format_prompt.rs

  1use crate::{
  2    FormatPromptArgs, PredictionProvider,
  3    example::{ActualCursor, Example, ExamplePrompt},
  4    headless::EpAppState,
  5    progress::{ExampleProgress, Step},
  6    retrieve_context::run_context_retrieval,
  7};
  8use anyhow::{Context as _, Result, anyhow};
  9use edit_prediction::{cursor_excerpt::editable_and_context_ranges_for_cursor_position, udiff};
 10use gpui::{AppContext, AsyncApp};
 11use language::{Buffer, OffsetRangeExt, Point};
 12use similar::DiffableStr;
 13use std::sync::Arc;
 14use std::{fmt::Write as _, ops::Range};
 15use zeta_prompt::ZetaFormat;
 16use zeta_prompt::format_zeta_prompt;
 17
 18pub async fn run_format_prompt(
 19    example: &mut Example,
 20    args: &FormatPromptArgs,
 21    app_state: Arc<EpAppState>,
 22    example_progress: &ExampleProgress,
 23    cx: AsyncApp,
 24) -> Result<()> {
 25    run_context_retrieval(example, app_state.clone(), example_progress, cx.clone()).await?;
 26
 27    let step_progress = example_progress.start(Step::FormatPrompt);
 28
 29    let prompt_inputs = example
 30        .prompt_inputs
 31        .as_ref()
 32        .context("prompt_inputs must be set after context retrieval")?;
 33
 34    let language = app_state
 35        .languages
 36        .load_language_for_file_path(&example.spec.cursor_path)
 37        .await
 38        .ok();
 39    let snapshot_fut = cx.update(|cx| {
 40        Buffer::build_snapshot(
 41            prompt_inputs.content.as_str().into(),
 42            language,
 43            Some(app_state.languages.clone()),
 44            cx,
 45        )
 46    });
 47    let cursor_point = Point::new(prompt_inputs.cursor_row, prompt_inputs.cursor_column);
 48    let snapshot = cx.background_spawn(snapshot_fut).await;
 49
 50    match args.provider {
 51        PredictionProvider::Teacher(_) | PredictionProvider::TeacherNonBatching(_) => {
 52            step_progress.set_substatus("formatting teacher prompt");
 53
 54            let (editable_range, context_range) = editable_and_context_ranges_for_cursor_position(
 55                cursor_point,
 56                &snapshot,
 57                edit_prediction::zeta2::max_editable_tokens(ZetaFormat::default()),
 58                edit_prediction::zeta2::MAX_CONTEXT_TOKENS,
 59            );
 60            let editable_range = editable_range.to_offset(&snapshot);
 61            let context_range = context_range.to_offset(&snapshot);
 62
 63            let prompt = TeacherPrompt::format_prompt(example, editable_range, context_range);
 64            example.prompt = Some(ExamplePrompt {
 65                input: prompt,
 66                expected_output: String::new(),
 67                rejected_output: None,
 68                prefill: None,
 69                provider: args.provider,
 70            });
 71        }
 72        PredictionProvider::Zeta2(version) => {
 73            step_progress.set_substatus("formatting zeta2 prompt");
 74
 75            let (editable_range, context_range) = editable_and_context_ranges_for_cursor_position(
 76                cursor_point,
 77                &snapshot,
 78                edit_prediction::zeta2::max_editable_tokens(version),
 79                edit_prediction::zeta2::MAX_CONTEXT_TOKENS,
 80            );
 81            let editable_range = editable_range.to_offset(&snapshot);
 82            let context_range = context_range.to_offset(&snapshot);
 83
 84            let context_start = context_range.start;
 85            let cursor_offset_in_excerpt = prompt_inputs.cursor_offset - context_start;
 86            let editable_range_in_excerpt =
 87                (editable_range.start - context_start)..(editable_range.end - context_start);
 88            let input = zeta_prompt::ZetaPromptInput {
 89                cursor_path: example.spec.cursor_path.clone(),
 90                cursor_excerpt: prompt_inputs.content[context_range].to_string().into(),
 91                editable_range_in_excerpt,
 92                cursor_offset_in_excerpt,
 93                excerpt_start_row: prompt_inputs.excerpt_start_row,
 94                events: prompt_inputs.edit_history.clone(),
 95                related_files: prompt_inputs.related_files.clone().unwrap_or_default(),
 96                excerpt_ranges: None,
 97                preferred_model: None,
 98                in_open_source_repo: example
 99                    .spec
100                    .captured_prompt_input
101                    .as_ref()
102                    .map_or(false, |input| input.in_open_source_repo),
103                can_collect_data: false,
104            };
105            let prompt = format_zeta_prompt(&input, version);
106            let prefill = zeta_prompt::get_prefill(&input, version);
107            let (expected_patch, expected_cursor_offset) = example
108                .spec
