Improve the ability of GenericAnalyzerTest to report misconfigured tests

Author: sharwell

StyleCop.Analyzers/StyleCop.Analyzers.Test/SpacingRules/SA1000UnitTests.cs

@@ -964,7 +964,7 @@ namespace Namespace
             var test = new CSharpTest
             {
                 TestCode = testCode,
-                FixedCode = fixedTest != testCode ? fixedTest : null,
+                FixedCode = fixedTest,
             };
 
             test.ExpectedDiagnostics.AddRange(expected);
@@ -997,7 +997,7 @@ class ClassName
             var test = new CSharpTest
             {
                 TestCode = testCode,
-                FixedCode = fixedTest != testCode ? fixedTest : null,
+                FixedCode = fixedTest,
             };
 
             test.ExpectedDiagnostics.AddRange(expected);

StyleCop.Analyzers/StyleCop.Analyzers.Test/SpacingRules/SA1001UnitTests.cs

@@ -374,7 +374,7 @@ void f(int x, int y) {{ }}
             var test = new CSharpTest
             {
                 TestCode = originalCode,
-                FixedCode = fixedCode != originalCode ? fixedCode : null,
+                FixedCode = fixedCode,
             };
 
             test.ExpectedDiagnostics.AddRange(expected);

StyleCop.Analyzers/StyleCop.Analyzers.Test/SpacingRules/SA1009UnitTests.cs

@@ -236,8 +236,8 @@ public async Task TestNotReportedWhenFollowedByUnaryPlusOrMinusAsync(string oper
             var ignoredStatement = $"var i = (int) {operatorToken}2;";
             var correctStatement = $"var i = (int){operatorToken}2;";
 
-            await this.TestWhitespaceInStatementOrDeclAsync(ignoredStatement, string.Empty, EmptyDiagnosticResults).ConfigureAwait(false);
-            await this.TestWhitespaceInStatementOrDeclAsync(correctStatement, string.Empty, EmptyDiagnosticResults).ConfigureAwait(false);
+            await this.TestWhitespaceInStatementOrDeclAsync(ignoredStatement, null, EmptyDiagnosticResults).ConfigureAwait(false);
+            await this.TestWhitespaceInStatementOrDeclAsync(correctStatement, null, EmptyDiagnosticResults).ConfigureAwait(false);
         }
 
         [Fact]
@@ -1019,12 +1019,12 @@ public object Test
 }}
 ";
             string originalCode = string.Format(template, originalStatement);
-            string fixedCode = string.Format(template, fixedStatement);
+            string fixedCode = string.Format(template, fixedStatement ?? originalStatement);
 
             var test = new CSharpTest
             {
                 TestCode = originalCode,
-                FixedCode = expected.Length > 0 ? fixedCode : null,
+                FixedCode = fixedCode,
             };
 
             test.ExpectedDiagnostics.AddRange(expected);

StyleCop.Analyzers/StyleCop.Analyzers.Test/SpacingRules/SA1011UnitTests.cs

@@ -261,7 +261,7 @@ public async Task TestClosingBracketFollowedByNoSpaceAndIncrementOrDecrementOper
                 @"var i = new int[1];
             i[0]{0};", operatorText);
 
-            await this.TestWhitespaceInStatementOrDeclAsync(validStatament, string.Empty, EmptyDiagnosticResults).ConfigureAwait(false);
+            await this.TestWhitespaceInStatementOrDeclAsync(validStatament, null, EmptyDiagnosticResults).ConfigureAwait(false);
         }
 
         [Theory]
@@ -375,12 +375,12 @@ void DoIt()
 }}
 ";
             string originalCode = string.Format(template, originalStatement);
-            string fixedCode = string.Format(template, fixedStatement);
+            string fixedCode = string.Format(template, fixedStatement ?? originalStatement);
 
             var test = new CSharpTest
             {
                 TestCode = originalCode,
-                FixedCode = expected.Length > 0 ? fixedCode : null,
+                FixedCode = fixedCode,
             };
 
             test.ExpectedDiagnostics.AddRange(expected);

StyleCop.Analyzers/StyleCop.Analyzers.Test/Verifiers/GenericAnalyzerTest.cs

@@ -102,7 +102,7 @@ public async Task RunAsync(CancellationToken cancellationToken)
 
             var expected = this.ExpectedDiagnostics.ToArray();
             await this.VerifyDiagnosticsAsync(new[] { this.TestCode }, expected, filenames: null, cancellationToken).ConfigureAwait(false);
-            if (this.FixedCode != null)
+            if (this.HasFixableDiagnostics())
             {
                 await this.VerifyDiagnosticsAsync(new[] { this.FixedCode }, this.RemainingDiagnostics.ToArray(), filenames: null, cancellationToken).ConfigureAwait(false);
                 await this.VerifyFixAsync(numberOfIncrementalIterations: this.NumberOfIncrementalIterations, numberOfFixAllIterations: this.NumberOfFixAllIterations, cancellationToken: cancellationToken).ConfigureAwait(false);
@@ -123,6 +123,31 @@ public async Task RunAsync(CancellationToken cancellationToken)
         /// <returns>The <see cref="CodeFixProvider"/> to be used for C# code.</returns>
         protected abstract IEnumerable<CodeFixProvider> GetCodeFixProviders();
 
+        private bool HasFixableDiagnostics()
+        {
+            var fixers = this.GetCodeFixProviders().ToArray();
+            if (HasFixableDiagnosticsCore())
+            {
+                if (this.FixedCode != null)
+                {
+                    return true;
+                }
+
+                Assert.Empty(this.RemainingDiagnostics);
+                return false;
+            }
+
+            Assert.True(string.IsNullOrEmpty(this.FixedCode) || this.FixedCode == this.TestCode);
+            Assert.Empty(this.RemainingDiagnostics);
+            return false;
+
+            // Local function
+            bool HasFixableDiagnosticsCore()
+            {
+                return this.ExpectedDiagnostics.Any(diagnostic => fixers.Any(fixer => fixer.FixableDiagnosticIds.Contains(diagnostic.Id)));
+            }
+        }
+
         private static bool IsSubjectToExclusion(DiagnosticResult result)
         {
             if (result.Id.StartsWith("CS", StringComparison.Ordinal))