feat(tui2): copy tui crate and normalize snapshots (#7833)

Introduce a full codex-tui source snapshot under the new codex-tui2
crate so viewport work can be replayed in isolation.

This change copies the entire codex-rs/tui/src tree into
codex-rs/tui2/src in one atomic step, rather than piecemeal, to keep
future diffs vs the original viewport bookmark easy to reason about.

The goal is for codex-tui2 to render identically to the existing TUI
behind the `features.tui2` flag while we gradually port the
viewport/history commits from the joshka/viewport bookmark onto this
forked tree.

While on this baseline change, we also ran the codex-tui2 snapshot test
suite and accepted all insta snapshots for the new crate, so the
snapshot files now use the codex-tui2 naming scheme and encode the
unmodified legacy TUI behavior. This keeps later viewport commits
focused on intentional behavior changes (and their snapshots) rather
than on mechanical snapshot renames.

codex-rs/tui2/src/text_formatting.rs

@@ -0,0 +1,525 @@
+use unicode_segmentation::UnicodeSegmentation;
+use unicode_width::UnicodeWidthChar;
+use unicode_width::UnicodeWidthStr;
+
+/// Truncate a tool result to fit within the given height and width. If the text is valid JSON, we format it in a compact way before truncating.
+/// This is a best-effort approach that may not work perfectly for text where 1 grapheme is rendered as multiple terminal cells.
+pub(crate) fn format_and_truncate_tool_result(
+    text: &str,
+    max_lines: usize,
+    line_width: usize,
+) -> String {
+    // Work out the maximum number of graphemes we can display for a result.
+    // It's not guaranteed that 1 grapheme = 1 cell, so we subtract 1 per line as a fudge factor.
+    // It also won't handle future terminal resizes properly, but it's an OK approximation for now.
+    let max_graphemes = (max_lines * line_width).saturating_sub(max_lines);
+
+    if let Some(formatted_json) = format_json_compact(text) {
+        truncate_text(&formatted_json, max_graphemes)
+    } else {
+        truncate_text(text, max_graphemes)
+    }
+}
+
+/// Format JSON text in a compact single-line format with spaces for better Ratatui wrapping.
+/// Ex: `{"a":"b",c:["d","e"]}` -> `{"a": "b", "c": ["d", "e"]}`
+/// Returns the formatted JSON string if the input is valid JSON, otherwise returns None.
+/// This is a little complicated, but it's necessary because Ratatui's wrapping is *very* limited
+/// and can only do line breaks at whitespace. If we use the default serde_json format, we get lines
+/// without spaces that Ratatui can't wrap nicely. If we use the serde_json pretty format as-is,
+/// it's much too sparse and uses too many terminal rows.
+/// Relevant issue: https://github.com/ratatui/ratatui/issues/293
+pub(crate) fn format_json_compact(text: &str) -> Option<String> {
+    let json = serde_json::from_str::<serde_json::Value>(text).ok()?;
+    let json_pretty = serde_json::to_string_pretty(&json).unwrap_or_else(|_| json.to_string());
+
+    // Convert multi-line pretty JSON to compact single-line format by removing newlines and excess whitespace
+    let mut result = String::new();
+    let mut chars = json_pretty.chars().peekable();
+    let mut in_string = false;
+    let mut escape_next = false;
+
+    // Iterate over the characters in the JSON string, adding spaces after : and , but only when not in a string
+    while let Some(ch) = chars.next() {
+        match ch {
+            '"' if !escape_next => {
+                in_string = !in_string;
+                result.push(ch);
+            }
+            '\\' if in_string => {
+                escape_next = !escape_next;
+                result.push(ch);
+            }
+            '\n' | '\r' if !in_string => {
+                // Skip newlines when not in a string
+            }
+            ' ' | '\t' if !in_string => {
+                // Add a space after : and , but only when not in a string
+                if let Some(&next_ch) = chars.peek()
+                    && let Some(last_ch) = result.chars().last()
+                    && (last_ch == ':' || last_ch == ',')
+                    && !matches!(next_ch, '}' | ']')
+                {
+                    result.push(' ');
+                }
+            }
+            _ => {
+                if escape_next && in_string {
+                    escape_next = false;
+                }
+                result.push(ch);
+            }
+        }
+    }
+
+    Some(result)
+}
+
+/// Truncate `text` to `max_graphemes` graphemes. Using graphemes to avoid accidentally truncating in the middle of a multi-codepoint character.
