1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
//! Blank page detection utilities.
//!
//! Provides functions to determine if a page is blank based on its text content.
//! A page is considered blank if it contains no meaningful text after normalization.
/// Minimum number of non-whitespace characters to consider a page non-blank.
///
/// Pages with fewer than this many non-whitespace characters are considered blank.
/// This threshold accounts for stray characters, page numbers, or artifacts that
/// may appear on otherwise empty pages.
#[cfg(any(feature = "pdf", feature = "office", feature = "ocr", feature = "ocr-wasm"))]
const MIN_NON_WHITESPACE_CHARS: usize = 3;
/// Determine if a page's text content indicates a blank page.
///
/// A page is blank if it has fewer than [`MIN_NON_WHITESPACE_CHARS`] non-whitespace characters.
///
/// # Arguments
///
/// * `text` - The extracted text content of the page
///
/// # Returns
///
/// `true` if the page is considered blank, `false` otherwise
#[cfg(any(feature = "pdf", feature = "office", feature = "ocr", feature = "ocr-wasm"))]
pub(crate) fn is_page_text_blank(text: &str) -> bool {
let non_whitespace_count = text.chars().filter(|c| !c.is_whitespace()).count();
non_whitespace_count < MIN_NON_WHITESPACE_CHARS
}
#[cfg(all(
test,
any(feature = "pdf", feature = "office", feature = "ocr", feature = "ocr-wasm")
))]
mod tests {
use super::*;
#[test]
fn empty_string_is_blank() {
assert!(is_page_text_blank(""));
}
#[test]
fn whitespace_only_is_blank() {
assert!(is_page_text_blank(" \n\t\n "));
}
#[test]
fn single_character_is_blank() {
assert!(is_page_text_blank("1"));
}
#[test]
fn two_characters_is_blank() {
assert!(is_page_text_blank("- "));
}
#[test]
fn three_non_whitespace_chars_is_not_blank() {
assert!(!is_page_text_blank("abc"));
}
#[test]
fn meaningful_text_is_not_blank() {
assert!(!is_page_text_blank("This page has content."));
}
}