feat: add multiline command converter to fix terminal hanging issue

- Add multilineCommandConverter utility to convert multiline commands to single-line
- Integrate converter into executeCommandTool with configurable setting
- Add comprehensive tests for various shell constructs and edge cases
- Handles POSIX shells (bash, zsh, fish) and PowerShell
- Preserves functionality for Here Documents and other non-convertible patterns

Fixes #7123

src/core/tools/executeCommandTool.ts

@@ -17,6 +17,7 @@ import { TerminalRegistry } from "../../integrations/terminal/TerminalRegistry"
 import { Terminal } from "../../integrations/terminal/Terminal"
 import { Package } from "../../shared/package"
 import { t } from "../../i18n"
+import { convertMultilineToSingleLine, shouldConvertCommand } from "../../utils/multilineCommandConverter"
 
 class ShellIntegrationError extends Error {}
 
@@ -54,12 +55,38 @@ export async function executeCommandTool(
 			task.consecutiveMistakeCount = 0
 
 			command = unescapeHtmlEntities(command) // Unescape HTML entities.
+
+			// Convert multiline commands to single line if enabled and applicable
+			const multilineConversionEnabled = vscode.workspace
+				.getConfiguration(Package.name)
+				.get<boolean>("multilineCommandConversion", true)
+
+			let originalCommand = command
+			let conversionApplied = false
+
+			if (multilineConversionEnabled && shouldConvertCommand(command)) {
+				const conversionResult = convertMultilineToSingleLine(command)
+				if (conversionResult.success) {
+					command = conversionResult.command
+					conversionApplied = true
+				} else {
+					// Log conversion failure but continue with original command
+					console.log(`[executeCommandTool] Multiline conversion failed: ${conversionResult.reason}`)
+				}
+			}
+
+			// Show the command that will be executed (converted or original)
 			const didApprove = await askApproval("command", command)
 
 			if (!didApprove) {
 				return
 			}
 
+			// If conversion was applied, log it (don't notify user to avoid disruption)
+			if (conversionApplied) {
+				console.log(`[executeCommandTool] Multiline command converted to single-line for execution`)
+			}
+
 			const executionId = task.lastMessageTs?.toString() ?? Date.now().toString()
 			const provider = await task.providerRef.deref()
 			const providerState = await provider?.getState()

