Improve word wrapping

Sources/SwiftlyCore/StringExtensions.swift

@@ -0,0 +1,64 @@
+/// A description
+extension String {
+    /// Wraps text to fit within specified column width
+    ///
+    /// This method reformats the string to ensure each line fits within the specified column width,
+    /// attempting to break at spaces when possible to avoid splitting words.
+    ///
+    /// - Parameters:
+    ///   - columns: Maximum width (in characters) for each line
+    ///   - wrappingIndent: Number of spaces to add at the beginning of each wrapped line (not the first line)
+    ///
+    /// - Returns: A new string with appropriate line breaks to maintain the specified column width
+    func wrapText(to columns: Int, wrappingIndent: Int = 0) -> String {
+        let effectiveColumns = columns - wrappingIndent
+        guard effectiveColumns > 0 else { return self }
+
+        var result: [Substring] = []
+        var currentIndex = self.startIndex
+
+        while currentIndex < self.endIndex {
+            let nextChunk = self[currentIndex...].prefix(effectiveColumns)
+
+            // Handle line breaks in the current chunk
+            if let lastLineBreak = nextChunk.lastIndex(of: "\n") {
+                result.append(
+                    contentsOf: self[currentIndex..<lastLineBreak].split(
+                        separator: "\n", omittingEmptySubsequences: false
+                    ))
+                currentIndex = self.index(after: lastLineBreak)
+                continue
+            }
+
+            // We've reached the end of the string
+            if nextChunk.endIndex == self.endIndex {
+                result.append(self[currentIndex...])
+                break
+            }
+
+            // Try to break at the last space within the column limit
+            if let lastSpace = nextChunk.lastIndex(of: " ") {
+                result.append(self[currentIndex..<lastSpace])
+                currentIndex = self.index(after: lastSpace)
+                continue
+            }
+
+            // If no space in the chunk, find the next space after column limit
+            if let nextSpace = self[currentIndex...].firstIndex(of: " ") {
+                result.append(self[currentIndex..<nextSpace])
+                currentIndex = self.index(after: nextSpace)
+                continue
+            }
+
+            // No spaces left in the string - add the rest and finish
+            result.append(self[currentIndex...])
+            break
+        }
+
+        // Apply indentation to wrapped lines and join them
+        return
+            result
+                .map { $0.isEmpty ? $0 : String(repeating: " ", count: wrappingIndent) + $0 }
+                .joined(separator: "\n")
+    }
+}

Sources/SwiftlyCore/SwiftlyCore.swift

@@ -47,15 +47,38 @@ public struct SwiftlyCoreContext: Sendable {
     /// Pass the provided string to the set output handler if any.
     /// If no output handler has been set, just print to stdout.
     public func print(_ string: String = "", terminator: String? = nil) async {
+        // Get terminal size or use default width
+        let terminalWidth = self.getTerminalWidth()
+        let wrappedString = string.isEmpty ? string : string.wrapText(to: terminalWidth)
+
         guard let handler = self.outputHandler else {
             if let terminator {
-                Swift.print(string, terminator: terminator)
+                Swift.print(wrappedString, terminator: terminator)
             } else {
-                Swift.print(string)
+                Swift.print(wrappedString)
             }
             return
         }
-        await handler.handleOutputLine(string + (terminator ?? ""))
+        await handler.handleOutputLine(wrappedString + (terminator ?? ""))
+    }
+
+    /// Detects the terminal width in columns
+    private func getTerminalWidth() -> Int {
+#if os(macOS) || os(Linux)
+        var size = winsize()
+#if os(OpenBSD)
+        // TIOCGWINSZ is a complex macro, so we need the flattened value.
+        let tiocgwinsz = UInt(0x4008_7468)
+        let result = ioctl(STDOUT_FILENO, tiocgwinsz, &size)
+#else
+        let result = ioctl(STDOUT_FILENO, UInt(TIOCGWINSZ), &size)
+#endif
+
+        if result == 0 && Int(size.ws_col) > 0 {
+            return Int(size.ws_col)
+        }
+#endif
+        return 80 // Default width if terminal size detection fails
     }
 
     public func readLine(prompt: String) async -> String? {
@@ -75,10 +98,13 @@ public struct SwiftlyCoreContext: Sendable {
         }
 
         while true {
-            let answer = (await self.readLine(prompt: "Proceed? \(options)") ?? (defaultBehavior ? "y" : "n")).lowercased()
+            let answer =
+                (await self.readLine(prompt: "Proceed? \(options)")
+                        ?? (defaultBehavior ? "y" : "n")).lowercased()
 
             guard ["y", "n", ""].contains(answer) else {
-                await self.print("Please input either \"y\" or \"n\", or press ENTER to use the default.")
+                await self.print(
+                    "Please input either \"y\" or \"n\", or press ENTER to use the default.")
                 continue
             }
 

