Improve commit line break unwrapping for variable-length list markers

src/common/gitUtils.ts

@@ -7,6 +7,350 @@ import * as vscode from 'vscode';
 import { Repository } from '../api/api';
 import { GitApiImpl } from '../api/api1';
 
+/**
+ * Unwraps lines that were wrapped for conventional commit message formatting (typically at 72 characters).
+ * Similar to GitHub's behavior when converting commit messages to PR descriptions.
+ *
+ * Rules:
+ * - Preserves blank lines as paragraph breaks
+ * - Preserves fenced code blocks (```)
+ * - Preserves list items (-, *, +, numbered)
+ * - Preserves blockquotes (>)
+ * - Preserves indented code blocks (4+ spaces at start, when not in a list context)
+ * - Joins consecutive plain text lines that appear to be wrapped mid-sentence
+ */
+export function unwrapCommitMessageBody(body: string): string {
+	if (!body) {
+		return body;
+	}
+
+	// Pattern to detect list item markers at the start of a line and capture the marker
+	const LIST_ITEM_PATTERN = /^(?<leadingWhitespace>[ \t]*)(?<marker>[*+\-]|\d+\.)(?<markerTrailingWhitespace>[ \t]+)/;
+	// Pattern to detect blockquote markers
+	const BLOCKQUOTE_PATTERN = /^[ \t]*>/;
+	// Pattern to detect fenced code block markers
+	const FENCE_PATTERN = /^[ \t]*```/;
+
+	const getLeadingWhitespaceLength = (text: string): number => text.match(/^[ \t]*/)?.[0].length ?? 0;
+	const hasHardLineBreak = (text: string): boolean => / {2}$/.test(text);
+	const appendWithSpace = (base: string, addition: string): string => {
+		if (!addition) {
+			return base;
+		}
+		return base.length > 0 && !/\s$/.test(base) ? `${base} ${addition}` : `${base}${addition}`;
+	};
+
+	// Get the content indent for a list item (position where actual content starts)
+	const getListItemContentIndent = (line: string): number => {
+		const match = line.match(LIST_ITEM_PATTERN);
+		if (!match?.groups) {
+			return 0;
+		}
+		// Content indent = leading whitespace + marker + space after marker
+		return match.groups.leadingWhitespace.length + match.groups.marker.length + match.groups.markerTrailingWhitespace.length;
+	};
+
+	const lines = body.split('\n');
+	const result: string[] = [];
+	let i = 0;
+	let inFencedBlock = false;
+	// Stack stores { markerIndent, contentIndent } for each nesting level
+	const listStack: { markerIndent: number; contentIndent: number }[] = [];
+
+	// Find the active list context for a given line indent
+	// Returns the content indent if the line is within an active list context
+	const getActiveListContentIndent = (lineIndent: number): number | undefined => {
+		for (let idx = listStack.length - 1; idx >= 0; idx--) {
+			const { markerIndent, contentIndent } = listStack[idx];
+			// A line is part of a list item if it has at least 1 space indent
+			// (but less than contentIndent + 4 which would be a code block)
+			if (lineIndent >= 1 && lineIndent >= markerIndent) {
+				listStack.length = idx + 1;
+				return contentIndent;
+			}
+			listStack.pop();
+		}
+		return undefined;
+	};
+
+	const shouldJoinListContinuation = (lineIndex: number, contentIndent: number, baseLine: string): boolean => {
+		const currentLine = lines[lineIndex];
+		if (!currentLine) {
+			return false;
+		}
+
+		const trimmed = currentLine.trim();
+		if (!trimmed) {
+			return false;
+		}
+
+		if (hasHardLineBreak(baseLine) || hasHardLineBreak(currentLine)) {
+			return false;
+		}
+
+		if (LIST_ITEM_PATTERN.test(currentLine)) {
+			return false;
+		}
+
