test: add comprehensive tests for read_file maxReadFileLine settings

- Tests behavior when maxReadFileLine is -1 (reads entire file)
- Tests behavior when maxReadFileLine >= file length (reads entire file)
- Tests behavior when maxReadFileLine is 0 (shows only definitions)
- Tests behavior when maxReadFileLine < file length (truncates content)
- Verifies exact line counts in responses
- Adds helper functions for response validation
- Includes DEBUG flag for controlled logging

Author: Eric Wheeler

src/core/__tests__/read-file-maxReadFileLine.test.ts

@@ -0,0 +1,325 @@
+const DEBUG = false
+
+import * as path from "path"
+import { countFileLines } from "../../integrations/misc/line-counter"
+import { readLines } from "../../integrations/misc/read-lines"
+import { extractTextFromFile, addLineNumbers } from "../../integrations/misc/extract-text"
+import { parseSourceCodeDefinitionsForFile } from "../../services/tree-sitter"
+import { isBinaryFile } from "isbinaryfile"
+import { ReadFileToolUse } from "../assistant-message"
+import { Cline } from "../Cline"
+import { ClineProvider } from "../webview/ClineProvider"
+
+// Mock dependencies
+jest.mock("../../integrations/misc/line-counter")
+jest.mock("../../integrations/misc/read-lines")
+jest.mock("../../integrations/misc/extract-text")
+jest.mock("../../services/tree-sitter")
+jest.mock("isbinaryfile")
+jest.mock("../ignore/RooIgnoreController", () => ({
+	RooIgnoreController: class {
+		initialize() {
+			return Promise.resolve()
+		}
+		validateAccess(filePath: string) {
+			return true
+		}
+	},
+}))
+jest.mock("fs/promises", () => ({
+	mkdir: jest.fn().mockResolvedValue(undefined),
+	writeFile: jest.fn().mockResolvedValue(undefined),
+	readFile: jest.fn().mockResolvedValue("{}"),
+}))
+jest.mock("../../utils/fs", () => ({
+	fileExistsAtPath: jest.fn().mockReturnValue(true),
+}))
+
+// Mock path
+jest.mock("path", () => {
+	const originalPath = jest.requireActual("path")
+	return {
+		...originalPath,
+		resolve: jest.fn().mockImplementation((...args) => args.join("/")),
+	}
+})
+
+describe("read_file tool with maxReadFileLine setting", () => {
+	// Mock original implementation first to use in tests
+	const originalCountFileLines = jest.requireActual("../../integrations/misc/line-counter").countFileLines
+	const originalReadLines = jest.requireActual("../../integrations/misc/read-lines").readLines
+	const originalExtractTextFromFile = jest.requireActual("../../integrations/misc/extract-text").extractTextFromFile
+	const originalAddLineNumbers = jest.requireActual("../../integrations/misc/extract-text").addLineNumbers
+	const originalParseSourceCodeDefinitionsForFile =
+		jest.requireActual("../../services/tree-sitter").parseSourceCodeDefinitionsForFile
+	const originalIsBinaryFile = jest.requireActual("isbinaryfile").isBinaryFile
+
+	let cline: Cline
+	let mockProvider: any
+	const testFilePath = "test/file.txt"
+	const absoluteFilePath = "/home/ewheeler/src/roo/roo-main/test/file.txt"
+	const fileContent = "Line 1\nLine 2\nLine 3\nLine 4\nLine 5"
+	const numberedFileContent = "1 | Line 1\n2 | Line 2\n3 | Line 3\n4 | Line 4\n5 | Line 5"
+	const sourceCodeDef = "\n\n# file.txt\n1--5 | Content"
+
+	beforeEach(() => {
+		jest.resetAllMocks()
+
+		// Reset mocks to simulate original behavior
+		;(countFileLines as jest.Mock).mockImplementation(originalCountFileLines)
+		;(readLines as jest.Mock).mockImplementation(originalReadLines)
+		;(extractTextFromFile as jest.Mock).mockImplementation(originalExtractTextFromFile)
+		;(parseSourceCodeDefinitionsForFile as jest.Mock).mockImplementation(originalParseSourceCodeDefinitionsForFile)
+		;(isBinaryFile as jest.Mock).mockImplementation(originalIsBinaryFile)
+
+		// Default mock implementations
+		;(countFileLines as jest.Mock).mockResolvedValue(5)
+		;(readLines as jest.Mock).mockResolvedValue(fileContent)
+		;(extractTextFromFile as jest.Mock).mockResolvedValue(numberedFileContent)
+		// Use the real addLineNumbers function
