fix(editor): Cmd+X cuts current line and Cmd+A highlights every line on trailing newline (#1075)

CHANGELOG.md

@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - New tab via Cmd+T no longer flashes focus back to the previous tab in the same window group
 - Cmd+X with no selection cuts the current line, matching VS Code, Sublime, and Xcode (#1075)
+- Cmd+A on a query ending with a newline now highlights every line, not just the first (#1075)
 
 ### Added
 

LocalPackages/CodeEditTextView/Sources/CodeEditTextView/TextSelectionManager/TextSelectionManager+FillRects.swift

@@ -75,12 +75,26 @@ extension TextSelectionManager {
             let endOfLine = fragmentRange.max <= range.max || range.contains(fragmentRange.max)
             let endOfDocument = intersectionRange.max == layoutManager.lineStorage.length
             let emptyLine = linePosition.range.isEmpty
+            // If the line ends with a line-break character, the selection logically continues onto a
+            // (possibly empty) trailing line and the highlight should extend to the right edge — even
+            // when this fragment is at the end of the document. Without this check, the very last
+            // fragment of a buffer that ends in `\n` collapses to zero width because
+            // `rectForOffset(lineStorage.length)` resolves to the trailing-empty-line position at
+            // the leading edge.
+            let lineEndsWithNewline: Bool = {
+                guard !linePosition.range.isEmpty,
+                      let textStorage = layoutManager.textStorage,
+                      let lineString = textStorage.substring(from: linePosition.range) else {
+                    return false
+                }
+                return LineEnding(line: lineString) != nil
+            }()
 
             // If the selection is at the end of the line, or contains the end of the fragment, and is not the end
             // of the document, we select the entire line to the right of the selection point.
             // true, !true = false, false
             // true, !true = false, true
-            if endOfLine && !(endOfDocument && !emptyLine) {
+            if endOfLine && !(endOfDocument && !emptyLine && !lineEndsWithNewline) {
                 maxRect = CGRect(
                     x: rect.maxX,
                     y: fragmentPosition.yPos + linePosition.yPos,

LocalPackages/CodeEditTextView/Tests/CodeEditTextViewTests/CmdShiftLeftAtEndOfDocumentTests.swift