+pub(crate) fn truncate_text(text: &str, max_graphemes: usize) -> String {
+    let mut graphemes = text.grapheme_indices(true);
+
+    // Check if there's a grapheme at position max_graphemes (meaning there are more than max_graphemes total)
+    if let Some((byte_index, _)) = graphemes.nth(max_graphemes) {
+        // There are more than max_graphemes, so we need to truncate
+        if max_graphemes >= 3 {
+            // Truncate to max_graphemes - 3 and add "..." to stay within limit
+            let mut truncate_graphemes = text.grapheme_indices(true);
+            if let Some((truncate_byte_index, _)) = truncate_graphemes.nth(max_graphemes - 3) {
+                let truncated = &text[..truncate_byte_index];
+                format!("{truncated}...")
+            } else {
+                text.to_string()
+            }
+        } else {
+            // max_graphemes < 3, so just return first max_graphemes without "..."
+            let truncated = &text[..byte_index];
+            truncated.to_string()
+        }
+    } else {
+        // There are max_graphemes or fewer graphemes, return original text
+        text.to_string()
+    }
+}
+
+/// Truncate a path-like string to the given display width, keeping leading and trailing segments
+/// where possible and inserting a single Unicode ellipsis between them. If an individual segment
+/// cannot fit, it is front-truncated with an ellipsis.
+pub(crate) fn center_truncate_path(path: &str, max_width: usize) -> String {
+    if max_width == 0 {
+        return String::new();
+    }
+    if UnicodeWidthStr::width(path) <= max_width {
+        return path.to_string();
+    }
+
+    let sep = std::path::MAIN_SEPARATOR;
+    let has_leading_sep = path.starts_with(sep);
+    let has_trailing_sep = path.ends_with(sep);
+    let mut raw_segments: Vec<&str> = path.split(sep).collect();
+    if has_leading_sep && !raw_segments.is_empty() && raw_segments[0].is_empty() {
+        raw_segments.remove(0);
+    }
+    if has_trailing_sep
+        && !raw_segments.is_empty()
+        && raw_segments.last().is_some_and(|last| last.is_empty())
+    {
+        raw_segments.pop();
+    }
+
+    if raw_segments.is_empty() {
+        if has_leading_sep {
+            let root = sep.to_string();
+            if UnicodeWidthStr::width(root.as_str()) <= max_width {
+                return root;
+            }
+        }
+        return "…".to_string();
+    }
+
+    struct Segment<'a> {
+        original: &'a str,
+        text: String,
+        truncatable: bool,
+        is_suffix: bool,
+    }
+
+    let assemble = |leading: bool, segments: &[Segment<'_>]| -> String {
+        let mut result = String::new();
+        if leading {
+            result.push(sep);
+        }
+        for segment in segments {
+            if !result.is_empty() && !result.ends_with(sep) {
+                result.push(sep);
+            }
+            result.push_str(segment.text.as_str());
+        }
+        result
+    };
+
+    let front_truncate = |original: &str, allowed_width: usize| -> String {
+        if allowed_width == 0 {
+            return String::new();
+        }
+        if UnicodeWidthStr::width(original) <= allowed_width {
+            return original.to_string();
+        }
+        if allowed_width == 1 {
+            return "…".to_string();
+        }
+
+        let mut kept: Vec<char> = Vec::new();
+        let mut used_width = 1; // reserve space for leading ellipsis
+        for ch in original.chars().rev() {
+            let ch_width = UnicodeWidthChar::width(ch).unwrap_or(0);
+            if used_width + ch_width > allowed_width {
+                break;
+            }
+            used_width += ch_width;
+            kept.push(ch);
+        }
+        kept.reverse();
+        let mut truncated = String::from("…");
+        for ch in kept {
+            truncated.push(ch);
+        }
+        truncated
+    };
+
+    let mut combos: Vec<(usize, usize)> = Vec::new();
+    let segment_count = raw_segments.len();
+    for left in 1..=segment_count {
+        let min_right = if left == segment_count { 0 } else { 1 };
+        for right in min_right..=(segment_count - left) {
+            combos.push((left, right));
+        }
+    }
+    let desired_suffix = if segment_count > 1 {
+        std::cmp::min(2, segment_count - 1)
+    } else {
+        0
+    };
+    let mut prioritized: Vec<(usize, usize)> = Vec::new();
+    let mut fallback: Vec<(usize, usize)> = Vec::new();
+    for combo in combos {
+        if combo.1 >= desired_suffix {
+            prioritized.push(combo);
+        } else {
+            fallback.push(combo);
+        }
+    }
+    let sort_combos = |items: &mut Vec<(usize, usize)>| {
+        items.sort_by(|(left_a, right_a), (left_b, right_b)| {
+            left_b
+                .cmp(left_a)
+                .then_with(|| right_b.cmp(right_a))
+                .then_with(|| (left_b + right_b).cmp(&(left_a + right_a)))
