/**
* Git Diff Tool
* Show differences between commits, branches, or working directory
*/
import { Tool } from '@modelcontextprotocol/sdk/types.js';
import { exec } from 'child_process';
import { promisify } from 'util';
import { ServerConfig } from '../config.js';
import { WorkspaceError, ErrorCode } from '../utils/errors.js';
const execAsync = promisify(exec);
export interface GitDiffArgs {
target?: string;
source?: string;
staged?: boolean;
nameOnly?: boolean;
statOnly?: boolean;
contextLines?: number;
files?: string[];
}
export interface GitDiffResult {
diff: string;
files: GitDiffFile[];
summary: {
filesChanged: number;
insertions: number;
deletions: number;
};
}
export interface GitDiffFile {
file: string;
status: string;
insertions: number;
deletions: number;
}
export const gitDiffTool: Tool = {
name: 'git_diff',
description: 'Show differences between commits, branches, or working directory',
inputSchema: {
type: 'object',
properties: {
target: {
type: 'string',
description: 'Target commit, branch, or tag to compare against (default: HEAD)'
},
source: {
type: 'string',
description: 'Source commit, branch, or tag to compare from'
},
staged: {
type: 'boolean',
description: 'Show staged changes only',
default: false
},
nameOnly: {
type: 'boolean',
description: 'Show only file names',
default: false
},
statOnly: {
type: 'boolean',
description: 'Show only statistics',
default: false
},
contextLines: {
type: 'number',
description: 'Number of context lines to show',
default: 3
},
files: {
type: 'array',
items: { type: 'string' },
description: 'Specific files to show diff for'
}
}
}
};
export async function executeGitDiff(
args: GitDiffArgs,
config: ServerConfig
): Promise<GitDiffResult> {
const {
target,
source,
staged = false,
nameOnly = false,
statOnly = false,
contextLines = 3,
files = []
} = args;
// Check if git is allowed
if (!config.allowedCommands.includes('git')) {
throw new WorkspaceError(
ErrorCode.COMMAND_NOT_ALLOWED,
'Git commands are not allowed. Add "git" to allowedCommands in configuration.'
);
}
try {
// Build git diff command
let command = 'git diff';
if (staged) {
command += ' --staged';
}
if (nameOnly) {
command += ' --name-only';
} else if (statOnly) {
command += ' --stat';
} else {
command += ` --unified=${contextLines}`;
}
// Add source and target
if (source && target) {
command += ` ${source}..${target}`;
} else if (target) {
command += ` ${target}`;
}
// Add specific files
if (files.length > 0) {
command += ' -- ' + files.join(' ');
}
// Execute diff command
const diffResult = await execAsync(command, {
cwd: config.workspaceRoot,
timeout: 30000
});
let diff = diffResult.stdout;
// Get file statistics
const statCommand = command.replace(/--unified=\d+/, '--stat').replace('--name-only', '--stat');
let statResult: { stdout: string } = { stdout: '' };
try {
statResult = await execAsync(statCommand, {
cwd: config.workspaceRoot,
timeout: 15000
});
} catch {
// Stats might not be available
}
const diffFiles: GitDiffFile[] = [];
let filesChanged = 0;
let totalInsertions = 0;
let totalDeletions = 0;
// Parse statistics
if (statResult.stdout) {
const statLines = statResult.stdout.trim().split('\n');
for (const line of statLines) {
if (line.includes('|')) {
const match = line.match(/^(.+?)\s+\|\s+(\d+)\s+([+-]+)$/);
if (match) {
const [, file, , symbols] = match;
const insertions = (symbols.match(/\+/g) || []).length;
const deletions = (symbols.match(/-/g) || []).length;
diffFiles.push({
file: file.trim(),
status: 'M', // Modified (could be more specific)
insertions,
deletions
});
totalInsertions += insertions;
totalDeletions += deletions;
}
} else if (line.includes('file') && line.includes('changed')) {
const match = line.match(/(\d+) files? changed/);
if (match) {
filesChanged = parseInt(match[1], 10);
}
const insertMatch = line.match(/(\d+) insertions?/);
if (insertMatch) {
totalInsertions = parseInt(insertMatch[1], 10);
}
const deleteMatch = line.match(/(\d+) deletions?/);
if (deleteMatch) {
totalDeletions = parseInt(deleteMatch[1], 10);
}
}
}
}
// If no files were parsed from stats, try to get them from name-only
if (diffFiles.length === 0 && !nameOnly) {
try {
const nameOnlyCommand = command.replace(/--unified=\d+/, '--name-only').replace('--stat', '--name-only');
const nameResult = await execAsync(nameOnlyCommand, {
cwd: config.workspaceRoot,
timeout: 15000
});
const fileNames = nameResult.stdout.trim().split('\n').filter(name => name.length > 0);
for (const fileName of fileNames) {
diffFiles.push({
file: fileName,
status: 'M',
insertions: 0,
deletions: 0
});
}
} catch {
// Ignore errors
}
}
return {
diff,
files: diffFiles,
summary: {
filesChanged: filesChanged || diffFiles.length,
insertions: totalInsertions,
deletions: totalDeletions
}
};
} catch (error) {
if (error instanceof WorkspaceError) {
throw error;
}
throw new WorkspaceError(
ErrorCode.FILESYSTEM_ERROR,
`Failed to get git diff: ${error instanceof Error ? error.message : 'Unknown error'}`
);
}
}