@@ -0,0 +1,191 @@
+import AppKit
+@testable import CodeEditTextView
+import Testing
+
+/// Regression tests for word-granularity selection extension when the cursor
+/// sits at the very end of the document. Standard macOS NSTextView behavior:
+///   - Cmd+Shift+Left at the end of "select * from products" extends the
+///     selection backward to cover the last word "products".
+///   - Cmd+Left at the end jumps the caret to the start of the last word.
+///
+/// Issue #1075: cursor at end of buffer with no preceding selection cannot
+/// extend selection backward by word.
+@Suite
+@MainActor
+struct CmdShiftLeftAtEndOfDocumentTests {
+    private func makeLaidOutTextView(_ text: String) -> TextView {
+        let textView = TextView(string: text)
+        textView.frame = NSRect(x: 0, y: 0, width: 1_000, height: 1_000)
+        textView.updateFrameIfNeeded()
+        textView.layoutManager.layoutLines(in: NSRect(x: 0, y: 0, width: 1_000, height: 1_000))
+        return textView
+    }
+
+    // MARK: - rangeOfSelection (pure range computation)
+
+    @Test("Cmd+Left at end of single-line query returns range covering last word")
+    func cmdLeftRangeAtEndOfSingleLine() {
+        let textView = makeLaidOutTextView("select * from products")
+        let length = (textView.string as NSString).length
+
+        let range = textView.selectionManager.rangeOfSelection(
+            from: length,
+            direction: .backward,
+            destination: .word
+        )
+
+        #expect(range == NSRange(location: 14, length: 8))
+    }
+
+    @Test("Cmd+Left at end of multi-line query returns range covering last word")
+    func cmdLeftRangeAtEndOfMultiLine() {
+        let textView = makeLaidOutTextView("select *\nfrom products")
+        let length = (textView.string as NSString).length
+
+        let range = textView.selectionManager.rangeOfSelection(
+            from: length,
+            direction: .backward,
+            destination: .word
+        )
+
+        #expect(range == NSRange(location: 14, length: 8))
+    }
+
+    // MARK: - Full moveWordLeftAndModifySelection flow (covers pivot logic)
+
+    @Test("Cmd+Shift+Left at end of single-line query selects the last word")
+    func cmdShiftLeftSelectsLastWordAtEnd() {
+        let textView = makeLaidOutTextView("select * from products")
+        let length = (textView.string as NSString).length
+
+        textView.selectionManager.setSelectedRange(NSRange(location: length, length: 0))
+        textView.moveWordLeftAndModifySelection(nil)
+
+        guard let selection = textView.selectionManager.textSelections.first else {
+            Issue.record("Expected one selection")
+            return
+        }
+        #expect(selection.range == NSRange(location: 14, length: 8))
+    }
+
+    @Test("Cmd+Shift+Left twice at end extends across two words")
+    func cmdShiftLeftTwiceExtendsAcrossTwoWords() {
+        let textView = makeLaidOutTextView("select * from products")
+        let length = (textView.string as NSString).length
+
+        textView.selectionManager.setSelectedRange(NSRange(location: length, length: 0))
+        textView.moveWordLeftAndModifySelection(nil)
+        textView.moveWordLeftAndModifySelection(nil)
+
+        guard let selection = textView.selectionManager.textSelections.first else {
+            Issue.record("Expected one selection")
+            return
+        }
+        // Selection should now cover "from products" — from offset 9 to 22.
+        #expect(selection.range == NSRange(location: 9, length: 13))
+    }
+
+    @Test("Cmd+Left at end moves caret to start of last word")
+    func cmdLeftMovesCaretToStartOfLastWord() {
+        let textView = makeLaidOutTextView("select * from products")
+        let length = (textView.string as NSString).length
+
+        textView.selectionManager.setSelectedRange(NSRange(location: length, length: 0))
+        textView.moveWordLeft(nil)
+
+        guard let selection = textView.selectionManager.textSelections.first else {
+            Issue.record("Expected one selection")
+            return
+        }
+        #expect(selection.range == NSRange(location: 14, length: 0))
+    }
+
+    // MARK: - Pivot reset across separate selection sessions
+
+    /// Reproduces the user's likely workflow: extend selection forward,
+    /// click somewhere else (caret reset), then try to extend backward.
+    /// The stale pivot from the prior session must not leak into the new one.
+    @Test("After click-resetting caret to end, Cmd+Shift+Left selects last word")
+    func clickResetsPivotForBackwardExtension() {
+        let textView = makeLaidOutTextView("select * from products")
+        let length = (textView.string as NSString).length
+
+        // Session 1: cursor at start, extend forward by word.
+        textView.selectionManager.setSelectedRange(NSRange(location: 0, length: 0))
+        textView.moveWordRightAndModifySelection(nil)
+
+        // Session 2: user clicks at end (caret reset).
+        textView.selectionManager.setSelectedRange(NSRange(location: length, length: 0))
+
+        // Cmd+Shift+Left should select the last word.
+        textView.moveWordLeftAndModifySelection(nil)
+
+        guard let selection = textView.selectionManager.textSelections.first else {
+            Issue.record("Expected one selection")
+            return
+        }
+        #expect(selection.range == NSRange(location: 14, length: 8))
+    }
+
+    // MARK: - Cmd+Left / Cmd+Shift+Left at end (line-granularity, NOT word)
+
+    /// Cmd+Left on macOS is `moveToBeginningOfLine:` — line-start, not word.
+    /// At the end of a single-line buffer, the caret should jump to offset 0.
+    @Test("Cmd+Left at end of single-line moves caret to line start (offset 0)")
+    func cmdLeftAtEndJumpsToLineStart() {
+        let textView = makeLaidOutTextView("select * from products")
+        let length = (textView.string as NSString).length
+
+        textView.selectionManager.setSelectedRange(NSRange(location: length, length: 0))
+        textView.moveToBeginningOfLine(nil)
+
+        guard let selection = textView.selectionManager.textSelections.first else {
+            Issue.record("Expected one selection")
+            return
+        }
+        #expect(selection.range == NSRange(location: 0, length: 0))
+    }
+
+    /// Cmd+Shift+Left at the end of a single-line buffer should extend the
+    /// selection backward to offset 0 — selecting the entire line.
+    @Test("Cmd+Shift+Left at end of single-line selects entire line")
+    func cmdShiftLeftAtEndSelectsEntireLine() {
+        let textView = makeLaidOutTextView("select * from products")
+        let length = (textView.string as NSString).length
+
+        textView.selectionManager.setSelectedRange(NSRange(location: length, length: 0))
+        textView.moveToBeginningOfLineAndModifySelection(nil)
+
+        guard let selection = textView.selectionManager.textSelections.first else {
+            Issue.record("Expected one selection")
+            return
+        }
+        #expect(selection.range == NSRange(location: 0, length: length))
+    }
+
+    @Test("Pressing End then Cmd+Shift+Left selects last word")
+    func endThenCmdShiftLeftSelectsLastWord() {
+        let textView = makeLaidOutTextView("select * from products")
+        let length = (textView.string as NSString).length
+
+        // Start somewhere in the middle.
+        textView.selectionManager.setSelectedRange(NSRange(location: 5, length: 0))
+        // Press End — moveToEndOfLine.
+        textView.moveToEndOfLine(nil)
+
+        guard let afterEnd = textView.selectionManager.textSelections.first else {
+            Issue.record("Expected one selection after End")
+            return
+        }
+        #expect(afterEnd.range == NSRange(location: length, length: 0))
+
+        // Now Cmd+Shift+Left.
+        textView.moveWordLeftAndModifySelection(nil)
+
+        guard let selection = textView.selectionManager.textSelections.first else {
+            Issue.record("Expected one selection")
+            return
+        }
+        #expect(selection.range == NSRange(location: 14, length: 8))
+    }
+}