/**
* Unit tests for truncation utility
*/
import { describe, test, expect } from '@jest/globals';
import {
truncateOutput,
buildTruncationMessage,
formatTruncatedOutput
} from '../../src/utils/truncation.js';
import { TruncationConfig } from '../../src/types/logging.js';
describe('truncateOutput', () => {
const defaultConfig: TruncationConfig = {
maxOutputLines: 20,
enableTruncation: true,
truncationMessage: '[Output truncated: Showing last {returnedLines} of {totalLines} lines]'
};
describe('basic functionality', () => {
test('should not truncate output shorter than limit', () => {
const output = 'line1\nline2\nline3';
const result = truncateOutput(output, 10, defaultConfig);
expect(result.wasTruncated).toBe(false);
expect(result.output).toBe(output);
expect(result.totalLines).toBe(3);
expect(result.returnedLines).toBe(3);
expect(result.message).toBeNull();
});
test('should truncate output longer than limit', () => {
const lines = Array.from({ length: 100 }, (_, i) => `line ${i + 1}`);
const output = lines.join('\n');
const result = truncateOutput(output, 20, defaultConfig);
expect(result.wasTruncated).toBe(true);
expect(result.totalLines).toBe(100);
expect(result.returnedLines).toBe(20);
expect(result.output).toContain('line 81'); // First of last 20
expect(result.output).toContain('line 100'); // Last line
expect(result.output.startsWith('line 81')).toBe(true); // Should start with line 81
expect(result.output).not.toMatch(/^line 1\n/); // First line not included
});
test('should include truncation message', () => {
const lines = Array.from({ length: 100 }, (_, i) => `line ${i + 1}`);
const output = lines.join('\n');
const result = truncateOutput(output, 20, defaultConfig, 'exec-id-123');
expect(result.message).toBeDefined();
expect(result.message).toContain('Showing last 20 of 100 lines');
expect(result.message).toContain('80 lines omitted');
expect(result.message).toContain('exec-id-123');
});
test('should return last N lines', () => {
const lines = Array.from({ length: 50 }, (_, i) => `line ${i + 1}`);
const output = lines.join('\n');
const result = truncateOutput(output, 10, defaultConfig);
const resultLines = result.output.split('\n');
expect(resultLines.length).toBe(10);
expect(resultLines[0]).toBe('line 41');
expect(resultLines[9]).toBe('line 50');
});
});
describe('edge cases', () => {
test('should handle empty output', () => {
const result = truncateOutput('', 20, defaultConfig);
expect(result.wasTruncated).toBe(false);
expect(result.output).toBe('');
expect(result.totalLines).toBe(0);
expect(result.returnedLines).toBe(0);
});
test('should handle single line', () => {
const result = truncateOutput('single line', 20, defaultConfig);
expect(result.wasTruncated).toBe(false);
expect(result.totalLines).toBe(1);
expect(result.returnedLines).toBe(1);
});
test('should handle exactly at limit', () => {
const lines = Array.from({ length: 20 }, (_, i) => `line ${i + 1}`);
const output = lines.join('\n');
const result = truncateOutput(output, 20, defaultConfig);
expect(result.wasTruncated).toBe(false);
expect(result.totalLines).toBe(20);
expect(result.returnedLines).toBe(20);
});
test('should handle one line over limit', () => {
const lines = Array.from({ length: 21 }, (_, i) => `line ${i + 1}`);
const output = lines.join('\n');
const result = truncateOutput(output, 20, defaultConfig);
expect(result.wasTruncated).toBe(true);
expect(result.totalLines).toBe(21);
expect(result.returnedLines).toBe(20);
expect(result.output).toContain('line 2');
expect(result.output).toContain('line 21');
expect(result.output.startsWith('line 2')).toBe(true); // Should start with line 2
expect(result.output).not.toMatch(/^line 1\n/); // First line not included
});
test('should handle very long single line', () => {
const output = 'a'.repeat(10000);
const result = truncateOutput(output, 20, defaultConfig);
expect(result.wasTruncated).toBe(false);
expect(result.totalLines).toBe(1);
});
test('should handle output with empty lines', () => {
const output = 'line1\n\nline3\n\nline5';
const result = truncateOutput(output, 3, defaultConfig);
expect(result.wasTruncated).toBe(true);
expect(result.totalLines).toBe(5);
expect(result.returnedLines).toBe(3);
});
});
describe('configuration', () => {
test('should respect truncation disabled', () => {
const config: TruncationConfig = {
...defaultConfig,
enableTruncation: false
};
const lines = Array.from({ length: 100 }, (_, i) => `line ${i + 1}`);
const output = lines.join('\n');
const result = truncateOutput(output, 20, config);
expect(result.wasTruncated).toBe(false);
expect(result.totalLines).toBe(100);
expect(result.returnedLines).toBe(100);
expect(result.output).toBe(output);
});
test('should respect custom message template', () => {
const customConfig: TruncationConfig = {
...defaultConfig,
truncationMessage: 'Custom: {returnedLines}/{totalLines}'
};
const lines = Array.from({ length: 100 }, (_, i) => `line ${i + 1}`);
const output = lines.join('\n');
const result = truncateOutput(output, 20, customConfig);
expect(result.message).toContain('Custom: 20/100');
});
test('should handle no execution ID', () => {