+		if (BLOCKQUOTE_PATTERN.test(currentLine) || FENCE_PATTERN.test(currentLine)) {
+			return false;
+		}
+
+		const currentIndent = getLeadingWhitespaceLength(currentLine);
+		// Need at least 1 space to be a continuation
+		if (currentIndent < 1) {
+			return false;
+		}
+
+		// 4+ spaces beyond content indent is an indented code block
+		if (currentIndent >= contentIndent + 4) {
+			return false;
+		}
+
+		return true;
+	};
+
+	while (i < lines.length) {
+		const line = lines[i];
+
+		// Preserve blank lines but don't clear list context
+		// (multi-paragraph lists are allowed in GitHub markdown)
+		if (line.trim() === '') {
+			result.push(line);
+			i++;
+			continue;
+		}
+
+		// Check for fenced code block markers
+		if (FENCE_PATTERN.test(line)) {
+			inFencedBlock = !inFencedBlock;
+			result.push(line);
+			i++;
+			continue;
+		}
+
+		// Preserve everything inside fenced code blocks
+		if (inFencedBlock) {
+			result.push(line);
+			i++;
+			continue;
+		}
+
+		const lineIndent = getLeadingWhitespaceLength(line);
+		const listItemMatch = line.match(LIST_ITEM_PATTERN);
+
+		if (listItemMatch?.groups) {
+			const markerIndent = listItemMatch.groups.leadingWhitespace.length;
+			const contentIndent = getListItemContentIndent(line);
+
+			// Pop list levels that are at or beyond this indent
+			while (listStack.length && markerIndent <= listStack[listStack.length - 1].markerIndent) {
+				listStack.pop();
+			}
+
+			listStack.push({ markerIndent, contentIndent });
+			result.push(line);
+			i++;
+			continue;
+		}
+
+		// Handle non-indented lines that should be joined to a previous list item
+		// This happens when commit messages are wrapped at 72 characters
+		// Check this BEFORE calling getActiveListContentIndent which would clear the stack
+		if (listStack.length > 0 && lineIndent === 0 && !LIST_ITEM_PATTERN.test(line)) {
+			const isBlockquote = BLOCKQUOTE_PATTERN.test(line);
+			if (!isBlockquote) {
+				const baseIndex = result.length - 1;
+				const baseLine = baseIndex >= 0 ? result[baseIndex] : '';
+				const previousLineIsBlank = baseLine.trim() === '';
+
+				if (!previousLineIsBlank && baseIndex >= 0) {
+					// Join this line and any following non-list-item lines with the previous list item
+					let joinedLine = baseLine;
+					let currentIndex = i;
+
+					while (currentIndex < lines.length) {
+						const currentLine = lines[currentIndex];
+						const trimmed = currentLine.trim();
+
+						// Stop at blank lines
+						if (!trimmed) {
+							break;
+						}
+
+						// Stop at list items
+						if (LIST_ITEM_PATTERN.test(currentLine)) {
+							break;
+						}
+
+						// Stop at blockquotes or fences
+						if (BLOCKQUOTE_PATTERN.test(currentLine) || FENCE_PATTERN.test(currentLine)) {
+							break;
+						}
+
+						// Stop at indented code blocks
+						const currentLineIndent = getLeadingWhitespaceLength(currentLine);
+						if (currentLineIndent >= 4) {
+							break;
+						}
+
+						// Stop if previous line has hard line break
+						if (hasHardLineBreak(joinedLine)) {
+							break;
+						}
+
+						joinedLine = appendWithSpace(joinedLine, trimmed);
+						currentIndex++;
+					}
+
+					if (currentIndex > i) {
+						result[baseIndex] = joinedLine;
+						i = currentIndex;
+						continue;
+					}
+				}
+			}
+		}
+
+		const activeContentIndent = getActiveListContentIndent(lineIndent);
+		const codeIndentThreshold = activeContentIndent !== undefined ? activeContentIndent + 4 : 4;