109                .expected_patches_with_cursor_positions()
110                .into_iter()
111                .next()
112                .context("expected patches is empty")?;
113            let expected_output =
114                zeta2_output_for_patch(&input, &expected_patch, expected_cursor_offset, version)?;
115            let rejected_output = example
116                .spec
117                .rejected_patch
118                .as_ref()
119                .and_then(|patch| zeta2_output_for_patch(&input, patch, None, version).ok());
120
121            example.prompt = Some(ExamplePrompt {
122                input: prompt,
123                expected_output,
124                rejected_output,
125                provider: args.provider,
126                prefill: Some(prefill),
127            });
128        }
129        _ => {
130            panic!("Cannot format prompt for {:?}", args.provider);
131        }
132    };
133    Ok(())
134}
135
136pub fn zeta2_output_for_patch(
137    input: &zeta_prompt::ZetaPromptInput,
138    patch: &str,
139    cursor_offset: Option<usize>,
140    version: ZetaFormat,
141) -> Result<String> {
142    let mut old_editable_region =
143        input.cursor_excerpt[input.editable_range_in_excerpt.clone()].to_string();
144
145    if !old_editable_region.ends_with_newline() {
146        old_editable_region.push('\n');
147    }
148
149    let (mut result, first_hunk_offset) =
150        udiff::apply_diff_to_string_with_hunk_offset(patch, &old_editable_region).with_context(
151            || {
152                format!(
153                    "Patch:\n```\n{}```\n\nEditable region:\n```\n{}```",
154                    patch, old_editable_region
155                )
156            },
157        )?;
158
159    if let Some(cursor_offset) = cursor_offset {
160        // The cursor_offset is relative to the start of the hunk's new text (context + additions).
161        // We need to add where the hunk context matched in the editable region to compute
162        // the actual cursor position in the result.
163        let hunk_start = first_hunk_offset.unwrap_or(0);
164        let offset = result.floor_char_boundary((hunk_start + cursor_offset).min(result.len()));
165        result.insert_str(offset, zeta_prompt::CURSOR_MARKER);
166    }
167
168    match version {
169        ZetaFormat::V0120GitMergeMarkers
170        | ZetaFormat::V0131GitMergeMarkersPrefix
171        | ZetaFormat::V0211SeedCoder => {
172            if !result.ends_with('\n') {
173                result.push('\n');
174            }
175            result.push_str(zeta_prompt::v0120_git_merge_markers::END_MARKER);
176        }
177        _ => (),
178    }
179
180    Ok(result)
181}
182
183pub struct TeacherPrompt;
184
185impl TeacherPrompt {
186    pub(crate) const EDITABLE_REGION_START: &str = "<|editable_region_start|>\n";
187    pub(crate) const EDITABLE_REGION_END: &str = "\n<|editable_region_end|>";
188    pub(crate) const USER_CURSOR_MARKER: &str = "<|user_cursor|>";
189    pub(crate) const NO_EDITS: &str = "NO_EDITS";
190
191    /// Truncate edit history to this number of last lines
192    const MAX_HISTORY_LINES: usize = 128;
193
194    pub fn format_prompt(
195        example: &Example,
196        editable_range: Range<usize>,
197        context_range: Range<usize>,
198    ) -> String {
199        let edit_history = Self::format_edit_history(&example.spec.edit_history);
200        let context = Self::format_context(example);
201        let cursor_excerpt = Self::format_cursor_excerpt(example, editable_range, context_range);
202
203        let prompt_template = crate::prompt_assets::get_prompt("teacher.md");
204        let prompt = prompt_template
205            .replace("{{context}}", &context)
206            .replace("{{edit_history}}", &edit_history)
207            .replace("{{cursor_excerpt}}", &cursor_excerpt);
208
209        prompt
210    }
211
212    pub fn parse(example: &Example, response: &str) -> Result<(String, Option<ActualCursor>)> {
213        // Check if the model indicated no edits are needed
214        if let Some(last_codeblock) = extract_last_codeblock(&response) {
215            if last_codeblock.trim() == Self::NO_EDITS {
216                return Ok((String::new(), None));
217            }
218        }
219
220        // Extract updated (new) editable region from the model response.
221        let new_editable_region = Self::extract_editable_region(&response)?;
222        let cursor_offset = new_editable_region.find(Self::USER_CURSOR_MARKER);
223        let mut new_editable_region = new_editable_region.replace(Self::USER_CURSOR_MARKER, "");
224        let old_editable_region = Self::extract_editable_region(
225            &example
226                .prompt
227                .as_ref()
228                .context("example prompt missing")?
