: "pipe",
-      stderr: "pipe",
-      cwd: join(dir, "packages", "bar"),
-      env: bunEnv,
-    });
-    // const { stdout, exitCode } = Bun.spawnSync([bunExe(), "./packages/bar/src/index.ts"], { cwd: dir, env });
+    const { stdout, stderr, exitCode } = Bun.spawnSync(
+      [bunExe(), "--config=./bunfig.toml", "packages/bar/src/index.js"],
+      {
+        cwd: dir,
+        env,
+        stdout: "pipe",
+        stderr: "pipe",
+      },
+    );
     if (exitCode !== 0) {
       console.error(stderr.toString("utf8"));
     }
     expect(stdout.toString("utf8").trim()).toBe("1");
     expect(exitCode).toBe(0);
   });
+
+  it("when tsconfig-paths is not disabled in bunfig.toml, fails to find 'imported'", () => {
+    const { stderr, exitCode } = Bun.spawnSync([bunExe(), "src/index.js"], {
+      cwd: join(dir, "packages", "bar"),
+      env,
+      stdout: "pipe",
+      stderr: "pipe",
+    });
+    expect(exitCode).not.toBe(0);
+    expect(stderr.toString("utf8")).toContain("Cannot find module './imported'");
+  });
 });