+		const isBlockquote = BLOCKQUOTE_PATTERN.test(line);
+		const isIndentedCode = lineIndent >= codeIndentThreshold;
+
+		if (isBlockquote || isIndentedCode) {
+			result.push(line);
+			i++;
+			continue;
+		}
+
+		// Handle list item continuations
+		if (activeContentIndent !== undefined && lineIndent >= 1) {
+			const baseIndex = result.length - 1;
+			// Only try to join with previous line if it's not blank
+			// Multi-paragraph lists have blank lines that should be preserved
+			const baseLine = baseIndex >= 0 ? result[baseIndex] : '';
+			const previousLineIsBlank = baseLine.trim() === '';
+
+			if (!previousLineIsBlank && baseIndex >= 0) {
+				let joinedLine = baseLine;
+				let appended = false;
+				let currentIndex = i;
+
+				while (
+					currentIndex < lines.length &&
+					shouldJoinListContinuation(currentIndex, activeContentIndent, joinedLine)
+				) {
+					const continuationText = lines[currentIndex].trim();
+					if (continuationText) {
+						joinedLine = appendWithSpace(joinedLine, continuationText);
+						appended = true;
+					}
+					currentIndex++;
+				}
+
+				if (appended) {
+					result[baseIndex] = joinedLine;
+					i = currentIndex;
+					continue;
+				}
+			}
+
+			// For multi-paragraph continuations or standalone indented lines,
+			// preserve indentation but unwrap consecutive continuation lines
+			let joinedLine = line;
+			i++;
+
+			while (i < lines.length) {
+				const nextLine = lines[i];
+
+				if (nextLine.trim() === '') {
+					break;
+				}
+
+				if (FENCE_PATTERN.test(nextLine)) {
+					break;
+				}
+
+				if (LIST_ITEM_PATTERN.test(nextLine)) {
+					break;
+				}
+
+				if (BLOCKQUOTE_PATTERN.test(nextLine)) {
+					break;
+				}
+
+				const nextIndent = getLeadingWhitespaceLength(nextLine);
+				// Check for code block
+				if (nextIndent >= activeContentIndent + 4) {
+					break;
+				}
+
+				// Must have at least 1 space to be a continuation
+				if (nextIndent < 1) {
+					break;
+				}
+
+				// Check for hard line break
+				if (hasHardLineBreak(joinedLine)) {
+					break;
+				}
+
+				// Join this line - preserve the original indentation for the first line
+				joinedLine = appendWithSpace(joinedLine, nextLine.trim());
+				i++;
+			}
+
+			result.push(joinedLine);
+			continue;
+		}
+
+		// Start accumulating lines that should be joined (plain text)
+		let joinedLine = line;
+		i++;
+
+		// Keep joining lines until we hit a blank line or a line that shouldn't be joined
+		while (i < lines.length) {
+			const nextLine = lines[i];
+
+			// Stop at blank lines
+			if (nextLine.trim() === '') {
+				break;
+			}
+
+			// Stop at fenced code blocks
+			if (FENCE_PATTERN.test(nextLine)) {
+				break;
+			}
+
+			// Stop at list items
+			if (LIST_ITEM_PATTERN.test(nextLine)) {
+				break;
+			}
+
+			// Stop at blockquotes
+			if (BLOCKQUOTE_PATTERN.test(nextLine)) {
+				break;
+			}
+
+			// Check if next line is indented code (4+ spaces, when not in a list context)
+			const nextLeadingSpaces = getLeadingWhitespaceLength(nextLine);
+			const nextIsIndentedCode = nextLeadingSpaces >= 4;
+
+			if (nextIsIndentedCode) {
+				break;
+			}
+
+			// Join this line with a space
+			joinedLine = appendWithSpace(joinedLine, nextLine.trim());
+			i++;
+		}
+
+		result.push(joinedLine);
+	}
+
+	return result.join('\n');
+}
+
 /**
  * Determines if a repository is a submodule by checking if its path
  * appears in any other repository's submodules list.