229                .input,
230        )?
231        .replace(Self::USER_CURSOR_MARKER, "");
232
233        let prompt_inputs = example
234            .prompt_inputs
235            .as_ref()
236            .context("example is missing prompt inputs")?;
237
238        // Normalize leading newlines: if old starts with newline but new doesn't,
239        // prepend newline to new to preserve whitespace structure.
240        // This handles the case where the model drops the leading blank line.
241        if old_editable_region.starts_with('\n') && !new_editable_region.starts_with('\n') {
242            new_editable_region.insert(0, '\n');
243        }
244
245        let (editable_region_offset, _) = prompt_inputs
246            .content
247            .match_indices(&old_editable_region)
248            .min_by_key(|(index, _)| index.abs_diff(prompt_inputs.cursor_offset))
249            .context("editable region not found in prompt content")?;
250        let editable_region_start_line = prompt_inputs.content[..editable_region_offset]
251            .matches('\n')
252            .count();
253
254        // Use full context so cursor offset (relative to editable region start) aligns with diff content
255        let editable_region_lines = old_editable_region.lines().count() as u32;
256        let diff = language::unified_diff_with_context(
257            &old_editable_region,
258            &new_editable_region,
259            editable_region_start_line as u32,
260            editable_region_start_line as u32,
261            editable_region_lines,
262        );
263
264        let diff = indoc::formatdoc! {"
265            --- a/{path}
266            +++ b/{path}
267            {diff}",
268            path = example.spec.cursor_path.to_string_lossy(),
269            diff = diff,
270        };
271
272        let actual_cursor = cursor_offset.map(|editable_region_cursor_offset| {
273            ActualCursor::from_editable_region(
274                &example.spec.cursor_path,
275                editable_region_cursor_offset,
276                &new_editable_region,
277                &prompt_inputs.content,
278                editable_region_offset,
279                editable_region_start_line,
280            )
281        });
282
283        Ok((diff, actual_cursor))
284    }
285
286    fn format_edit_history(edit_history: &str) -> String {
287        // Strip comments ("garbage lines") from edit history
288        let lines = edit_history
289            .lines()
290            .filter(|&s| Self::is_udiff_content_line(s))
291            .collect::<Vec<_>>();
292
293        let history_lines = if lines.len() > Self::MAX_HISTORY_LINES {
294            &lines[lines.len() - Self::MAX_HISTORY_LINES..]
295        } else {
296            &lines
297        };
298
299        if history_lines.is_empty() {
300            return "(No edit history)".to_string();
301        }
302
303        history_lines.join("\n")
304    }
305
306    pub fn format_context(example: &Example) -> String {
307        let related_files = example
308            .prompt_inputs
309            .as_ref()
310            .and_then(|pi| pi.related_files.as_ref());
311
312        let Some(related_files) = related_files else {
313            return "(No context)".to_string();
314        };
315
316        if related_files.is_empty() {
317            return "(No context)".to_string();
318        }
319
320        let mut prompt = String::new();
321        for file in related_files {
322            let path_str = file.path.to_string_lossy();
323            writeln!(&mut prompt, "`````{path_str}").ok();
324
325            let mut prev_row = 0;
326            for excerpt in &file.excerpts {
327                if excerpt.row_range.start > prev_row {
328                    prompt.push_str("\n");
329                }
330                prompt.push_str(&excerpt.text);
331                prompt.push('\n');
332                prev_row = excerpt.row_range.end;
333            }
334            if prev_row < file.max_row {
335                prompt.push_str("\n");
336            }
337            prompt.push_str("\n`````\n");
338        }
339
340        prompt
341    }
342
343    fn format_cursor_excerpt(
344        example: &Example,
345        editable_range: Range<usize>,
346        context_range: Range<usize>,
347    ) -> String {
348        let mut result = String::new();
349
350        let prompt_inputs = example.prompt_inputs.as_ref().unwrap();
351
352        let path_str = example.spec.cursor_path.to_string_lossy();
353        result.push_str(&format!("`````{path_str}\n"));
354        result.push_str(&prompt_inputs.content[context_range.start..editable_range.start]);
355        result.push_str(Self::EDITABLE_REGION_START);
356        result.push_str(&prompt_inputs.content[editable_range.start..prompt_inputs.cursor_offset]);
357        result.push_str(Self::USER_CURSOR_MARKER);
358        result.push_str(&prompt_inputs.content[prompt_inputs.cursor_offset..editable_range.end]);
359        result.push_str(Self::EDITABLE_REGION_END);
360        result.push_str(&prompt_inputs.content[editable_range.end..context_range.end]);
361        result.push_str("\n`````");
362
363        result
364    }
365
366    pub fn extract_editable_region(text: &str) -> Result<String> {
367        let start = text
368            .rfind(Self::EDITABLE_REGION_START)
369            .map_or(0, |pos| pos + Self::EDITABLE_REGION_START.len());
370        let end = text.rfind(Self::EDITABLE_REGION_END).unwrap_or(text.len());
371
372        if start >= end {
373            return Err(anyhow!("Invalid editable region markers"));
374        }
375
376        let region = &text[start..end];
377        Ok(region.strip_suffix('\n').unwrap_or(region).to_string())
378    }
379
380    fn is_udiff_content_line(s: &str) -> bool {
381        s.starts_with("-")
382            || s.starts_with("+")
383            || s.starts_with(" ")
384            || s.starts_with("---")
385            || s.starts_with("+++")
386            || s.starts_with("@@")
387    }
388}
389
390/// Extract the cursor excerpt from an example.