+		;(addLineNumbers as jest.Mock).mockImplementation(originalAddLineNumbers)
+		;(parseSourceCodeDefinitionsForFile as jest.Mock).mockResolvedValue(sourceCodeDef)
+		;(isBinaryFile as jest.Mock).mockResolvedValue(false)
+
+		// Add spy to debug the readLines calls
+		const readLinesSpy = jest.spyOn(require("../../integrations/misc/read-lines"), "readLines")
+
+		// Mock path.resolve to return a predictable path
+		;(path.resolve as jest.Mock).mockReturnValue(absoluteFilePath)
+
+		// Create mock provider
+		mockProvider = {
+			getState: jest.fn(),
+			deref: jest.fn().mockReturnThis(),
+		}
+
+		// Create a Cline instance with the necessary configuration
+		cline = new Cline({
+			provider: mockProvider,
+			apiConfiguration: { apiProvider: "anthropic" } as any,
+			task: "Test read_file tool", // Required to satisfy constructor check
+			startTask: false, // Prevent actual task initialization
+		})
+
+		// Set up the read_file tool use
+		const readFileToolUse: ReadFileToolUse = {
+			type: "tool_use",
+			name: "read_file",
+			params: {
+				path: testFilePath,
+			},
+			partial: false,
+		}
+
+		// Set up the Cline instance for testing
+		const clineAny = cline as any
+
+		// Set up the required properties for the test
+		clineAny.assistantMessageContent = [readFileToolUse]
+		clineAny.currentStreamingContentIndex = 0
+		clineAny.userMessageContent = []
+		clineAny.presentAssistantMessageLocked = false
+		clineAny.didCompleteReadingStream = true
+		clineAny.didRejectTool = false
+		clineAny.didAlreadyUseTool = false
+
+		// Mock methods that would be called during presentAssistantMessage
+		clineAny.say = jest.fn().mockResolvedValue(undefined)
+		clineAny.ask = jest.fn().mockImplementation((type, message) => {
+			return Promise.resolve({ response: "yesButtonClicked" })
+		})
+	})
+
+	// Helper function to get user message content
+	const getUserMessageContent = (clineInstance: Cline) => {
+		const clineAny = clineInstance as any
+		return clineAny.userMessageContent
+	}
+
+	// Helper function to validate response lines
+	const validateResponseLines = (
+		responseLines: string[],
+		options: {
+			expectedLineCount: number
+			shouldContainLines?: number[]
+			shouldNotContainLines?: number[]
+		},
+	) => {
+		if (options.shouldContainLines) {
+			const contentLines = responseLines.filter((line) => line.includes("Line "))
+			expect(contentLines.length).toBe(options.expectedLineCount)
+			options.shouldContainLines.forEach((lineNum) => {
+				expect(contentLines[lineNum - 1]).toContain(`Line ${lineNum}`)
+			})
+		}
+
+		if (options.shouldNotContainLines) {
+			options.shouldNotContainLines.forEach((lineNum) => {
+				expect(responseLines.some((line) => line.includes(`Line ${lineNum}`))).toBe(false)
+			})
+		}
+	}
+
+	interface TestExpectations {
+		extractTextCalled: boolean
+		readLinesCalled: boolean
+		sourceCodeDefCalled: boolean
+		readLinesParams?: [string, number, number]
+		responseValidation: {
+			expectedLineCount: number
+			shouldContainLines?: number[]
+			shouldNotContainLines?: number[]
+		}
+		expectedContent?: string
+		truncationMessage?: string
+		includeSourceCodeDef?: boolean
+	}
+
+	interface TestCase {
+		name: string
+		maxReadFileLine: number
+		setup?: () => void
+		expectations: TestExpectations
+	}
+
+	// Test cases
+	const testCases: TestCase[] = [
+		{
+			name: "read entire file when maxReadFileLine is -1",
+			maxReadFileLine: -1,
+			expectations: {
+				extractTextCalled: true,
+				readLinesCalled: false,
+				sourceCodeDefCalled: false,
+				responseValidation: {
+					expectedLineCount: 5,
+					shouldContainLines: [1, 2, 3, 4, 5],
+				},
+				expectedContent: numberedFileContent,
+			},
+		},
+		{
+			name: "read entire file when maxReadFileLine >= file length",
+			maxReadFileLine: 10,
+			expectations: {
+				extractTextCalled: true,
+				readLinesCalled: false,
+				sourceCodeDefCalled: false,
+				responseValidation: {
