Uppercase first letter of diagnostics

sourcekitd returns diagnostics with the first letter lowercase. Xcode, for example, shows the messages with the first letter uppercases. I think that looks nicer and we should also uppercase the first letter in sourcekit-lsp.

Author: ahoppen

Sources/SourceKitLSP/Swift/Diagnostic.swift

@@ -113,6 +113,19 @@ extension TextEdit {
   }
 }
 
+fileprivate extension String {
+  /// Returns this string with the first letter uppercased.
+  ///
+  /// If the string does not start with a letter, no change is made to it.
+  func withFirstLetterUppercased() -> String {
+    if let firstLetter = self.first {
+      return firstLetter.uppercased() + self.dropFirst()
+    } else {
+      return self
+    }
+  }
+}
+
 extension Diagnostic {
 
   /// Creates a diagnostic from a sourcekitd response dictionary.
@@ -124,7 +137,7 @@ extension Diagnostic {
     let keys = diag.sourcekitd.keys
     let values = diag.sourcekitd.values
 
-    guard let message: String = diag[keys.description] else { return nil }
+    guard let message: String = diag[keys.description]?.withFirstLetterUppercased() else { return nil }
 
     var range: Range<Position>? = nil
     if let line: Int = diag[keys.line],
@@ -248,7 +261,7 @@ extension DiagnosticRelatedInformation {
       return nil
     }
 
-    guard let message: String = diag[keys.description] else { return nil }
+    guard let message: String = diag[keys.description]?.withFirstLetterUppercased() else { return nil }
 
     var actions: [CodeAction]? = nil
     if let skfixits: SKDResponseArray = diag[keys.fixits],

Tests/SourceKitLSPTests/LocalSwiftTests.swift

@@ -535,7 +535,7 @@ final class LocalSwiftTests: XCTestCase {
           // Expected Fix-it: Replace `let a` with `_` because it's never used
           let expectedTextEdit = TextEdit(range: Position(line: 1, utf16index: 7)..<Position(line: 1, utf16index: 7), newText: "?")
           XCTAssertEqual(fixit, CodeAction(
-            title: "chain the optional using '?' to access member 'bigEndian' only for non-'nil' base values",
+            title: "Chain the optional using '?' to access member 'bigEndian' only for non-'nil' base values",
             kind: .quickFix,
             diagnostics: nil,
             edit: WorkspaceEdit(changes: [uri: [expectedTextEdit]], documentChanges: nil),
@@ -550,7 +550,7 @@ final class LocalSwiftTests: XCTestCase {
           // Expected Fix-it: Replace `let a` with `_` because it's never used
           let expectedTextEdit = TextEdit(range: Position(line: 1, utf16index: 7)..<Position(line: 1, utf16index: 7), newText: "!")
           XCTAssertEqual(fixit, CodeAction(
-            title: "force-unwrap using '!' to abort execution if the optional value contains 'nil'",
+            title: "Force-unwrap using '!' to abort execution if the optional value contains 'nil'",
             kind: .quickFix,
             diagnostics: nil,
             edit: WorkspaceEdit(changes: [uri: [expectedTextEdit]], documentChanges: nil),
@@ -691,19 +691,19 @@ final class LocalSwiftTests: XCTestCase {
 
     for fixit in quickFixes {
       if fixit.title.contains("!") {
-        XCTAssert(fixit.title.starts(with: "force-unwrap using '!'"))
+        XCTAssert(fixit.title.starts(with: "Force-unwrap using '!'"))
         expectedTextEdit.newText = "!"
         XCTAssertEqual(fixit.edit, WorkspaceEdit(changes: [uri: [expectedTextEdit]], documentChanges: nil))
       } else {
-        XCTAssert(fixit.title.starts(with: "chain the optional using '?'"))
+        XCTAssert(fixit.title.starts(with: "Chain the optional using '?'"))
         expectedTextEdit.newText = "?"
         XCTAssertEqual(fixit.edit, WorkspaceEdit(changes: [uri: [expectedTextEdit]], documentChanges: nil))
       }
       XCTAssertEqual(fixit.kind, .quickFix)
       XCTAssertEqual(fixit.diagnostics?.count, 1)
       XCTAssertEqual(fixit.diagnostics?.first?.severity, .error)
       XCTAssertEqual(fixit.diagnostics?.first?.range, Range(Position(line: 1, utf16index: 6)))
-      XCTAssert(fixit.diagnostics?.first?.message.starts(with: "value of optional type") == true)
+      XCTAssert(fixit.diagnostics?.first?.message.starts(with: "Value of optional type") == true)
     }
   }
 
@@ -788,7 +788,7 @@ final class LocalSwiftTests: XCTestCase {
     XCTAssertEqual(quickFixes.count, 1)
     guard let fixit = quickFixes.first  else { return }
 
-    XCTAssertEqual(fixit.title, "use 'new(_:hotness:)' instead")
+    XCTAssertEqual(fixit.title, "Use 'new(_:hotness:)' instead")
     XCTAssertEqual(fixit.diagnostics?.count, 1)
     XCTAssert(fixit.diagnostics?.first?.message.contains("is deprecated") == true)
     XCTAssertEqual(fixit.edit?.changes?[uri], [