+        });
+    };
+    sort_combos(&mut prioritized);
+    sort_combos(&mut fallback);
+
+    let fit_segments =
+        |segments: &mut Vec<Segment<'_>>, allow_front_truncate: bool| -> Option<String> {
+            loop {
+                let candidate = assemble(has_leading_sep, segments);
+                let width = UnicodeWidthStr::width(candidate.as_str());
+                if width <= max_width {
+                    return Some(candidate);
+                }
+
+                if !allow_front_truncate {
+                    return None;
+                }
+
+                let mut indices: Vec<usize> = Vec::new();
+                for (idx, seg) in segments.iter().enumerate().rev() {
+                    if seg.truncatable && seg.is_suffix {
+                        indices.push(idx);
+                    }
+                }
+                for (idx, seg) in segments.iter().enumerate().rev() {
+                    if seg.truncatable && !seg.is_suffix {
+                        indices.push(idx);
+                    }
+                }
+
+                if indices.is_empty() {
+                    return None;
+                }
+
+                let mut changed = false;
+                for idx in indices {
+                    let original_width = UnicodeWidthStr::width(segments[idx].original);
+                    if original_width <= max_width && segment_count > 2 {
+                        continue;
+                    }
+                    let seg_width = UnicodeWidthStr::width(segments[idx].text.as_str());
+                    let other_width = width.saturating_sub(seg_width);
+                    let allowed_width = max_width.saturating_sub(other_width).max(1);
+                    let new_text = front_truncate(segments[idx].original, allowed_width);
+                    if new_text != segments[idx].text {
+                        segments[idx].text = new_text;
+                        changed = true;
+                        break;
+                    }
+                }
+
+                if !changed {
+                    return None;
+                }
+            }
+        };
+
+    for (left_count, right_count) in prioritized.into_iter().chain(fallback.into_iter()) {
+        let mut segments: Vec<Segment<'_>> = raw_segments[..left_count]
+            .iter()
+            .map(|seg| Segment {
+                original: seg,
+                text: (*seg).to_string(),
+                truncatable: true,
+                is_suffix: false,
+            })
+            .collect();
+
+        let need_ellipsis = left_count + right_count < segment_count;
+        if need_ellipsis {
+            segments.push(Segment {
+                original: "…",
+                text: "…".to_string(),
+                truncatable: false,
+                is_suffix: false,
+            });
+        }
+
+        if right_count > 0 {
+            segments.extend(
+                raw_segments[segment_count - right_count..]
+                    .iter()
+                    .map(|seg| Segment {
+                        original: seg,
+                        text: (*seg).to_string(),
+                        truncatable: true,
+                        is_suffix: true,
+                    }),
+            );
+        }
+
+        let allow_front_truncate = need_ellipsis || segment_count <= 2;
+        if let Some(candidate) = fit_segments(&mut segments, allow_front_truncate) {
+            return candidate;
+        }
+    }
+
+    front_truncate(path, max_width)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use pretty_assertions::assert_eq;
+
+    #[test]
+    fn test_truncate_text() {
+        let text = "Hello, world!";
+        let truncated = truncate_text(text, 8);
+        assert_eq!(truncated, "Hello...");
+    }
+
+    #[test]
+    fn test_truncate_empty_string() {
+        let text = "";
+        let truncated = truncate_text(text, 5);
+        assert_eq!(truncated, "");
+    }
+
+    #[test]
+    fn test_truncate_max_graphemes_zero() {
+        let text = "Hello";
+        let truncated = truncate_text(text, 0);
+        assert_eq!(truncated, "");
+    }
+
+    #[test]
+    fn test_truncate_max_graphemes_one() {
+        let text = "Hello";
+        let truncated = truncate_text(text, 1);
+        assert_eq!(truncated, "H");
+    }
+
+    #[test]
+    fn test_truncate_max_graphemes_two() {
+        let text = "Hello";
+        let truncated = truncate_text(text, 2);
+        assert_eq!(truncated, "He");
+    }
+
+    #[test]
+    fn test_truncate_max_graphemes_three_boundary() {
+        let text = "Hello";
+        let truncated = truncate_text(text, 3);
+        assert_eq!(truncated, "...");
+    }
+
+    #[test]
+    fn test_truncate_text_shorter_than_limit() {
+        let text = "Hi";
+        let truncated = truncate_text(text, 10);
+        assert_eq!(truncated, "Hi");
+    }
+
+    #[test]
+    fn test_truncate_text_exact_length() {
