From e4beddb839b4aee6dcaef9f21d87862db3e2d31b Mon Sep 17 00:00:00 2001
From: "taylor.fish" <contact@taylor.fish>
Date: Mon, 11 Aug 2025 13:32:05 -0700
Subject: [PATCH] Reduce false negatives in `ban-words.test.ts` for undefined
 struct fields (#21748)

`ban-words.test.ts` attempts to detect places where a struct field is
given a default value of `undefined`, but it fails to detect cases like
the following:

```zig
foo: *Foo align(1) = undefined,
bar: [16 * 64]Bar = undefined,
baz: Baz(u8, true) = undefined,
```

This PR updates the check to detect more occurrences, while still
avoiding (as far as I can tell) the inclusion of any false positives.

(For internal tracking: fixes STAB-971)

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
---
 test/internal/ban-limits.json   | 2 +-
 test/internal/ban-words.test.ts | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/test/internal/ban-limits.json b/test/internal/ban-limits.json
index 90247d51da..9994ceb9d3 100644
--- a/test/internal/ban-limits.json
+++ b/test/internal/ban-limits.json
@@ -7,7 +7,7 @@
   ".stdDir()": 40,
   ".stdFile()": 18,
   "// autofix": 168,
-  ": [a-zA-Z0-9_\\.\\*\\?\\[\\]\\(\\)]+ = undefined,": 228,
+  ": [^=]+= undefined,$": 261,
   "== alloc.ptr": 0,
   "== allocator.ptr": 0,
   "@import(\"bun\").": 0,
diff --git a/test/internal/ban-words.test.ts b/test/internal/ban-words.test.ts
index 9e8edb43b9..8660778656 100644
--- a/test/internal/ban-words.test.ts
+++ b/test/internal/ban-words.test.ts
@@ -31,7 +31,7 @@ const words: Record<string, { reason: string; regex?: boolean }> = {
   "== alloc.ptr": { reason: "The std.mem.Allocator context pointer can be undefined, which makes this comparison undefined behavior" },
   "!= alloc.ptr": { reason: "The std.mem.Allocator context pointer can be undefined, which makes this comparison undefined behavior" },
 
-  [String.raw`: [a-zA-Z0-9_\.\*\?\[\]\(\)]+ = undefined,`]: { reason: "Do not default a struct field to undefined", regex: true },
+  ": [^=]+= undefined,$": { reason: "Do not default a struct field to undefined", regex: true },
   "usingnamespace": { reason: "Zig 0.15 will remove `usingnamespace`" },
 
   "std.fs.Dir": { reason: "Prefer bun.sys + bun.FD instead of std.fs" },
@@ -69,7 +69,7 @@ for (const source of sources) {
       if (source.startsWith("src" + path.sep + "codegen")) continue;
       const content = await file(source).text();
       for (const word of words_keys) {
-        let regex = words[word].regex ? new RegExp(word, "g") : undefined;
+        let regex = words[word].regex ? new RegExp(word, "gm") : undefined;
         const did_match = regex ? regex.test(content) : content.includes(word);
         if (regex) regex.lastIndex = 0;
         if (did_match) {