+					expectedLineCount: 5,
+					shouldContainLines: [1, 2, 3, 4, 5],
+				},
+				expectedContent: numberedFileContent,
+			},
+		},
+		{
+			name: "read zero lines and only provide line declaration definitions when maxReadFileLine is 0",
+			maxReadFileLine: 0,
+			expectations: {
+				extractTextCalled: false,
+				readLinesCalled: false,
+				sourceCodeDefCalled: true,
+				responseValidation: {
+					expectedLineCount: 0,
+				},
+				truncationMessage: `[Showing only 0 of 5 total lines. Use start_line and end_line if you need to read more]`,
+				includeSourceCodeDef: true,
+			},
+		},
+		{
+			name: "read maxReadFileLine lines and provide line declaration definitions when maxReadFileLine < file length",
+			maxReadFileLine: 3,
+			setup: () => {
+				jest.clearAllMocks()
+				;(countFileLines as jest.Mock).mockResolvedValue(5)
+				;(readLines as jest.Mock).mockImplementation((path, endLine, startLine = 0) => {
+					const lines = fileContent.split("\n")
+					const actualEndLine = endLine !== undefined ? Math.min(endLine, lines.length - 1) : lines.length - 1
+					const actualStartLine = startLine !== undefined ? Math.min(startLine, lines.length - 1) : 0
+					const requestedLines = lines.slice(actualStartLine, actualEndLine + 1)
+					return Promise.resolve(requestedLines.join("\n"))
+				})
+			},
+			expectations: {
+				extractTextCalled: false,
+				readLinesCalled: true,
+				sourceCodeDefCalled: true,
+				readLinesParams: [absoluteFilePath, 2, 0],
+				responseValidation: {
+					expectedLineCount: 3,
+					shouldContainLines: [1, 2, 3],
+					shouldNotContainLines: [4, 5],
+				},
+				truncationMessage: `[Showing only 3 of 5 total lines. Use start_line and end_line if you need to read more]`,
+				includeSourceCodeDef: true,
+			},
+		},
+	]
+
+	test.each(testCases)("should $name", async (testCase) => {
+		// Setup
+		if (testCase.setup) {
+			testCase.setup()
+		}
+		mockProvider.getState.mockResolvedValue({ maxReadFileLine: testCase.maxReadFileLine })
+
+		// Execute
+		await cline.presentAssistantMessage()
+
+		// Verify mock calls
+		if (testCase.expectations.extractTextCalled) {
+			expect(extractTextFromFile).toHaveBeenCalledWith(absoluteFilePath)
+		} else {
+			expect(extractTextFromFile).not.toHaveBeenCalled()
+		}
+
+		if (testCase.expectations.readLinesCalled) {
+			const params = testCase.expectations.readLinesParams
+			if (!params) {
+				throw new Error("readLinesParams must be defined when readLinesCalled is true")
+			}
+			expect(readLines).toHaveBeenCalledWith(...params)
+		} else {
+			expect(readLines).not.toHaveBeenCalled()
+		}
+
+		if (testCase.expectations.sourceCodeDefCalled) {
+			expect(parseSourceCodeDefinitionsForFile).toHaveBeenCalled()
+		} else {
+			expect(parseSourceCodeDefinitionsForFile).not.toHaveBeenCalled()
+		}
+
+		// Verify response content
+		const userMessageContent = getUserMessageContent(cline)
+
+		if (DEBUG) {
+			console.log(`\n=== Test: ${testCase.name} ===`)
+			console.log(`maxReadFileLine: ${testCase.maxReadFileLine}`)
+			console.log("Response content:", JSON.stringify(userMessageContent, null, 2))
+		}
+		const responseLines = userMessageContent[1].text.split("\n")
+
+		if (DEBUG) {
+			console.log(`Number of lines in response: ${responseLines.length}`)
+		}
+
+		expect(userMessageContent.length).toBe(2)
+		expect(userMessageContent[0].text).toBe(`[read_file for '${testFilePath}'] Result:`)
+
+		if (testCase.expectations.expectedContent) {
+			expect(userMessageContent[1].text).toBe(testCase.expectations.expectedContent)
+		}
+
+		if (testCase.expectations.responseValidation) {
+			validateResponseLines(responseLines, testCase.expectations.responseValidation)
+		}
+
+		if (testCase.expectations.truncationMessage) {
+			expect(userMessageContent[1].text).toContain(testCase.expectations.truncationMessage)
+		}
+
+		if (testCase.expectations.includeSourceCodeDef) {
+			expect(userMessageContent[1].text).toContain(sourceCodeDef)
+		}
+	})
+})