src/utils/__tests__/multilineCommandConverter.spec.ts

@@ -0,0 +1,333 @@
+// npx vitest run src/utils/__tests__/multilineCommandConverter.spec.ts
+
+import { describe, it, expect } from "vitest"
+import { convertMultilineToSingleLine, shouldConvertCommand } from "../multilineCommandConverter"
+
+describe("multilineCommandConverter", () => {
+	describe("shouldConvertCommand", () => {
+		it("should return false for single-line commands", () => {
+			expect(shouldConvertCommand('echo "hello world"')).toBe(false)
+			expect(shouldConvertCommand("ls -la")).toBe(false)
+		})
+
+		it("should return true for multiline commands", () => {
+			expect(shouldConvertCommand('echo "hello"\necho "world"')).toBe(true)
+		})
+
+		it("should return false for Here Documents", () => {
+			const hereDoc = `cat <<EOF
+Hello World
+EOF`
+			expect(shouldConvertCommand(hereDoc)).toBe(false)
+		})
+	})
+
+	describe("convertMultilineToSingleLine", () => {
+		describe("Basic functionality", () => {
+			it("should handle simple multiline commands", () => {
+				const input = `echo "hello"
+echo "world"`
+				const result = convertMultilineToSingleLine(input)
+				expect(result.success).toBe(true)
+				expect(result.command).toBe('echo "hello" ; echo "world"')
+			})
+
+			it("should handle line continuations with backslash", () => {
+				const input = `echo "This is a very \\
+long command that \\
+spans multiple lines"`
+				const result = convertMultilineToSingleLine(input)
+				expect(result.success).toBe(true)
+				expect(result.command).toBe('echo "This is a very long command that spans multiple lines"')
+			})
+
+			it("should handle pipes at end of line", () => {
+				const input = `cat file.txt |
+grep "pattern" |
+sort`
+				const result = convertMultilineToSingleLine(input)
+				expect(result.success).toBe(true)
+				// Pipes don't need semicolons
+				expect(result.command).toBe('cat file.txt | grep "pattern" | sort')
+			})
+
+			it("should handle logical operators", () => {
+				const input = `command1 &&
+command2 ||
+command3`
+				const result = convertMultilineToSingleLine(input)
+				expect(result.success).toBe(true)
+				// Logical operators don't need semicolons
+				expect(result.command).toBe("command1 && command2 || command3")
+			})
+
+			it("should handle empty lines", () => {
+				const input = `echo "start"
+
+echo "middle"
+
+echo "end"`
+				const result = convertMultilineToSingleLine(input)
+				expect(result.success).toBe(true)
+				expect(result.command).toBe('echo "start" ; echo "middle" ; echo "end"')
+			})
+
+			it("should return original for single-line commands", () => {
+				const input = 'echo "hello world"'
+				const result = convertMultilineToSingleLine(input)
+				expect(result.success).toBe(true)
+				expect(result.command).toBe(input)
+			})
+		})
+
+		describe("Shell constructs", () => {
+			it("should handle if statements", () => {
+				const input = `if [ -f file.txt ]
+then
+  echo "File exists"
+else
+  echo "File not found"
+fi`
+				const result = convertMultilineToSingleLine(input)
+				expect(result.success).toBe(true)
+				// Basic conversion joins with semicolons
+				expect(result.command).toContain("if [ -f file.txt ]")
+				expect(result.command).toContain("then")
+				expect(result.command).toContain('echo "File exists"')
+				expect(result.command).toContain("else")
+				expect(result.command).toContain('echo "File not found"')
+				expect(result.command).toContain("fi")
+			})
+
+			it("should handle for loops", () => {
+				const input = `for i in 1 2 3
+do
+  echo $i
+done`
+				const result = convertMultilineToSingleLine(input)
+				expect(result.success).toBe(true)
+				expect(result.command).toContain("for i in 1 2 3")
+				expect(result.command).toContain("do")
+				expect(result.command).toContain("echo $i")
+				expect(result.command).toContain("done")
+			})
+
+			it("should handle while loops", () => {
+				const input = `while [ $count -lt 10 ]
+do
+  echo $count
+  count=$((count + 1))
+done`
+				const result = convertMultilineToSingleLine(input)
+				expect(result.success).toBe(true)
+				expect(result.command).toContain("while [ $count -lt 10 ]")
+				expect(result.command).toContain("do")
+				expect(result.command).toContain("echo $count")
+				expect(result.command).toContain("count=$((count + 1))")
+				expect(result.command).toContain("done")
+			})
+
+			it("should handle functions", () => {
+				const input = `function myFunc() {
+  echo "Hello"
+  return 0
+}`
+				const result = convertMultilineToSingleLine(input)
+				expect(result.success).toBe(true)
+				expect(result.command).toContain("function myFunc() {")
+				expect(result.command).toContain('echo "Hello"')
+				expect(result.command).toContain("return 0")
+				expect(result.command).toContain("}")
+			})
+
+			it("should handle command grouping", () => {
+				const input = `(
+  cd /tmp
+  ls -la
+)`
+				const result = convertMultilineToSingleLine(input)
+				expect(result.success).toBe(true)
+				expect(result.command).toContain("(")
+				expect(result.command).toContain("cd /tmp")
+				expect(result.command).toContain("ls -la")
+				expect(result.command).toContain(")")
+			})
+		})
+
+		describe("PowerShell", () => {
+			it("should handle simple PowerShell commands", () => {
+				const input = `Write-Host "Hello"
+Write-Host "World"`
+				const result = convertMultilineToSingleLine(input)
+				expect(result.success).toBe(true)
+				expect(result.command).toBe('Write-Host "Hello" ; Write-Host "World"')
+			})
+
+			it("should handle line continuations with backtick", () => {
