Fix Crash At End Of File

Author: thecoolwinter

Example/CodeEditSourceEditorExample/CodeEditSourceEditorExample.xcodeproj/xcshareddata/xcschemes/CodeEditSourceEditorExample.xcscheme

@@ -29,6 +29,18 @@
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
       shouldUseLaunchSchemeArgsEnv = "YES"
       shouldAutocreateTestPlan = "YES">
+      <Testables>
+         <TestableReference
+            skipped = "NO">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "CodeEditSourceEditorTests"
+               BuildableName = "CodeEditSourceEditorTests"
+               BlueprintName = "CodeEditSourceEditorTests"
+               ReferencedContainer = "container:../..">
+            </BuildableReference>
+         </TestableReference>
+      </Testables>
    </TestAction>
    <LaunchAction
       buildConfiguration = "Debug"

…geStore/StyledRangeStore+Internals.swift …ngeStore/StyledRangeStore+Coalesce.swiftSources/CodeEditSourceEditor/Highlighting/StyledRangeContainer/StyledRangeStore/StyledRangeStore+Internals.swift renamed to Sources/CodeEditSourceEditor/Highlighting/StyledRangeContainer/StyledRangeStore/StyledRangeStore+Coalesce.swift Sources/CodeEditSourceEditor/Highlighting/StyledRangeContainer/StyledRangeStore/StyledRangeStore+Internals.swift renamed to Sources/CodeEditSourceEditor/Highlighting/StyledRangeContainer/StyledRangeStore/StyledRangeStore+Coalesce.swift

@@ -7,15 +7,6 @@
 
 import _RopeModule
 
-extension StyledRangeStore {
-    /// Finds a Rope index, given a string offset.
-    /// - Parameter offset: The offset to query for.
-    /// - Returns: The index of the containing element in the rope.
-    func findIndex(at offset: Int) -> (index: Index, remaining: Int) {
-        _guts.find(at: offset, in: OffsetMetric(), preferEnd: false)
-    }
-}
-
 extension StyledRangeStore {
     /// Coalesce items before and after the given range.
     ///
@@ -32,7 +23,7 @@ extension StyledRangeStore {
         }
 
         index = findIndex(at: range.lowerBound).index
-        if index > _guts.startIndex && _guts.count > 1 {
+        if index > _guts.startIndex && index < _guts.endIndex && _guts.count > 1 {
             index = _guts.index(before: index)
             coalesceRunAfter(index: &index)
         }

Sources/CodeEditSourceEditor/Highlighting/StyledRangeContainer/StyledRangeStore/StyledRangeStore+FindIndex.swift

@@ -0,0 +1,15 @@
+//
+//  StyledRangeStore+FindIndex.swift
+//  CodeEditSourceEditor
+//
+//  Created by Khan Winter on 1/6/25.
+//
+
+extension StyledRangeStore {
+    /// Finds a Rope index, given a string offset.
+    /// - Parameter offset: The offset to query for.
+    /// - Returns: The index of the containing element in the rope.
+    func findIndex(at offset: Int) -> (index: Index, remaining: Int) {
+        _guts.find(at: offset, in: OffsetMetric(), preferEnd: false)
+    }
+}

Tests/CodeEditSourceEditorTests/Highlighting/StyledRangeStoreTests.swift

@@ -36,6 +36,20 @@ final class StyledRangeStoreTests: XCTestCase {
         XCTAssertEqual(store.count, 1, "Failed to coalesce")
     }
 
+    func test_storageRemoveSingleCharacterFromEnd() {
+        let store = StyledRangeStore(documentLength: 10)
+        store.set( // Test that we can delete a character associated with a single syntax run too
+            runs: [
+                .empty(length: 8),
+                .init(length: 1, modifiers: [.abstract]),
+                .init(length: 1, modifiers: [.declaration])],
+            for: 0..<10
+        )
+        store.storageUpdated(replacedCharactersIn: 9..<10, withCount: 0)
+        XCTAssertEqual(store.length, 9, "Failed to remove correct range")
+        XCTAssertEqual(store.count, 2)
+    }
+
     func test_storageRemoveFromBeginning() {
         let store = StyledRangeStore(documentLength: 100)
         store.storageUpdated(replacedCharactersIn: 0..<15, withCount: 0)