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Diffstat (limited to 'crates/atuin-ai/src/diff.rs')
| -rw-r--r-- | crates/atuin-ai/src/diff.rs | 328 |
1 files changed, 0 insertions, 328 deletions
diff --git a/crates/atuin-ai/src/diff.rs b/crates/atuin-ai/src/diff.rs deleted file mode 100644 index e704175c..00000000 --- a/crates/atuin-ai/src/diff.rs +++ /dev/null @@ -1,328 +0,0 @@ -//! Structured diff computation for edit previews. -//! -//! Computes a line-level diff between old and new file content using -//! imara-diff's Histogram algorithm, producing structured hunks with -//! typed lines (Context, Added, Removed) suitable for TUI rendering. - -use imara_diff::{Algorithm, Diff, InternedInput}; - -/// Number of context lines to show around each change. -const CONTEXT_LINES: u32 = 3; - -/// A structured diff preview for a file edit, ready for rendering. -#[derive(Debug, Clone)] -pub(crate) struct EditPreview { - pub hunks: Vec<DiffHunk>, -} - -/// A contiguous group of diff lines (context + changes). -#[derive(Debug, Clone)] -pub(crate) struct DiffHunk { - /// 1-indexed line number of the first line in this hunk (in the original file). - pub before_start: u32, - /// 1-indexed line number of the first line in this hunk (in the new file). - pub after_start: u32, - pub lines: Vec<DiffLine>, -} - -/// A single line in a diff hunk. -#[derive(Debug, Clone, PartialEq, Eq)] -pub(crate) enum DiffLine { - /// Unchanged line (shown for context). - Context(String), - /// Line added in the new version. - Added(String), - /// Line removed from the old version. - Removed(String), -} - -impl EditPreview { - /// Compute a structured diff between old and new file content. - /// - /// Uses the Histogram algorithm with line-level granularity and - /// indentation-aware postprocessing for readable output. - pub fn compute(old: &str, new: &str) -> Self { - let input = InternedInput::new(old, new); - let mut diff = Diff::compute(Algorithm::Histogram, &input); - diff.postprocess_lines(&input); - - let raw_hunks: Vec<_> = diff.hunks().collect(); - if raw_hunks.is_empty() { - return EditPreview { hunks: Vec::new() }; - } - - // Merge hunks that are within 2*CONTEXT_LINES of each other - // (same logic as unified diff format). - let mut merged_groups: Vec<Vec<&imara_diff::Hunk>> = Vec::new(); - let mut current_group: Vec<&imara_diff::Hunk> = vec![&raw_hunks[0]]; - - for hunk in &raw_hunks[1..] { - let prev = current_group.last().unwrap(); - if hunk.before.start.saturating_sub(prev.before.end) <= 2 * CONTEXT_LINES { - current_group.push(hunk); - } else { - merged_groups.push(current_group); - current_group = vec![hunk]; - } - } - merged_groups.push(current_group); - - // Build structured hunks from merged groups - let hunks = merged_groups - .into_iter() - .map(|group| build_hunk(&group, &input)) - .collect(); - - EditPreview { hunks } - } - - /// The highest line number (from either file) that will be displayed. - /// Used to calculate gutter width. - pub fn max_line_number(&self) -> u32 { - self.hunks - .iter() - .map(|h| { - let mut before_pos = h.before_start; - let mut after_pos = h.after_start; - for line in &h.lines { - match line { - DiffLine::Context(_) => { - before_pos += 1; - after_pos += 1; - } - DiffLine::Removed(_) => before_pos += 1, - DiffLine::Added(_) => after_pos += 1, - } - } - before_pos.max(after_pos).saturating_sub(1) - }) - .max() - .unwrap_or(0) - } -} - -/// Maximum lines to show in a write preview. -const WRITE_PREVIEW_LINES: usize = 10; - -/// A content preview for a write_file operation. -/// -/// Shows the first N lines of the written content plus a count of -/// remaining lines if truncated. -#[derive(Debug, Clone)] -pub(crate) struct WritePreview { - /// First lines of content (up to WRITE_PREVIEW_LINES). - pub lines: Vec<String>, - /// Total number of lines in the written file. - pub total_lines: usize, -} - -impl WritePreview { - /// Create a preview from file content. - pub fn from_content(content: &str) -> Self { - let all_lines: Vec<&str> = content.lines().collect(); - let total_lines = all_lines.len(); - let lines = all_lines - .into_iter() - .take(WRITE_PREVIEW_LINES) - .map(String::from) - .collect(); - WritePreview { lines, total_lines } - } - - /// Number of lines not shown in the preview. - pub fn remaining_lines(&self) -> usize { - self.total_lines.saturating_sub(self.lines.len()) - } -} - -/// Build a single DiffHunk from a group of adjacent raw hunks. -fn build_hunk(group: &[&imara_diff::Hunk], input: &InternedInput<&str>) -> DiffHunk { - let first = group.first().unwrap(); - let last = group.last().unwrap(); - - let context_start = first.before.start.saturating_sub(CONTEXT_LINES); - let context_end = (last.before.end + CONTEXT_LINES).min(input.before.len() as u32); - - // The after-file position of context_start: same offset as before since - // context before the first change is identical in both files. - let after_context_start = first.after.start - (first.before.start - context_start); - - let mut lines = Vec::new(); - let mut pos = context_start; - - for hunk in group { - // Context lines before this hunk - for i in pos..hunk.before.start { - lines.push(DiffLine::Context(token_text(input, true, i))); - } - - // Removed