391/// First tries to extract from an existing prompt, then falls back to constructing from prompt_inputs.
392pub fn extract_cursor_excerpt_from_example(example: &Example) -> Option<String> {
393    // If we have the original prompt, extract the cursor excerpt from it
394    if let Some(prompt) = &example.prompt {
395        // Find "# 3. Current File" section and extract the content
396        if let Some(start) = prompt.input.find("# 3. Current File") {
397            let content_start = prompt.input[start..].find('`').map(|i| start + i)?;
398            let backtick_count = prompt.input[content_start..]
399                .chars()
400                .take_while(|&c| c == '`')
401                .count();
402            let content_start = content_start + backtick_count;
403
404            // Find the path line and skip it
405            let newline_pos = prompt.input[content_start..].find('\n')?;
406            let text_start = content_start + newline_pos + 1;
407
408            // Find the closing backticks
409            let closing_pattern = "`".repeat(backtick_count);
410            let text_end = prompt.input[text_start..].find(&closing_pattern)?;
411            let cursor_excerpt = &prompt.input[text_start..text_start + text_end];
412
413            let path_str = example.spec.cursor_path.to_string_lossy();
414            return Some(format!("`````{path_str}\n{cursor_excerpt}`````"));
415        }
416    }
417
418    // Fallback: construct from prompt_inputs if available
419    let prompt_inputs = example.prompt_inputs.as_ref()?;
420    let content = &prompt_inputs.content;
421    let cursor_offset = prompt_inputs.cursor_offset;
422
423    // Simple fallback: just show content around cursor with markers
424    let path_str = example.spec.cursor_path.to_string_lossy();
425    let mut result = format!("`````{path_str}\n");
426    result.push_str(TeacherPrompt::EDITABLE_REGION_START);
427    result.push_str(&content[..cursor_offset]);
428    result.push_str(TeacherPrompt::USER_CURSOR_MARKER);
429    result.push_str(&content[cursor_offset..]);
430    result.push_str(TeacherPrompt::EDITABLE_REGION_END);
431    result.push_str("\n`````");
432
433    Some(result)
434}
435
436pub(crate) fn extract_last_codeblock(text: &str) -> Option<String> {
437    let lines: Vec<&str> = text.lines().collect();
438
439    // Search from the end for a closing fence (line containing only backticks, 3+)
440    let mut closing_line_idx = None;
441    let mut backtick_count = 0;
442
443    for i in (0..lines.len()).rev() {
444        let line = lines[i].trim();
445        if line.len() >= 3 && line.chars().all(|c| c == '`') {
446            closing_line_idx = Some(i);
447            backtick_count = line.len();
448            break;
449        }
450    }
451
452    let closing_idx = closing_line_idx?;
453
454    // Search backwards for matching opening fence
455    // Opening fence starts with same backtick count, possibly followed by language/metadata
456    let opening_pattern = "`".repeat(backtick_count);
457
458    for i in (0..closing_idx).rev() {
459        let line = lines[i];
460        if line.starts_with(&opening_pattern) {
461            // Ensure it's exactly the right number of backticks (not more)
462            let rest = &line[backtick_count..];
463            if rest.is_empty() || !rest.starts_with('`') {
464                // Found matching opening fence
465                // Extract content between opening and closing (exclusive)
466                if closing_idx > i + 1 {
467                    let content = lines[i + 1..closing_idx].join("\n");
468                    // Preserve trailing newline to match previous behavior
469                    return Some(format!("{}\n", content));
470                } else {
471                    // Empty block
472                    return Some(String::new());
473                }
474            }
475        }
476    }
477
478    None
479}
480
481#[cfg(test)]
482mod tests {
483    use super::*;
484
485    #[test]
486    fn test_extract_last_code_block() {
487        let text = indoc::indoc! {"
488            Some thinking
489
490            ```
491            first block
492            ```
493
494            `````path='something' lines=1:2
495            last block
496            `````
497            "};
498        let last_block = extract_last_codeblock(text).unwrap();
499        assert_eq!(last_block, "last block\n");
500    }
501
502    #[test]
503    fn test_extract_codeblock_with_nested_fences() {
504        let text = indoc::indoc! {"
505            `````
506            content with ``` inline
