Update sortImports to support --import-grouping length,alpha (#2463)

Co-authored-by: calda <1811727+calda@users.noreply.github.com>

Sources/Rules/SortImports.swift

@@ -84,7 +84,13 @@ extension Formatter {
                 }
 
                 if grouping.contains(.length) {
-                    return lhs.module.count < rhs.module.count
+                    if lhs.module.count != rhs.module.count {
+                        return lhs.module.count < rhs.module.count
+                    }
+                    if grouping.contains(.alpha) {
+                        return lhs < rhs
+                    }
+                    return false
                 }
                 // Default to alphabetical
                 return lhs < rhs

Tests/Rules/SortImportsTests.swift

@@ -596,4 +596,36 @@ final class SortImportsTests: XCTestCase {
         let options = FormatOptions(importGrouping: [.length, .testableLast])
         testFormatting(for: input, output, rule: .sortImports, options: options)
     }
+
+    func testLengthThenAlphaSortImports() {
+        let input = """
+        import Module
+        import Foo
+        import Bar
+        import Ab
+        """
+        let output = """
+        import Ab
+        import Bar
+        import Foo
+        import Module
+        """
+        let options = FormatOptions(importGrouping: [.length, .alpha])
+        testFormatting(for: input, output, rule: .sortImports, options: options)
+    }
+
+    func testLengthThenAlphaSortImportsWithSameLength() {
+        let input = """
+        import Zed
+        import Foo
+        import Bar
+        """
+        let output = """
+        import Bar
+        import Foo
+        import Zed
+        """
+        let options = FormatOptions(importGrouping: [.length, .alpha])
+        testFormatting(for: input, output, rule: .sortImports, options: options)
+    }
 }