lines - for i in hunk.before.start..hunk.before.end { - lines.push(DiffLine::Removed(token_text(input, true, i))); - } - - // Added lines - for i in hunk.after.start..hunk.after.end { - lines.push(DiffLine::Added(token_text(input, false, i))); - } - - pos = hunk.before.end; - } - - // Trailing context - for i in pos..context_end { - lines.push(DiffLine::Context(token_text(input, true, i))); - } - - DiffHunk { - before_start: context_start + 1, // 1-indexed - after_start: after_context_start + 1, // 1-indexed - lines, - } -} - -/// Extract the text content of a token, trimming the trailing newline -/// that imara-diff includes in line-based tokenization. -fn token_text(input: &InternedInput<&str>, is_before: bool, idx: u32) -> String { - let tokens = if is_before { - &input.before - } else { - &input.after - }; - let text = input.interner[tokens[idx as usize]]; - text.strip_suffix('\n') - .unwrap_or(text) - .strip_suffix('\r') - .unwrap_or(text.strip_suffix('\n').unwrap_or(text)) - .to_string() -} - -#[cfg(test)] -mod tests { - use super::*; - - #[test] - fn no_changes_produces_empty_preview() { - let preview = EditPreview::compute("hello\nworld\n", "hello\nworld\n"); - assert!(preview.hunks.is_empty()); - } - - #[test] - fn single_line_replacement() { - let old = "line1\nline2\nline3\n"; - let new = "line1\nchanged\nline3\n"; - let preview = EditPreview::compute(old, new); - - assert_eq!(preview.hunks.len(), 1); - let hunk = &preview.hunks[0]; - - // Should have: context(line1), removed(line2), added(changed), context(line3) - assert!(hunk.lines.contains(&DiffLine::Context("line1".into()))); - assert!(hunk.lines.contains(&DiffLine::Removed("line2".into()))); - assert!(hunk.lines.contains(&DiffLine::Added("changed".into()))); - assert!(hunk.lines.contains(&DiffLine::Context("line3".into()))); - } - - #[test] - fn addition_only() { - let old = "aaa\nbbb\n"; - let new = "aaa\nnew_line\nbbb\n"; - let preview = EditPreview::compute(old, new); - - assert_eq!(preview.hunks.len(), 1); - let hunk = &preview.hunks[0]; - assert!(hunk.lines.contains(&DiffLine::Added("new_line".into()))); - // Original lines are context - assert!(hunk.lines.contains(&DiffLine::Context("aaa".into()))); - assert!(hunk.lines.contains(&DiffLine::Context("bbb".into()))); - } - - #[test] - fn removal_only() { - let old = "aaa\nremove_me\nbbb\n"; - let new = "aaa\nbbb\n"; - let preview = EditPreview::compute(old, new); - - assert_eq!(preview.hunks.len(), 1); - let hunk = &preview.hunks[0]; - assert!(hunk.lines.contains(&DiffLine::Removed("remove_me".into()))); - } - - #[test] - fn distant_changes_produce_separate_hunks() { - // Two changes separated by more than 2*CONTEXT_LINES (6) lines - let old = "1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n11\n12\n"; - let new = "1\nX\n3\n4\n5\n6\n7\n8\n9\n10\n11\nY\n"; - let preview = EditPreview::compute(old, new); - - assert_eq!(preview.hunks.len(), 2); - } - - #[test] - fn close_changes_merge_into_one_hunk() { - // Two changes separated by fewer than 2*CONTEXT_LINES lines - let old = "1\n2\n3\n4\n5\n"; - let new = "X\n2\n3\n4\nY\n"; - let preview = EditPreview::compute(old, new); - - assert_eq!(preview.hunks.len(), 1); - } - - #[test] - fn context_is_limited() { - // With CONTEXT_LINES=3, a change at line 10 shouldn't include line 1 - let mut old_lines: Vec<&str> = (1..=20).map(|_| "unchanged").collect(); - old_lines[9] = "target"; - let old = old_lines.join("\n") + "\n"; - let new = old.replace("target", "replaced"); - - let preview = EditPreview::compute(&old, &new); - assert_eq!(preview.hunks.len(), 1); - - // Should have at most 3 context lines before + 3 after + 1 removed + 1 added = 8 lines - assert!(preview.hunks[0].lines.len() <= 8); - } - - #[test] - fn max_line_number_reflects_file_position() { - let old = "a\nb\nc\n"; - let new = "a\nX\nc\n"; - let preview = EditPreview::compute(old, new); - // 3-line file, context + removed lines span positions 1-3 - assert_eq!(preview.max_line_number(), 3); - } - - #[test] - fn start_line_is_correct_for_later_changes() { - // Change at line 10 with 3 context lines → before_start = 7 - let mut lines: Vec<String> = (1..=15).map(|i| format!("line{i}")).collect(); - let old = lines.join("\n") + "\n"; - lines[9] = "CHANGED".to_string(); - let new = lines.join("\n") + "\n"; - - let preview = EditPreview::compute(&old, &new); - assert_eq!(preview.hunks.len(), 1); - assert_eq!(preview.hunks[0].before_start, 7); // line 10 - 3 context = line 7 - assert_eq!(preview.hunks[0].after_start, 7); // same for a simple replacement - } - - #[test] - fn multiline_replacement() { - let old = "[section]\nkey1 = old1\nkey2 = old2\n[other]\n"; - let new = "[section]\nkey1 = new1\nkey2 = new2\n[other]\n"; - let preview = EditPreview::compute(old, new); - - assert_eq!(preview.hunks.len(), 1); - let hunk = &preview.hunks[0]; - assert!( - hunk.lines - .contains(&DiffLine::Removed("key1 = old1".into())) - ); - assert!( - hunk.lines - .contains(&DiffLine::Removed("key2 = old2".into())) - ); - assert!(hunk.lines.contains(&DiffLine::Added("key1 = new1".into()))); - assert!(hunk.lines.contains(&DiffLine::Added("key2 = new2".into()))); - } -} |