507            and ```python nested
508            more content
509            `````
510            "};
511        let last_block = extract_last_codeblock(text).unwrap();
512        assert_eq!(
513            last_block,
514            "content with ``` inline\nand ```python nested\nmore content\n"
515        );
516    }
517
518    #[test]
519    fn test_extract_codeblock_ignores_inline_backticks() {
520        let text = indoc::indoc! {"
521            `````
522            here is some `code` with inline backticks
523            and here```more```stuff
524            `````
525            "};
526        let last_block = extract_last_codeblock(text).unwrap();
527        assert_eq!(
528            last_block,
529            "here is some `code` with inline backticks\nand here```more```stuff\n"
530        );
531    }
532
533    #[test]
534    fn test_extract_editable_region() {
535        let text = indoc::indoc! {"
536            some lines
537            are
538            here
539            <|editable_region_start|>
540            one
541            two three
542
543            <|editable_region_end|>
544            more
545            lines here
546            "};
547        let parsed = TeacherPrompt::extract_editable_region(text).unwrap();
548        assert_eq!(
549            parsed,
550            indoc::indoc! {"
551            one
552            two three"}
553        );
554    }
555
556    #[test]
557    fn test_extract_last_codeblock_nested_bibtex() {
558        let text = indoc::indoc! {r#"
559            Looking at the edit history, I can see that a Citation section was just added.
560
561            `````
562            ## Collaborations
563            Our mission is to create a 4D generative model.
564
565            ## Citation
566
567            If you found Unique3D helpful, please cite our report:
568            ```bibtex
569            @misc{wu2024unique3d,
570                  title={Unique3D},
571            }
572            ```
573            `````
574            "#};
575        let last_block = extract_last_codeblock(text).unwrap();
576        assert_eq!(
577            last_block,
578            indoc::indoc! {r#"
579            ## Collaborations
580            Our mission is to create a 4D generative model.
581
582            ## Citation
583
584            If you found Unique3D helpful, please cite our report:
585            ```bibtex
586            @misc{wu2024unique3d,
587                  title={Unique3D},
588            }
589            ```
590            "#}
591        );
592    }
593
594    #[test]
595    fn test_extract_editable_region_no_markers() {
596        let text = indoc::indoc! {"
597            one
598            two three"};
599        let parsed = TeacherPrompt::extract_editable_region(text).unwrap();
600        assert_eq!(
601            parsed,
602            indoc::indoc! {"
603            one
604            two three"}
605        );
606    }
607
608    #[test]
609    fn test_parse_no_edits_response() {
610        let response = indoc::indoc! {"
611            The code is already complete. There is no clear next edit to make.
612
613            `````
614            NO_EDITS
615            `````
616        "};
617        let codeblock = extract_last_codeblock(response).unwrap();
618        assert_eq!(codeblock.trim(), TeacherPrompt::NO_EDITS);
619    }
620
621    #[test]
622    fn test_extract_codeblock_no_valid_block() {
623        // Text with no code blocks should return None
624        let text = "Just some plain text without any code blocks";
625        assert!(extract_last_codeblock(text).is_none());
626
627        // Unclosed code block should return None
628        let text = indoc::indoc! {"
629            ```
630            unclosed block
631        "};
632        assert!(extract_last_codeblock(text).is_none());
633
634        // Analysis text with nested markdown but no proper outer block
635        let text = indoc::indoc! {"
636            # Analysis
637            Looking at this:
638            ```
639            some code
640            ```
641            But then more analysis without wrapping block
642        "};
643        // This should find the inner block
644        let result = extract_last_codeblock(text).unwrap();
645        assert_eq!(result, "some code\n");
646    }
647
648    #[test]
649    fn test_extract_codeblock_no_trailing_newline() {
650        // Text ending without trailing newline after closing fence
651        let text = "`````\ncontent here\n`````";
652        let result = extract_last_codeblock(text).unwrap();
653        assert_eq!(result, "content here\n");
654    }
655}