const lines = Array.from({ length: 100 }, (_, i) => `line ${i + 1}`);
const output = lines.join('\n');
const result = truncateOutput(output, 20, defaultConfig, undefined);
expect(result.message).toBeDefined();
expect(result.message).not.toContain('cli://logs/commands/');
});
test('should handle different maxLines values', () => {
const lines = Array.from({ length: 100 }, (_, i) => `line ${i + 1}`);
const output = lines.join('\n');
const result5 = truncateOutput(output, 5, defaultConfig);
expect(result5.returnedLines).toBe(5);
const result50 = truncateOutput(output, 50, defaultConfig);
expect(result50.returnedLines).toBe(50);
const result100 = truncateOutput(output, 100, defaultConfig);
expect(result100.wasTruncated).toBe(false);
});
});
});
describe('buildTruncationMessage', () => {
const template = '[Output truncated: Showing last {returnedLines} of {totalLines} lines]';
test('should replace all placeholders', () => {
const message = buildTruncationMessage(80, 100, 20, 'exec-123', template);
expect(message).toContain('Showing last 20 of 100 lines');
expect(message).toContain('80 lines omitted');
});
test('should include execution ID when provided', () => {
const message = buildTruncationMessage(80, 100, 20, 'exec-123', template);
expect(message).toContain('cli://logs/commands/exec-123');
});
test('should not include URI when no execution ID', () => {
const message = buildTruncationMessage(80, 100, 20, undefined, template);
expect(message).not.toContain('cli://logs/commands/');
});
test('should handle default template', () => {
const message = buildTruncationMessage(50, 100, 50, undefined, undefined);
expect(message).toBeDefined();
expect(message.length).toBeGreaterThan(0);
});
test('should handle various line counts', () => {
const message1 = buildTruncationMessage(1, 21, 20, undefined, template);
expect(message1).toContain('1 lines omitted');
const message99 = buildTruncationMessage(99, 100, 1, undefined, template);
expect(message99).toContain('99 lines omitted');
});
test('should include basename when exposeFullPath is false', () => {
const message = buildTruncationMessage(
10,
20,
10,
'exec-abc',
template,
'C:\\logs\\full\\run.log',
false,
true
);
expect(message).toContain('run.log');
expect(message).not.toContain('C:\\logs\\full\\run.log');
// When file path is provided, we don't show the fallback (file is simpler to access)
expect(message).not.toContain('get_command_output');
expect(message).not.toContain('cli://logs/commands');
});
test('should include full path when exposeFullPath is true', () => {
const message = buildTruncationMessage(
10,
20,
10,
'exec-abc',
template,
'C:\\logs\\full\\run.log',
true,
true
);
expect(message).toContain('C:\\logs\\full\\run.log');
});
test('should omit resource link when log resources disabled', () => {
const message = buildTruncationMessage(
10,
20,
10,
'exec-abc',
template,
'C:\\logs\\full\\run.log',
false,
false
);
// When file path is provided, only file path is shown (no MCP resource or tool)
expect(message).not.toContain('cli://logs/commands/exec-abc');
expect(message).not.toContain('get_command_output');
expect(message).toContain('run.log');
});
test('should show MCP resource and tool when no file path (in-memory)', () => {
const message = buildTruncationMessage(
10,
20,
10,
'exec-abc',
template,
undefined, // No file path
false,
true
);
expect(message).toContain('cli://logs/commands/exec-abc');
expect(message).toContain('get_command_output');
});
test('should show nothing extra when no file path and log resources disabled', () => {
const message = buildTruncationMessage(
10,
20,
10,
'exec-abc',
template,
undefined, // No file path
false,
false // Log resources disabled
);
expect(message).not.toContain('cli://logs/commands');
expect(message).not.toContain('get_command_output');
expect(message).not.toContain('Full log saved');
});
});
describe('formatTruncatedOutput', () => {
test('should return output without message when not truncated', () => {
const truncated = {
output: 'test output',
wasTruncated: false,
totalLines: 1,
returnedLines: 1,
message: null
};
const result = formatTruncatedOutput(truncated);
expect(result).toBe('test output');
});
test('should combine message and output when truncated', () => {
const truncated = {
output: 'last line',
wasTruncated: true,
totalLines: 100,
returnedLines: 1,
message: '[Truncation message]'
};
const result = formatTruncatedOutput(truncated);
expect(result).toContain('[Truncation message]');
expect(result).toContain('last line');
expect(result.indexOf('[Truncation message]')).toBeLessThan(result.indexOf('last line'));
});
test('should handle truncated but no message', () => {
const truncated = {
output: 'output',
wasTruncated: true,
totalLines: 100,
returnedLines: 1,
message: null
};
const result = formatTruncatedOutput(truncated);
expect(result).toBe('output');
});
test('should preserve formatting in output', () => {
const truncated = {
output: 'line1\nline2\nline3',
wasTruncated: true,
totalLines: 100,
returnedLines: 3,
message: 'Message'
};
const result = formatTruncatedOutput(truncated);
expect(result).toContain('line1\nline2\nline3');
});
});
