Fix panic when parsing declare global with type annotations

src/ast/parseStmt.zig

@@ -1185,6 +1185,17 @@ pub fn ParseStmt(
                 switch (expr.data) {
                     .e_identifier => |ident| {
                         if (p.lexer.token == .t_colon and !opts.hasDecorators()) {
+                            // In TypeScript declare contexts, "identifier: Type" is a type annotation, not a label
+                            if (comptime is_typescript_enabled) {
+                                if (opts.is_typescript_declare) {
+                                    // Skip the colon and type annotation
+                                    try p.lexer.next();
+                                    try p.skipTypeScriptType(.lowest);
+                                    try p.lexer.expectOrInsertSemicolon();
+                                    return p.s(S.TypeScript{}, loc);
+                                }
+                            }
+
                             _ = try p.pushScopeForParsePass(.label, loc);
                             defer p.popScope();
 

test/js/bun/transpiler/declare-global.test.ts

@@ -0,0 +1,71 @@
+import { expect, test } from "bun:test";
+import { bunEnv, bunExe, tempDir } from "harness";
+
+test("declare global with type annotation should not crash", async () => {
+  using dir = tempDir("declare-global-test", {
+    "test.ts": `
+declare global {
+  A: 'a';
+}
+
+() => {};
+
+console.log("SUCCESS");
+`,
+  });
+
+  await using proc = Bun.spawn({
+    cmd: [bunExe(), "test.ts"],
+    env: bunEnv,
+    cwd: String(dir),
+    stdout: "pipe",
+    stderr: "pipe",
+  });
+
+  const [stdout, stderr, exitCode] = await Promise.all([proc.stdout.text(), proc.stderr.text(), proc.exited]);
+
+  expect(stderr).not.toContain("panic");
+  expect(stderr).not.toContain("Scope mismatch");
+  expect(stdout).toContain("SUCCESS");
+  expect(exitCode).toBe(0);
+});
+
+test("declare global with multiple type annotations and nested arrow functions", async () => {
+  using dir = tempDir("declare-global-multi", {
+    "test.ts": `
+declare global {
+  TIMER: NodeJS.Timeout;
+  FOO: string;
+  BAR: number;
+  BAZ: () => void;
+}
+
+// Test nested arrow functions to ensure scope handling is correct
+const fn = () => {
+  const nested = () => {
+    const deeplyNested = () => "nested";
+    return deeplyNested();
+  };
+  return nested();
+};
+
+console.log(fn());
+console.log("SUCCESS");
+`,
+  });
+
+  await using proc = Bun.spawn({
+    cmd: [bunExe(), "test.ts"],
+    env: bunEnv,
+    cwd: String(dir),
+    stdout: "pipe",
+    stderr: "pipe",
+  });
+
+  const [stdout, stderr, exitCode] = await Promise.all([proc.stdout.text(), proc.stderr.text(), proc.exited]);
+
+  expect(stderr).not.toContain("panic");
+  expect(stderr).not.toContain("Scope mismatch");
+  expect(stdout).toContain("SUCCESS");
+  expect(exitCode).toBe(0);
+});