fn safe_error_code(input: &str) -> &str {
if !input.is_empty()
&& input
.chars()
.all(|c| c.is_ascii_alphanumeric() || c == '_' || c == '-' || c == '\'')
{
input
} else {
"UNKNOWN"
}
}
fn is_preserved_entity(input: &str) -> bool {
input.starts_with("amp;")
|| input.starts_with("lt;")
|| input.starts_with("gt;")
|| input.starts_with("quot;")
|| input.starts_with("#39;")
|| input
.strip_prefix("#x")
.and_then(|rest| rest.split_once(';'))
.is_some_and(|(hex, _)| !hex.is_empty() && hex.chars().all(|c| c.is_ascii_hexdigit()))
|| input
.strip_prefix('#')
.and_then(|rest| rest.split_once(';'))
.is_some_and(|(digits, _)| {
!digits.is_empty() && digits.chars().all(|c| c.is_ascii_digit())
})
}
fn sanitize_html(input: &str) -> String {
let mut out = String::with_capacity(input.len());
for (idx, ch) in input.char_indices() {
match ch {
'<' => out.push_str("<"),
'>' => out.push_str(">"),
'"' => out.push_str("""),
'\'' => out.push_str("'"),
'&' => {
let rest = input.get(idx + ch.len_utf8()..).unwrap_or_default();
if is_preserved_entity(rest) {
out.push('&');
} else {
out.push_str("&");
}
}
_ => out.push(ch),
}
}
out
}
fn default_error_description(code: &str) -> String {
format!(
"We encountered an unexpected error. Please try again or return to the home page. If you're a developer, you can find <a href='https://better-auth.com/docs/reference/errors/{code}' target='_blank' rel=\"noopener noreferrer\" style='color: var(--foreground); text-decoration: underline;'>more information about the error</a>."
)
}
#[must_use]
pub fn error_page_html(error_code: &str) -> String {
error_page_html_with_description(error_code, None)
}
pub fn error_page_html_with_description(
error_code: &str,
error_description: Option<&str>,
) -> String {
let safe_code = safe_error_code(error_code);
let description =
error_description.map_or_else(|| default_error_description(safe_code), sanitize_html);
let ask_ai_query = format!("What%20does%20the%20error%20code%20{safe_code}%20mean%3F");
format!(
include_str!("page.html"),
safe_code = safe_code,
description = description,
ask_ai_query = ask_ai_query,
)
}
#[must_use]
pub fn error_page_redirect_location(error_code: &str, error_description: Option<&str>) -> String {
let mut query = url::form_urlencoded::Serializer::new(String::new());
_ = query.append_pair("error", safe_error_code(error_code));
if let Some(description) = error_description.filter(|value| !value.is_empty()) {
_ = query.append_pair("error_description", description);
}
format!("/?{}", query.finish())
}