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Merged
enijburg merged 2 commits into from
May 15, 2026
Merged

Extract prompt UI and tests into separate modules (vertical-slice refactor) #15

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d050fe4
Refactor main into UI prompt and dedicated tests module
enijburg May 15, 2026
2da61c1
Fix prompt module style import for PrintStyledContent
enijburg May 15, 2026
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301 changes: 3 additions & 298 deletions src/main.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -17,6 +17,7 @@ use crossterm::{
terminal::{self, ClearType},
};
use memmap2::Mmap;
use ui::prompt::{prompt_find, prompt_goto_line};

#[derive(Parser, Debug)]
#[command(version, about = "Memory-mapped large file viewer for Windows x64")]
Expand Down Expand Up @@ -1421,303 +1422,7 @@ fn run_event_loop(viewer: &mut Viewer, out: &mut impl Write) -> Result<()> {
Ok(())
}

fn prompt_goto_line(viewer: &Viewer, out: &mut impl Write) -> Result<Option<usize>> {
let mut input = String::new();

loop {
let (width, height) = terminal::size().context("Failed to get terminal size")?;
let prompt = format!(
"Goto line (1-{}, Enter=go, Esc=cancel): {}",
viewer.line_count(),
input
);
let clipped_prompt = clip_to_width(&prompt, width as usize);
let y = height.saturating_sub(1);

queue!(
out,
cursor::MoveTo(0, y),
terminal::Clear(ClearType::CurrentLine),
style::PrintStyledContent(clipped_prompt.reverse())
)?;
out.flush().context("Failed to flush terminal output")?;

match event::read().context("Failed reading terminal event")? {
Event::Key(key) if key.kind == KeyEventKind::Press => match key.code {
KeyCode::Esc => return Ok(None),
KeyCode::Enter => {
if input.is_empty() {
return Ok(None);
}

if let Ok(line_number) = input.parse::<usize>() {
if line_number >= 1 {
return Ok(Some(line_number));
}
}
}
KeyCode::Backspace => {
input.pop();
}
KeyCode::Char(c) if c.is_ascii_digit() => {
input.push(c);
}
_ => {}
},
_ => {}
}
}
}

fn prompt_find(viewer: &Viewer, out: &mut impl Write) -> Result<Option<String>> {
let mut input = viewer
.search_query
.as_ref()
.map(|query| String::from_utf8_lossy(query).to_string())
.unwrap_or_default();

loop {
let (width, height) = terminal::size().context("Failed to get terminal size")?;
let prompt = format!("Find text (Enter=find, Esc=cancel): {}", input);
let clipped_prompt = clip_to_width(&prompt, width as usize);
let y = height.saturating_sub(1);

queue!(
out,
cursor::MoveTo(0, y),
terminal::Clear(ClearType::CurrentLine),
style::PrintStyledContent(clipped_prompt.reverse())
)?;
out.flush().context("Failed to flush terminal output")?;

match event::read().context("Failed reading terminal event")? {
Event::Key(key) if key.kind == KeyEventKind::Press => match key.code {
KeyCode::Esc => return Ok(None),
KeyCode::Enter => {
if input.is_empty() {
return Ok(None);
}
return Ok(Some(input));
}
KeyCode::Backspace => {
input.pop();
}
KeyCode::Char(c) => {
if !c.is_control() {
input.push(c);
}
}
_ => {}
},
_ => {}
}
}
}
mod ui;

#[cfg(test)]
mod tests {
use super::{
centered_top_line, classify_json_line, classify_xml_line, detect_csv_separator,
format_json_for_display, format_xml_for_display, parse_csv_separator, skipped_prefix_len,
JsonTokenClass, Viewer, XmlTokenClass,
};
use std::{
fs,
path::PathBuf,
time::{SystemTime, UNIX_EPOCH},
};

#[test]
fn indexes_lines() {
let offsets = Viewer::index_lines(b"a\nb\nlast");
assert_eq!(offsets, vec![0, 2, 4]);
}

#[test]
fn indexes_empty() {
let offsets = Viewer::index_lines(b"");
assert_eq!(offsets, vec![0]);
}

#[test]
fn centers_target_line_when_possible() {
assert_eq!(centered_top_line(50, 20, 200), 40);
}

#[test]
fn centers_target_line_with_small_targets() {
assert_eq!(centered_top_line(3, 20, 200), 0);
}

#[test]
fn centers_target_line_near_end() {
assert_eq!(centered_top_line(199, 20, 200), 189);
}

#[test]
fn finds_forward_and_backward() {
let viewer = test_viewer_from_bytes(b"abc\ndef abc xyz abc");
assert_eq!(viewer.find_forward(b"abc", 0), Some((0, 3)));
assert_eq!(viewer.find_forward(b"abc", 4), Some((8, 11)));
assert_eq!(viewer.find_backward(b"abc", 18), Some((16, 19)));
assert_eq!(viewer.find_backward(b"missing", 18), None);
}

#[test]
fn maps_offsets_to_lines() {
let viewer = test_viewer_from_bytes(b"line1\nline2\nline3");
assert_eq!(viewer.line_of_offset(0), 0);
assert_eq!(viewer.line_of_offset(6), 1);
assert_eq!(viewer.line_of_offset(12), 2);
}

fn with_temp_file(bytes: &[u8], f: impl FnOnce(PathBuf) -> Viewer) -> Viewer {
let nonce = SystemTime::now()
.duration_since(UNIX_EPOCH)
.expect("time went backwards")
.as_nanos();
let path = std::env::temp_dir().join(format!("large-file-viewer-test-{nonce}.txt"));
fs::write(&path, bytes).expect("failed to write temp file");
let viewer = f(path.clone());
fs::remove_file(path).expect("failed to remove temp file");
viewer
}

fn test_viewer_from_bytes(bytes: &[u8]) -> Viewer {
with_temp_file(bytes, |path| {
Viewer::open(path, 4, false, None, false, false, false).expect("failed to open viewer")
})
}

