File size: 4,612 Bytes
f500658 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 | import * as Diff from "diff";
import { theme } from "../theme/theme.ts";
/**
* Parse diff line to extract prefix, line number, and content.
* Format: "+123 content" or "-123 content" or " 123 content" or " ..."
*/
function parseDiffLine(line: string): { prefix: string; lineNum: string; content: string } | null {
const match = line.match(/^([+-\s])(\s*\d*)\s(.*)$/);
if (!match) return null;
return { prefix: match[1], lineNum: match[2], content: match[3] };
}
/**
* Replace tabs with spaces for consistent rendering.
*/
function replaceTabs(text: string): string {
return text.replace(/\t/g, " ");
}
/**
* Compute word-level diff and render with inverse on changed parts.
* Uses diffWords which groups whitespace with adjacent words for cleaner highlighting.
* Strips leading whitespace from inverse to avoid highlighting indentation.
*/
function renderIntraLineDiff(oldContent: string, newContent: string): { removedLine: string; addedLine: string } {
const wordDiff = Diff.diffWords(oldContent, newContent);
let removedLine = "";
let addedLine = "";
let isFirstRemoved = true;
let isFirstAdded = true;
for (const part of wordDiff) {
if (part.removed) {
let value = part.value;
// Strip leading whitespace from the first removed part
if (isFirstRemoved) {
const leadingWs = value.match(/^(\s*)/)?.[1] || "";
value = value.slice(leadingWs.length);
removedLine += leadingWs;
isFirstRemoved = false;
}
if (value) {
removedLine += theme.inverse(value);
}
} else if (part.added) {
let value = part.value;
// Strip leading whitespace from the first added part
if (isFirstAdded) {
const leadingWs = value.match(/^(\s*)/)?.[1] || "";
value = value.slice(leadingWs.length);
addedLine += leadingWs;
isFirstAdded = false;
}
if (value) {
addedLine += theme.inverse(value);
}
} else {
removedLine += part.value;
addedLine += part.value;
}
}
return { removedLine, addedLine };
}
export interface RenderDiffOptions {
/** File path (unused, kept for API compatibility) */
filePath?: string;
}
/**
* Render a diff string with colored lines and intra-line change highlighting.
* - Context lines: dim/gray
* - Removed lines: red, with inverse on changed tokens
* - Added lines: green, with inverse on changed tokens
*/
export function renderDiff(diffText: string, _options: RenderDiffOptions = {}): string {
const lines = diffText.split("\n");
const result: string[] = [];
let i = 0;
while (i < lines.length) {
const line = lines[i];
const parsed = parseDiffLine(line);
if (!parsed) {
result.push(theme.fg("toolDiffContext", line));
i++;
continue;
}
if (parsed.prefix === "-") {
// Collect consecutive removed lines
const removedLines: { lineNum: string; content: string }[] = [];
while (i < lines.length) {
const p = parseDiffLine(lines[i]);
if (!p || p.prefix !== "-") break;
removedLines.push({ lineNum: p.lineNum, content: p.content });
i++;
}
// Collect consecutive added lines
const addedLines: { lineNum: string; content: string }[] = [];
while (i < lines.length) {
const p = parseDiffLine(lines[i]);
if (!p || p.prefix !== "+") break;
addedLines.push({ lineNum: p.lineNum, content: p.content });
i++;
}
// Only do intra-line diffing when there's exactly one removed and one added line
// (indicating a single line modification). Otherwise, show lines as-is.
if (removedLines.length === 1 && addedLines.length === 1) {
const removed = removedLines[0];
const added = addedLines[0];
const { removedLine, addedLine } = renderIntraLineDiff(
replaceTabs(removed.content),
replaceTabs(added.content),
);
result.push(theme.fg("toolDiffRemoved", `-${removed.lineNum} ${removedLine}`));
result.push(theme.fg("toolDiffAdded", `+${added.lineNum} ${addedLine}`));
} else {
// Show all removed lines first, then all added lines
for (const removed of removedLines) {
result.push(theme.fg("toolDiffRemoved", `-${removed.lineNum} ${replaceTabs(removed.content)}`));
}
for (const added of addedLines) {
result.push(theme.fg("toolDiffAdded", `+${added.lineNum} ${replaceTabs(added.content)}`));
}
}
} else if (parsed.prefix === "+") {
// Standalone added line
result.push(theme.fg("toolDiffAdded", `+${parsed.lineNum} ${replaceTabs(parsed.content)}`));
i++;
} else {
// Context line
result.push(theme.fg("toolDiffContext", ` ${parsed.lineNum} ${replaceTabs(parsed.content)}`));
i++;
}
}
return result.join("\n");
}
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