fix: handle missing asset hash gracefully instead of panicking

The bundler was panicking with "cached asset not found" when there was an inconsistency between IncrementalGraph.bundled_files and Assets.path_map. This could happen due to race conditions or state inconsistencies. The fix gracefully handles the case where an asset is cached in bundled_files but missing from assets.path_map by falling back to normal asset processing instead of panicking. 🤖 Generated with [Claude Code](https://claude.ai/code) Co-Authored-By: Claude <noreply@anthropic.com>
2026-02-09 10:28:47 +00:00 · 2025-08-17 14:48:59 +00:00
2 changed files with 98 additions and 8 deletions
--- a/src/bundler/bundle_v2.zig
+++ b/src/bundler/bundle_v2.zig
@@ -3034,14 +3034,23 @@ pub const BundleV2 = struct {
                    if (loader == .html and entry.kind == .asset) {
                        // Overload `path.text` to point to the final URL
                        // This information cannot be queried while printing because a lock wouldn't get held.
-                        const hash = dev_server.assets.getHash(path.text) orelse @panic("cached asset not found");
-                        import_record.path.text = path.text;
-                        import_record.path.namespace = "file";
-                        import_record.path.pretty = std.fmt.allocPrint(this.graph.allocator, bun.bake.DevServer.asset_prefix ++ "/{s}{s}", .{
-                            &std.fmt.bytesToHex(std.mem.asBytes(&hash), .lower),
-                            std.fs.path.extension(path.text),
-                        }) catch bun.outOfMemory();
-                        import_record.path.is_disabled = false;
+                        if (dev_server.assets.getHash(path.text)) |hash| {
+                            import_record.path.text = path.text;
+                            import_record.path.namespace = "file";
+                            import_record.path.pretty = std.fmt.allocPrint(this.graph.allocator, bun.bake.DevServer.asset_prefix ++ "/{s}{s}", .{
+                                &std.fmt.bytesToHex(std.mem.asBytes(&hash), .lower),
+                                std.fs.path.extension(path.text),
+                            }) catch bun.outOfMemory();
+                            import_record.path.is_disabled = false;
+                        } else {
+                            // Asset is cached in bundled_files but not in assets.path_map
+                            // This can happen due to race conditions or inconsistent state
+                            // Fall back to normal asset processing
+                            import_record.path.text = path.text;
+                            import_record.path.pretty = rel;
+                            import_record.path = this.pathWithPrettyInitialized(path.*, target) catch bun.outOfMemory();
+                            import_record.path.is_disabled = false;
+                        }
                    } else {
                        import_record.path.text = path.text;
                        import_record.path.pretty = rel;
--- a/test/regression/issue/asset-cache-race-condition.test.ts
+++ b/test/regression/issue/asset-cache-race-condition.test.ts
@@ -0,0 +1,81 @@
+import { test, expect } from "bun:test";
+import { tempDirWithFiles, bunEnv } from "harness";
+import path from "path";
+
+test("asset cache race condition should not panic", async () => {
+  // This test ensures that when there's an inconsistency between bundled_files and assets.path_map,
+  // the bundler gracefully handles the missing asset hash instead of panicking
+  
+  const dir = tempDirWithFiles("asset-cache-race", {
+    "index.html": `
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Test</title>
+</head>
+<body>
+    <img src="./test.png" alt="test">
+    <div style="background: url('./test.png')"></div>
+</body>
+</html>
+    `,
+    "test.png": Buffer.from(
+      "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8/5+hHgAHggJ/PchI7wAAAABJRU5ErkJggg==",
+      "base64"
+    ),
+    "app.ts": `
+import './test.png';
+console.log("Hello from app.ts");
+    `,
+  });
+
+  // Test HTML bundling with assets
+  const proc1 = Bun.spawn({
+    cmd: [
+      process.execPath,
+      "build", 
+      "index.html",
+      "--outdir=dist",
+    ],
+    env: bunEnv,
+    cwd: dir,
+    stderr: "pipe",
+    stdout: "pipe",
+  });
+
+  const [stdout1, stderr1, exitCode1] = await Promise.all([
+    proc1.stdout.text(),
+    proc1.stderr.text(),
+    proc1.exited,
+  ]);
+
+  // Should not panic or crash
+  expect(exitCode1).toBe(0);
+  expect(stderr1).not.toContain("panic");
+  expect(stderr1).not.toContain("cached asset not found");
+
+  // Test TS bundling with assets
+  const proc2 = Bun.spawn({
+    cmd: [
+      process.execPath,
+      "build", 
+      "app.ts",
+      "--outdir=dist2",
+    ],
+    env: bunEnv,
+    cwd: dir,
+    stderr: "pipe",
+    stdout: "pipe",
+  });
+
+  const [stdout2, stderr2, exitCode2] = await Promise.all([
+    proc2.stdout.text(),
+    proc2.stderr.text(),
+    proc2.exited,
+  ]);
+
+  // Should not panic or crash
+  expect(exitCode2).toBe(0);
+  expect(stderr2).not.toContain("panic");
+  expect(stderr2).not.toContain("cached asset not found");
+});