From 93fdbed85dc3fc4a714a746b4fc29ed5845ffccb Mon Sep 17 00:00:00 2001
From: pfg <pfg@pfg.pw>
Date: Fri, 6 Dec 2024 20:03:20 -0800
Subject: [PATCH] add back whitespace checks but limited to 33 bytes

---
 src/bake/DevServer.zig    |  2 +-
 src/bundler.zig           |  8 ++++++++
 src/bundler/bundle_v2.zig | 12 ++++++++++++
 src/string_immutable.zig  |  4 ++++
 4 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/src/bake/DevServer.zig b/src/bake/DevServer.zig
index 9004984894..35394a1293 100644
--- a/src/bake/DevServer.zig
+++ b/src/bake/DevServer.zig
@@ -2051,7 +2051,7 @@ pub fn IncrementalGraph(side: bake.Side) type {
             if (Environment.allow_assert) {
                 switch (kind) {
                     .css => bun.assert(code.len == 0),
-                    .js => if (code.len == 0 or (code.len < 33 and std.mem.trimLeft(u8, code, "\n\r ").len == 0)) {
+                    .js => if (bun.strings.isSmallAndOnlyWhitespace(code)) {
                         // Should at least contain the function wrapper
                         bun.Output.panic("Empty chunk is impossible: {s} {s}", .{
                             key,
diff --git a/src/bundler.zig b/src/bundler.zig
index 54274b5ed1..f64cebed1f 100644
--- a/src/bundler.zig
+++ b/src/bundler.zig
@@ -1137,6 +1137,10 @@ pub const Bundler = struct {
             .ts,
             .tsx,
             => {
+                if (bun.strings.isSmallAndOnlyWhitespace(source.contents)) {
+                    return ParseResult{ .source = source, .input_fd = input_fd, .loader = loader, .empty = true, .ast = js_ast.Ast.empty };
+                }
+
                 // wasm magic number
                 if (source.isWebAssembly()) {
                     return ParseResult{
@@ -1251,6 +1255,10 @@ pub const Bundler = struct {
             },
             // TODO: use lazy export AST
             inline .toml, .json => |kind| {
+                if (bun.strings.isSmallAndOnlyWhitespace(source.contents)) {
+                    return ParseResult{ .source = source, .input_fd = input_fd, .loader = loader, .empty = true, .ast = js_ast.Ast.empty };
+                }
+
                 var expr = if (kind == .json)
                     // We allow importing tsconfig.*.json or jsconfig.*.json with comments
                     // These files implicitly become JSONC files, which aligns with the behavior of text editors.
diff --git a/src/bundler/bundle_v2.zig b/src/bundler/bundle_v2.zig
index bbe7ee1543..55e3e220c1 100644
--- a/src/bundler/bundle_v2.zig
+++ b/src/bundler/bundle_v2.zig
@@ -3587,6 +3587,10 @@ pub const ParseTask = struct {
     ) !JSAst {
         switch (loader) {
             .jsx, .tsx, .js, .ts => {
+                if (bun.strings.isSmallAndOnlyWhitespace(source.contents)) return switch (opts.module_type == .esm) {
+                    inline else => |as_undefined| try getEmptyAST(log, bundler, opts, allocator, source, if (as_undefined) E.Undefined else E.Object),
+                };
+
                 const trace = tracer(@src(), "ParseJS");
                 defer trace.end();
                 return if (try resolver.caches.js.parse(
@@ -3609,12 +3613,20 @@ pub const ParseTask = struct {
                 };
             },
             .json => {
+                if (strings.isSmallAndOnlyWhitespace(source.contents)) return switch (opts.module_type == .esm) {
+                    inline else => |as_undefined| try getEmptyAST(log, bundler, opts, allocator, source, if (as_undefined) E.Undefined else E.Object),
+                };
+
                 const trace = tracer(@src(), "ParseJSON");
                 defer trace.end();
                 const root = (try resolver.caches.json.parsePackageJSON(log, source, allocator, false)) orelse Expr.init(E.Object, E.Object{}, Logger.Loc.Empty);
                 return JSAst.init((try js_parser.newLazyExportAST(allocator, bundler.options.define, opts, log, root, &source, "")).?);
             },
             .toml => {
+                if (strings.isSmallAndOnlyWhitespace(source.contents)) return switch (opts.module_type == .esm) {
+                    inline else => |as_undefined| try getEmptyAST(log, bundler, opts, allocator, source, if (as_undefined) E.Undefined else E.Object),
+                };
+
                 const trace = tracer(@src(), "ParseTOML");
                 defer trace.end();
                 const root = try TOML.parse(&source, log, allocator, false);
diff --git a/src/string_immutable.zig b/src/string_immutable.zig
index bfac2b814f..af9cadf0a1 100644
--- a/src/string_immutable.zig
+++ b/src/string_immutable.zig
@@ -4930,6 +4930,10 @@ pub fn trim(slice: anytype, comptime values_to_strip: []const u8) @TypeOf(slice)
     return slice[begin..end];
 }
 
+pub fn isSmallAndOnlyWhitespace(slice: string) bool {
+    return slice.len == 0 or (slice.len < 33 and std.mem.trimLeft(u8, slice, "\n\r ").len == 0);
+}
+
 pub const whitespace_chars = [_]u8{ ' ', '\t', '\n', '\r', std.ascii.control_code.vt, std.ascii.control_code.ff };
 
 pub fn lengthOfLeadingWhitespaceASCII(slice: string) usize {