+				const input = `Get-ChildItem \`
+  -Path "C:\\Users" \`
+  -Recurse`
+				const result = convertMultilineToSingleLine(input)
+				expect(result.success).toBe(true)
+				expect(result.command).toBe('Get-ChildItem -Path "C:\\Users" -Recurse')
+			})
+
+			it("should handle pipes in PowerShell", () => {
+				const input = `Get-Process |
+  Where-Object {$_.CPU -gt 10} |
+  Sort-Object CPU`
+				const result = convertMultilineToSingleLine(input)
+				expect(result.success).toBe(true)
+				expect(result.command).toBe("Get-Process | Where-Object {$_.CPU -gt 10} | Sort-Object CPU")
+			})
+
+			it("should handle PowerShell if statements", () => {
+				const input = `if ($true) {
+  Write-Host "True"
+} else {
+  Write-Host "False"
+}`
+				const result = convertMultilineToSingleLine(input)
+				expect(result.success).toBe(true)
+				expect(result.command).toContain("if ($true) {")
+				expect(result.command).toContain('Write-Host "True"')
+				expect(result.command).toContain("} else {")
+				expect(result.command).toContain('Write-Host "False"')
+			})
+
+			it("should handle PowerShell foreach loops", () => {
+				const input = `foreach ($item in $items) {
+  Write-Host $item
+}`
+				const result = convertMultilineToSingleLine(input)
+				expect(result.success).toBe(true)
+				expect(result.command).toContain("foreach ($item in $items) {")
+				expect(result.command).toContain("Write-Host $item")
+				expect(result.command).toContain("}")
+			})
+		})
+
+		describe("Here Documents", () => {
+			it("should not convert Here Documents", () => {
+				const input = `cat <<EOF
+This is a here document
+It should not be converted
+EOF`
+				const result = convertMultilineToSingleLine(input)
+				expect(result.success).toBe(false)
+				expect(result.command).toBe(input)
+				expect(result.reason).toContain("Here Document")
+			})
+
+			it("should detect various Here Document formats", () => {
+				const inputs = [
+					`cat <<-EOF\nContent\nEOF`,
+					`cat <<"END"\nContent\nEND`,
+					`cat <<'MARKER'\nContent\nMARKER`,
+					`python <<SCRIPT\nprint("hello")\nSCRIPT`,
+				]
+
+				inputs.forEach((input) => {
+					const result = convertMultilineToSingleLine(input)
+					expect(result.success).toBe(false)
+					expect(result.reason).toContain("Here Document")
+				})
+			})
+		})
+
+		describe("Edge cases", () => {
+			it("should handle commands with semicolons already present", () => {
+				const input = `echo "one";
+echo "two";
+echo "three"`
+				const result = convertMultilineToSingleLine(input)
+				expect(result.success).toBe(true)
+				// Should not add extra semicolons
+				expect(result.command).toBe('echo "one"; echo "two"; echo "three"')
+			})
+
+			it("should handle mixed line endings", () => {
+				const input = 'echo "one"\r\necho "two"\necho "three"'
+				const result = convertMultilineToSingleLine(input)
+				expect(result.success).toBe(true)
+				expect(result.command).toContain('echo "one"')
+				expect(result.command).toContain('echo "two"')
+				expect(result.command).toContain('echo "three"')
+			})
+
+			it("should handle very long commands", () => {
+				const lines = []
+				for (let i = 0; i < 100; i++) {
+					lines.push(`echo "Line ${i}"`)
+				}
+				const input = lines.join("\n")
+				const result = convertMultilineToSingleLine(input)
+				expect(result.success).toBe(true)
+				expect(result.command).toContain('echo "Line 0"')
+				expect(result.command).toContain('echo "Line 99"')
+				expect(result.command.split(";").length).toBeGreaterThan(50)
+			})
+		})
+
+		describe("Real-world examples", () => {
+			it("should handle a complex bash script", () => {
+				const input = `if [ -d "$DIR" ]; then
+  echo "Processing directory: $DIR"
+  for file in "$DIR"/*.txt; do
+    if [ -f "$file" ]; then
+      echo "Found: $(basename "$file")"
+      cat "$file" |
+        grep -E "pattern" |
+        sort > output.txt
+    fi
+  done
+else
+  echo "Directory not found"
+fi`
+				const result = convertMultilineToSingleLine(input)
+				expect(result.success).toBe(true)
+				expect(result.command).toContain('if [ -d "$DIR" ]')
+				expect(result.command).toContain('for file in "$DIR"/*.txt')
+				expect(result.command).toContain('grep -E "pattern"')
+				expect(result.command).toContain("sort > output.txt")
+			})
+
+			it("should handle a git command with multiple lines", () => {
+				const input = `git log --oneline \\
+  --graph \\
+  --decorate \\
+  --all`
+				const result = convertMultilineToSingleLine(input)
+				expect(result.success).toBe(true)
+				expect(result.command).toBe("git log --oneline --graph --decorate --all")
+			})
+
+			it("should handle a docker command", () => {
+				const input = `docker run \\
+  -d \\
+  --name mycontainer \\
+  -p 8080:80 \\
+  -v /host/path:/container/path \\
+  nginx:latest`
+				const result = convertMultilineToSingleLine(input)
+				expect(result.success).toBe(true)
+				expect(result.command).toBe(
+					"docker run -d --name mycontainer -p 8080:80 -v /host/path:/container/path nginx:latest",
+				)
+			})
+
+			it("should handle a curl command", () => {
+				const input = `curl -X POST \\
+  -H "Content-Type: application/json" \\
+  -H "Authorization: Bearer token" \\
+  -d '{"key": "value"}' \\
+  https://api.example.com/endpoint`
+				const result = convertMultilineToSingleLine(input)
+				expect(result.success).toBe(true)
+				expect(result.command).toBe(
+					'curl -X POST -H "Content-Type: application/json" -H "Authorization: Bearer token" -d \'{"key": "value"}\' https://api.example.com/endpoint',
+				)
+			})
+		})
+	})
+})