+        let text = "Hello";
+        let truncated = truncate_text(text, 5);
+        assert_eq!(truncated, "Hello");
+    }
+
+    #[test]
+    fn test_truncate_emoji() {
+        let text = "👋🌍🚀✨💫";
+        let truncated = truncate_text(text, 3);
+        assert_eq!(truncated, "...");
+
+        let truncated_longer = truncate_text(text, 4);
+        assert_eq!(truncated_longer, "👋...");
+    }
+
+    #[test]
+    fn test_truncate_unicode_combining_characters() {
+        let text = "é́ñ̃"; // Characters with combining marks
+        let truncated = truncate_text(text, 2);
+        assert_eq!(truncated, "é́ñ̃");
+    }
+
+    #[test]
+    fn test_truncate_very_long_text() {
+        let text = "a".repeat(1000);
+        let truncated = truncate_text(&text, 10);
+        assert_eq!(truncated, "aaaaaaa...");
+        assert_eq!(truncated.len(), 10); // 7 'a's + 3 dots
+    }
+
+    #[test]
+    fn test_format_json_compact_simple_object() {
+        let json = r#"{ "name": "John", "age": 30 }"#;
+        let result = format_json_compact(json).unwrap();
+        assert_eq!(result, r#"{"name": "John", "age": 30}"#);
+    }
+
+    #[test]
+    fn test_format_json_compact_nested_object() {
+        let json = r#"{ "user": { "name": "John", "details": { "age": 30, "city": "NYC" } } }"#;
+        let result = format_json_compact(json).unwrap();
+        assert_eq!(
+            result,
+            r#"{"user": {"name": "John", "details": {"age": 30, "city": "NYC"}}}"#
+        );
+    }
+
+    #[test]
+    fn test_center_truncate_doesnt_truncate_short_path() {
+        let sep = std::path::MAIN_SEPARATOR;
+        let path = format!("{sep}Users{sep}codex{sep}Public");
+        let truncated = center_truncate_path(&path, 40);
+
+        assert_eq!(truncated, path);
+    }
+
+    #[test]
+    fn test_center_truncate_truncates_long_path() {
+        let sep = std::path::MAIN_SEPARATOR;
+        let path = format!("~{sep}hello{sep}the{sep}fox{sep}is{sep}very{sep}fast");
+        let truncated = center_truncate_path(&path, 24);
+
+        assert_eq!(
+            truncated,
+            format!("~{sep}hello{sep}the{sep}…{sep}very{sep}fast")
+        );
+    }
+
+    #[test]
+    fn test_center_truncate_truncates_long_windows_path() {
+        let sep = std::path::MAIN_SEPARATOR;
+        let path = format!(
+            "C:{sep}Users{sep}codex{sep}Projects{sep}super{sep}long{sep}windows{sep}path{sep}file.txt"
+        );
+        let truncated = center_truncate_path(&path, 36);
+
+        let expected = format!("C:{sep}Users{sep}codex{sep}…{sep}path{sep}file.txt");
+
+        assert_eq!(truncated, expected);
+    }
+
+    #[test]
+    fn test_center_truncate_handles_long_segment() {
+        let sep = std::path::MAIN_SEPARATOR;
+        let path = format!("~{sep}supercalifragilisticexpialidocious");
+        let truncated = center_truncate_path(&path, 18);
+
+        assert_eq!(truncated, format!("~{sep}…cexpialidocious"));
+    }
+
+    #[test]
+    fn test_format_json_compact_array() {
+        let json = r#"[ 1, 2, { "key": "value" }, "string" ]"#;
+        let result = format_json_compact(json).unwrap();
+        assert_eq!(result, r#"[1, 2, {"key": "value"}, "string"]"#);
+    }
+
+    #[test]
+    fn test_format_json_compact_already_compact() {
+        let json = r#"{"compact":true}"#;
+        let result = format_json_compact(json).unwrap();
+        assert_eq!(result, r#"{"compact": true}"#);
+    }
+
+    #[test]
+    fn test_format_json_compact_with_whitespace() {
+        let json = r#"
+        {
+            "name": "John",
+            "hobbies": [
+                "reading",
+                "coding"
+            ]
+        }
+        "#;
+        let result = format_json_compact(json).unwrap();
+        assert_eq!(
+            result,
+            r#"{"name": "John", "hobbies": ["reading", "coding"]}"#
+        );
+    }
+
+    #[test]
+    fn test_format_json_compact_invalid_json() {
+        let invalid_json = r#"{"invalid": json syntax}"#;
+        let result = format_json_compact(invalid_json);
+        assert!(result.is_none());
+    }
+
+    #[test]
+    fn test_format_json_compact_empty_object() {
+        let json = r#"{}"#;
+        let result = format_json_compact(json).unwrap();
+        assert_eq!(result, "{}");
+    }
+
+    #[test]
+    fn test_format_json_compact_empty_array() {
+        let json = r#"[]"#;
+        let result = format_json_compact(json).unwrap();
+        assert_eq!(result, "[]");
+    }
+
+    #[test]
+    fn test_format_json_compact_primitive_values() {
+        assert_eq!(format_json_compact("42").unwrap(), "42");
+        assert_eq!(format_json_compact("true").unwrap(), "true");
+        assert_eq!(format_json_compact("false").unwrap(), "false");
+        assert_eq!(format_json_compact("null").unwrap(), "null");
+        assert_eq!(format_json_compact(r#""string""#).unwrap(), r#""string""#);
+    }
+}