#[test]
fn indexes_csv_column_widths() {
let widths = Viewer::index_csv_column_widths(b"a,bbb\ncccc,d", 4, b',');
assert_eq!(widths, vec![4, 3]);
}

#[test]
fn csv_mode_starts_below_pinned_header() {
let viewer = test_viewer_with_options(b"h1,h2\nv1,v2\nv3,v4", 4, true);
assert_eq!(viewer.top_line, 1);
}

#[test]
fn csv_scroll_up_keeps_header_pinned() {
let mut viewer = test_viewer_with_options(b"h1,h2\nv1,v2\nv3,v4", 4, true);
viewer.scroll_up(10);
assert_eq!(viewer.top_line, 1);
}

#[test]
fn auto_detects_semicolon_separator() {
assert_eq!(detect_csv_separator(b"h1;h2\na;b\nc;d"), b';');
}

#[test]
fn parses_tab_separator_escape() {
assert_eq!(parse_csv_separator(r"\t").expect("should parse"), b'\t');
}

fn test_viewer_with_options(bytes: &[u8], tab_width: usize, csv: bool) -> Viewer {
with_temp_file(bytes, |path| {
Viewer::open(path, tab_width, csv, None, false, false, false)
.expect("failed to open viewer")
})
}

#[test]
fn classifies_xml_tags_and_attributes() {
let classes = classify_xml_line(br#"<node attr="value">text</node>"#);
assert_eq!(classes[0], XmlTokenClass::TagDelimiter);
assert_eq!(classes[1], XmlTokenClass::TagName);
assert_eq!(classes[6], XmlTokenClass::AttributeName);
assert_eq!(classes[11], XmlTokenClass::AttributeValue);
assert_eq!(classes[19], XmlTokenClass::Text);
}

#[test]
fn classifies_xml_comments() {
let classes = classify_xml_line(br#"<!-- comment --> <node/>"#);
assert_eq!(classes[0], XmlTokenClass::Comment);
assert_eq!(classes[10], XmlTokenClass::Comment);
assert_eq!(classes[16], XmlTokenClass::Text);
assert_eq!(classes[17], XmlTokenClass::TagDelimiter);
assert_eq!(classes[18], XmlTokenClass::TagName);
}

#[test]
fn skips_utf8_bom_prefix_on_first_line_only() {
let bom_prefixed = [0xEF_u8, 0xBB_u8, 0xBF_u8, b'<', b'x', b'>'];
assert_eq!(skipped_prefix_len(0, &bom_prefixed), 3);
assert_eq!(skipped_prefix_len(1, &bom_prefixed), 0);
assert_eq!(skipped_prefix_len(0, b"<x>"), 0);
}

#[test]
fn classifies_json_tokens() {
let json = br#"{"name":"bob","age":42,"ok":true,"v":null}"#;
let classes = classify_json_line(json);

let first_colon = json
.iter()
.position(|&b| b == b':')
.expect("json should contain colon");
let age_index = json
.windows(3)
.position(|w| w == b"age")
.expect("json should contain age");
let number_index = json
.iter()
.position(|&b| b == b'4')
.expect("json should contain number");
let true_index = json
.windows(4)
.position(|w| w == b"true")
.expect("json should contain true");
let null_index = json
.windows(4)
.position(|w| w == b"null")
.expect("json should contain null");

assert_eq!(classes[0], JsonTokenClass::Delimiter);
assert_eq!(classes[1], JsonTokenClass::Key);
assert_eq!(classes[first_colon], JsonTokenClass::Delimiter);
assert_eq!(classes[age_index], JsonTokenClass::Key);
assert_eq!(classes[number_index], JsonTokenClass::Number);
assert_eq!(classes[true_index], JsonTokenClass::Keyword);
assert_eq!(classes[null_index], JsonTokenClass::Keyword);
}

#[test]
fn formats_single_line_xml_into_indented_lines() {
let xml = br#"<root><parent><child/></parent><value>text</value></root>"#;
let formatted = format_xml_for_display(xml);
let formatted = String::from_utf8(formatted).expect("formatted xml should be utf8");
let expected =
"<root>\n <parent>\n <child/>\n </parent>\n <value>text</value>\n</root>";
assert_eq!(formatted, expected);
}

#[test]
fn formats_xml_with_comments_and_header() {
let xml = br#"<?xml version="1.0"?><root><!-- comment --><node/></root>"#;
let formatted = format_xml_for_display(xml);
let formatted = String::from_utf8(formatted).expect("formatted xml should be utf8");
let expected = "<?xml version=\"1.0\"?>\n<root>\n <!-- comment -->\n <node/>\n</root>";
assert_eq!(formatted, expected);
}

#[test]
fn formats_json_into_pretty_lines() {
let json = br#"{"item":"Test","count":2,"ok":true,"arr":[1,2]}"#;
let formatted = format_json_for_display(json).expect("json should format");
let formatted = String::from_utf8(formatted).expect("formatted json should be utf8");
let expected = "{\n \"item\": \"Test\",\n \"count\": 2,\n \"ok\": true,\n \"arr\": [\n 1,\n 2\n ]\n}";
assert_eq!(formatted, expected);
}

#[test]
fn invalid_json_does_not_format() {
assert!(format_json_for_display(br#"{"bad":"unterminated}"#).is_none());
}
}
mod tests;
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