If the unshipped API file is empty, treat it as ending with a blank line

Author: sharwell

PublicApiAnalyzer/PublicApiAnalyzer.CodeFixes/ApiDesign/DeclarePublicAPIFix.cs

@@ -87,7 +87,8 @@ private static SourceText RemoveSymbolNamesFromSourceText(SourceText sourceText,
 
             var sortedLines = newLines.OrderBy(s => s, StringComparer.Ordinal);
 
-            var newSourceText = sourceText.Replace(new TextSpan(0, sourceText.Length), string.Join(Environment.NewLine, sortedLines) + GetEndOfFileText(sourceText));
+            string newText = sortedLines.Any() ? string.Join(Environment.NewLine, sortedLines) + GetEndOfFileText(sourceText) : string.Empty;
+            var newSourceText = sourceText.Replace(new TextSpan(0, sourceText.Length), newText);
             return newSourceText;
         }
 
@@ -117,7 +118,8 @@ private static string GetEndOfFileText(SourceText sourceText)
         {
             if (sourceText.Length == 0)
             {
-                return string.Empty;
+                // An empty file is treated as though it ends with an empty line
+                return Environment.NewLine;
             }
 
             var lastLine = sourceText.Lines[sourceText.Lines.Count - 1];

PublicApiAnalyzer/PublicApiAnalyzer.Test/ApiDesign/DeclarePublicAPIAnalyzerTests.cs

@@ -41,7 +41,7 @@ private C() { }
             var expected = this.CSharpDiagnostic(DeclarePublicAPIAnalyzer.DeclareNewApiRule).WithArguments("C").WithLocation(2, 14);
             await this.VerifyCSharpDiagnosticAsync(source, expected, CancellationToken.None).ConfigureAwait(false);
 
-            string fixedApi = "C";
+            string fixedApi = "C" + Environment.NewLine;
             var updatedApi = await this.GetUpdatedApiAsync(source, 0, CancellationToken.None).ConfigureAwait(false);
 
             Assert.Equal(fixedApi, updatedApi.ToString());
@@ -89,27 +89,27 @@ public void Method() { }
 
             await this.VerifyCSharpDiagnosticAsync(source, expected, CancellationToken.None).ConfigureAwait(false);
 
-            string fixedApi = "C";
+            string fixedApi = "C" + Environment.NewLine;
             var updatedApi = await this.GetUpdatedApiAsync(source, 0, CancellationToken.None).ConfigureAwait(false);
             Assert.Equal(fixedApi, updatedApi.ToString());
 
-            fixedApi = "C.C() -> void";
+            fixedApi = "C.C() -> void" + Environment.NewLine;
             updatedApi = await this.GetUpdatedApiAsync(source, 1, CancellationToken.None).ConfigureAwait(false);
             Assert.Equal(fixedApi, updatedApi.ToString());
 
-            fixedApi = "C.Field -> int";
+            fixedApi = "C.Field -> int" + Environment.NewLine;
             updatedApi = await this.GetUpdatedApiAsync(source, 2, CancellationToken.None).ConfigureAwait(false);
             Assert.Equal(fixedApi, updatedApi.ToString());
 
-            fixedApi = "C.Property.get -> int";
+            fixedApi = "C.Property.get -> int" + Environment.NewLine;
             updatedApi = await this.GetUpdatedApiAsync(source, 3, CancellationToken.None).ConfigureAwait(false);
             Assert.Equal(fixedApi, updatedApi.ToString());
 
-            fixedApi = "C.Property.set -> void";
+            fixedApi = "C.Property.set -> void" + Environment.NewLine;
             updatedApi = await this.GetUpdatedApiAsync(source, 4, CancellationToken.None).ConfigureAwait(false);
             Assert.Equal(fixedApi, updatedApi.ToString());
 
-            fixedApi = "C.Method() -> void";
+            fixedApi = "C.Method() -> void" + Environment.NewLine;
             updatedApi = await this.GetUpdatedApiAsync(source, 5, CancellationToken.None).ConfigureAwait(false);
             Assert.Equal(fixedApi, updatedApi.ToString());
         }
@@ -730,7 +730,8 @@ private C() { }
 
             this.shippedText = string.Empty;
             this.unshippedText = string.Empty;
-            var fixedUnshippedText = @"C";
+            var fixedUnshippedText = @"C
+";
 
             await this.VerifyCSharpUnshippedFileFixAsync(source, fixedUnshippedText, cancellationToken: CancellationToken.None).ConfigureAwait(false);
         }
@@ -752,7 +753,8 @@ public class C2 { }
             var fixedUnshippedText = @"C
 C.Field -> int
 C2
-C2.C2() -> void";
+C2.C2() -> void
+";
 
             await this.VerifyCSharpUnshippedFileFixAsync(source, fixedUnshippedText, cancellationToken: CancellationToken.None).ConfigureAwait(false);
         }
@@ -848,7 +850,8 @@ public class C2 { }
 C.CC.Field -> int
 C.Field -> int
 C2
-C2.C2() -> void";
+C2.C2() -> void
+";
 
             await this.VerifyCSharpUnshippedFileFixAsync(source, fixedUnshippedText, cancellationToken: CancellationToken.None).ConfigureAwait(false);
         }
@@ -993,7 +996,8 @@ public class C2 { }
             var fixedUnshippedText = @"C
 C.Field -> int
 C2
-C2.C2() -> void";
+C2.C2() -> void
+";
 
             await this.VerifyCSharpUnshippedFileFixAsync(source, fixedUnshippedText, cancellationToken: CancellationToken.None).ConfigureAwait(false);
         }
@@ -1030,6 +1034,24 @@ public class C2 { }
             await this.VerifyCSharpUnshippedFileFixAsync(source, fixedUnshippedText, numberOfFixAllIterations: 2, cancellationToken: CancellationToken.None).ConfigureAwait(false);
         }
 
+        [Fact]
+        public async Task TestAddTrailingNewlineByDefaultAsync()
+        {
+            var source = @"
+public class C
+{
+}
+";
+
+            this.shippedText = string.Empty;
+            this.unshippedText = string.Empty;
+            var fixedUnshippedText = @"C
+C.C() -> void
+";
+
+            await this.VerifyCSharpUnshippedFileFixAsync(source, fixedUnshippedText, cancellationToken: CancellationToken.None).ConfigureAwait(false);
+        }
+
         [Theory]
         [InlineData("", "")]
         [InlineData("\r\n", "\r\n")]