fix(op_crates/fetch): correct regexp for fetch header (#8927)

Fix bug in regular expression and make the regular expression more
strict.

In a string passed to new RegExp(), '[\t\s]' is identical to '[ts]' and
not `/[\t\s]/`. For that, the backslash needs to be escaped in the
string. Futhermore, `\t` is the tab character and is included in the
special regexp value `\s` so is unnecessary.

That would reduce the RegExp to new RegExp(`^${value}\\s*;?`) but
there's no point in matching 0 or more space characters followed by 0 or
one semi-colons as that will match no matter what follows `value`.

To make it more strict, require one of space, semicolon, or
end-of-string after value.

1 files changed, 1 insertions, 1 deletions

diff --git a/op_crates/fetch/26_fetch.js b/op_crates/fetch/26_fetch.js
index 0835e12a1..379c88e2f 100644
--- a/op_crates/fetch/26_fetch.js
+++ b/op_crates/fetch/26_fetch.js
@@ -138,7 +138,7 @@
   }
 
   function hasHeaderValueOf(s, value) {
-    return new RegExp(`^${value}[\t\s]*;?`).test(s);
+    return new RegExp(`^${value}(?:[\\s;]|$)`).test(s);
   }
 
   function getHeaderValueParams(value) {