Tests/SwiftlyTests/StringExtensionsTests.swift

@@ -0,0 +1,208 @@
+@testable import SwiftlyCore
+import Testing
+import XCTest
+
+@Suite struct StringExtensionsTests {
+    @Test("Basic text wrapping at column width")
+    func testBasicWrapping() {
+        let input = "This is a simple test string that should be wrapped at the specified width."
+        let expected = """
+        This is a
+        simple test
+        string that
+        should be
+        wrapped at
+        the
+        specified
+        width.
+        """
+
+        XCTAssertEqual(input.wrapText(to: 10), expected)
+    }
+
+    @Test("Preserve existing line breaks")
+    func testPreserveLineBreaks() {
+        let input = "First line\nSecond line\nThird line"
+        let expected = "First line\nSecond line\nThird line"
+
+        XCTAssertEqual(input.wrapText(to: 20), expected)
+    }
+
+    @Test("Combine wrapping with existing line breaks")
+    func testCombineWrappingAndLineBreaks() {
+        let input = "Short line\nThis is a very long line that needs to be wrapped\nAnother short line"
+        let expected = """
+        Short line
+        This is a very
+        long line that
+        needs to be
+        wrapped
+        Another short line
+        """
+
+        XCTAssertEqual(input.wrapText(to: 15), expected)
+    }
+
+    @Test("Words longer than column width")
+    func testLongWords() {
+        let input = "This has a supercalifragilisticexpialidocious word"
+        let expected = """
+        This has a
+        supercalifragilisticexpialidocious
+        word
+        """
+
+        XCTAssertEqual(input.wrapText(to: 10), expected)
+    }
+
+    @Test("Text with no spaces")
+    func testNoSpaces() {
+        let input = "ThisIsALongStringWithNoSpaces"
+        let expected = "ThisIsALongStringWithNoSpaces"
+
+        XCTAssertEqual(input.wrapText(to: 10), expected)
+    }
+
+    @Test("Empty string")
+    func testEmptyString() {
+        let input = ""
+        let expected = ""
+
+        XCTAssertEqual(input.wrapText(to: 10), expected)
+    }
+
+    @Test("Single character")
+    func testSingleCharacter() {
+        let input = "X"
+        let expected = "X"
+
+        XCTAssertEqual(input.wrapText(to: 10), expected)
+    }
+
+    @Test("Single line not exceeding width")
+    func testSingleLineNoWrapping() {
+        let input = "Short text"
+        let expected = "Short text"
+
+        XCTAssertEqual(input.wrapText(to: 10), expected)
+    }
+
+    @Test("Wrapping with indentation")
+    func testWrappingWithIndent() {
+        let input = "This is text that should be wrapped with indentation on new lines."
+        let expected = """
+        This is
+          text that
+          should be
+          wrapped
+          with
+          indentation
+          on new
+          lines.
+        """
+
+        XCTAssertEqual(input.wrapText(to: 10, wrappingIndent: 2), expected)
+    }
+
+    @Test("Zero or negative column width")
+    func testZeroOrNegativeWidth() {
+        let input = "This should not be wrapped"
+
+        XCTAssertEqual(input.wrapText(to: 0), input)
+        XCTAssertEqual(input.wrapText(to: -5), input)
+    }
+
+    @Test("Very narrow column width")
+    func testVeryNarrowWidth() {
+        let input = "A B C"
+        let expected = "A\nB\nC"
+
+        XCTAssertEqual(input.wrapText(to: 1), expected)
+    }
+
+    @Test("Special characters")
+    func testSpecialCharacters() {
+        let input = "Special !@#$%^&*() chars"
+        let expected = """
+        Special
+        !@#$%^&*()
+        chars
+        """
+
+        XCTAssertEqual(input.wrapText(to: 10), expected)
+    }
+
+    @Test("Unicode characters")
+    func testUnicodeCharacters() {
+        let input = "Unicode: 你好世界 😀🚀🌍"
+        let expected = """
+        Unicode: 你好世界
+        😀🚀🌍
+        """
+
+        XCTAssertEqual(input.wrapText(to: 15), expected)
+    }
+
+    @Test("Irregular spacing")
+    func testIrregularSpacing() {
+        let input = "Words  with    irregular     spacing"
+        let expected = """
+        Words  with
+        irregular
+        spacing
+        """
+
+        XCTAssertEqual(input.wrapText(to: 10), expected)
+    }
+
+    @Test("Tab characters")
+    func testTabCharacters() {
+        let input = "Text\twith\ttabs"
+        let expected = """
+        Text\twith
+        \ttabs
+        """
+
+        XCTAssertEqual(input.wrapText(to: 10), expected)
+    }
+
+    @Test("Trailing spaces")
+    func testTrailingSpaces() {
+        let input = "Text with  trailing spaces  "
+        let expected = """
+        Text with
+        trailing
+        spaces
+        """
+
+        XCTAssertEqual(input.wrapText(to: 10), expected)
+    }
+
+    @Test("Leading spaces")
+    func testLeadingSpaces() {
+        let input = "  Leading spaces with text"
+        let expected = """
+          Leading
+        spaces with
+        text
+        """
+
+        XCTAssertEqual(input.wrapText(to: 10), expected)
+    }
+
+    @Test("Multiple consecutive newlines")
+    func testMultipleNewlines() {
+        let input = "First\n\nSecond\n\n\nThird"
+        let expected = "First\n\nSecond\n\n\nThird"
+
+        XCTAssertEqual(input.wrapText(to: 10), expected)
+    }
+
+    @Test("Edge case - exactly at column width")
+    func testExactColumnWidth() {
+        let input = "1234567890 abcdefghij"
+        let expected = "1234567890\nabcdefghij"
+
+        XCTAssertEqual(input.wrapText(to: 10), expected)
+    }
+}