src/utils/multilineCommandConverter.ts

@@ -0,0 +1,98 @@
+/**
+ * Utility to convert multiline terminal commands into single-line equivalents
+ * to prevent terminal hanging issues when executing multiline commands.
+ *
+ * Supports POSIX shells (bash, zsh, fish) and PowerShell.
+ */
+
+export interface ConversionResult {
+	success: boolean
+	command: string
+	reason?: string
+}
+
+/**
+ * Detects if a command contains a Here Document which cannot be converted to single line
+ */
+function hasHereDocument(command: string): boolean {
+	// Check for Here Document patterns: <<EOF, <<-EOF, <<"EOF", <<'EOF'
+	const hereDocPattern = /<<-?\s*(['"]?)(\w+)\1/
+	return hereDocPattern.test(command)
+}
+
+/**
+ * Main function to convert multiline commands to single line
+ * Uses a simple approach: join lines with semicolons for most cases
+ */
+export function convertMultilineToSingleLine(command: string): ConversionResult {
+	// Check if command is already single line
+	if (!command.includes("\n")) {
+		return { success: true, command }
+	}
+
+	// Check for unconvertible patterns
+	if (hasHereDocument(command)) {
+		return {
+			success: false,
+			command,
+			reason: "Command contains a Here Document which cannot be converted to single line",
+		}
+	}
+
+	try {
+		// Simple approach: handle common patterns
+		let result = command
+
+		// Handle line continuations (backslash at end of line)
+		result = result.replace(/\\\n\s*/g, " ")
+
+		// Handle line continuations (backtick at end of line for PowerShell)
+		result = result.replace(/`\n\s*/g, " ")
+
+		// Split into lines
+		const lines = result
+			.split("\n")
+			.map((line) => line.trim())
+			.filter((line) => line)
+
+		// Join lines with appropriate separators
+		const joined = lines.join(" ; ")
+
+		// Clean up multiple semicolons and spaces
+		result = joined
+			.replace(/;\s*;/g, ";")
+			.replace(/\s+/g, " ")
+			.replace(/\{\s*;/g, "{") // Remove semicolon after opening brace
+			.replace(/\(\s*;/g, "(") // Remove semicolon after opening paren
+			.replace(/\|\s*;/g, "|") // Remove semicolon after pipe
+			.replace(/&&\s*;/g, "&&") // Remove semicolon after &&
+			.replace(/\|\|\s*;/g, "||") // Remove semicolon after ||
+			.trim()
+
+		return { success: true, command: result }
+	} catch (error) {
+		// If conversion fails, return original command
+		return {
+			success: false,
+			command,
+			reason: `Conversion failed: ${error.message}`,
+		}
+	}
+}
+
+/**
+ * Determines if a command should be converted based on configuration
+ */
+export function shouldConvertCommand(command: string): boolean {
+	// Always convert if command has multiple lines
+	if (!command.includes("\n")) {
+		return false
+	}
+
+	// Check for patterns that should not be converted
+	if (hasHereDocument(command)) {
+		return false
+	}
+
+	return true
+}