Add test for old behaviour and remove unused method

src/Sdk/DTObjectTemplating/ObjectTemplating/TemplateContext.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Linq;
@@ -120,15 +120,9 @@ namespace GitHub.DistributedTask.ObjectTemplating
             }
         }
 
-        internal void Error(TemplateValidationError error)
-        {
-            Errors.Add(error);
-            TraceWriter.Error(error.Message);
-        }
-
         internal void Error(
-            TemplateToken value,
-            Exception ex)
+           TemplateToken value,
+           Exception ex)
         {
             Error(value?.FileId, value?.Line, value?.Column, ex);
         }

src/Test/L0/Sdk/DTObjectTemplating/TemplateContextL0.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using GitHub.DistributedTask.ObjectTemplating.Tokens;
 using Xunit;
 
@@ -10,22 +11,198 @@ namespace GitHub.DistributedTask.ObjectTemplating.Tests
         [Fact]
         [Trait("Level", "L0")]
         [Trait("Category", "Common")]
-        public void VerifyError()
+        public void VerifyErrorWithTokenAndException()
         {
             TemplateContext context = buildContext();
-            TemplateToken value = new StringToken(1, 1, 1, "some-token");
-            System.Exception ex = new System.Exception();
 
-            List<TemplateValidationError> expectedErrors = new();
-            expectedErrors.Add(new TemplateValidationError("(Line: 1, Col: 1): Exception of type 'System.Exception' was thrown."));
+            List<TemplateValidationError> expectedErrors = new List<TemplateValidationError> { new TemplateValidationError("(Line: 1, Col: 1): Exception of type 'System.Exception' was thrown.") };
 
-            context.Error(value, ex);
+            context.Error(new StringToken(1, 1, 1, "some-token"), new System.Exception());
 
- 
-            Assert.True(expectedErrors.SequenceEqual(toList(context.Errors.GetEnumerator())));
+            List<TemplateValidationError> templateValidationErrors = toList(context.Errors.GetEnumerator());
 
+            Assert.Single(templateValidationErrors);
+            Assert.True(areEqual(expectedErrors, templateValidationErrors));
+        }
 
-            Assert.True(true);
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Common")]
+        public void VerifyErrorWithNullTokenAndException()
+        {
+            TemplateContext context = buildContext();
+
+            List<TemplateValidationError> expectedErrors = new List<TemplateValidationError> { new TemplateValidationError("System.Exception: Exception of type 'System.Exception' was thrown.") };
+
+            context.Error(null, new System.Exception());
+
+            List<TemplateValidationError> templateValidationErrors = toList(context.Errors.GetEnumerator());
+
+            Assert.Single(templateValidationErrors);
+            Assert.True(areEqual(expectedErrors, templateValidationErrors));
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Common")]
+        public void VerifyErrorWithTokenAndMessage()
+        {
+            TemplateContext context = buildContext();
+
+            List<TemplateValidationError> expectedErrors = new List<TemplateValidationError> { new TemplateValidationError("(Line: 1, Col: 1): message") };
+
+            context.Error(new StringToken(1, 1, 1, "some-token"), "message");
+
+            List<TemplateValidationError> templateValidationErrors = toList(context.Errors.GetEnumerator());
+
+            Assert.Single(templateValidationErrors);
+            Assert.True(areEqual(expectedErrors, templateValidationErrors));
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Common")]
+        public void VerifyErrorWithNullTokenAndMessage()
+        {
+            TemplateContext context = buildContext();
+
+            List<TemplateValidationError> expectedErrors = new List<TemplateValidationError> { new TemplateValidationError("message") };
+
+            context.Error(null, "message");
+
+            List<TemplateValidationError> templateValidationErrors = toList(context.Errors.GetEnumerator());
+
+            Assert.Single(templateValidationErrors);
+            Assert.True(areEqual(expectedErrors, templateValidationErrors));
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Common")]
+        public void VerifyErrorWithException()
+        {
+            TemplateContext context = buildContext();
+
+            List<TemplateValidationError> expectedErrors = new List<TemplateValidationError> { new TemplateValidationError("(Line: 2, Col: 3): Fatal template exception") };
+            List<string> expectedTracewriterErrors = new List<string> { "(Line: 2, Col: 3):" };
+
+            context.Error(1, 2, 3, new Exception("Fatal template exception"));
+
+            List<TemplateValidationError> templateValidationErrors = toList(context.Errors.GetEnumerator());
+            ListTraceWriter listTraceWriter = (ListTraceWriter)context.TraceWriter;
+            List<string> tracewriterErrors = listTraceWriter.GetErrors();
+
+            Assert.Single(templateValidationErrors);
+            Assert.True(areEqual(expectedErrors, templateValidationErrors));
+            Assert.True(expectedTracewriterErrors.SequenceEqual(tracewriterErrors));
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Common")]
+        public void VerifyErrorWithExceptionAndInnerException()
+        {
+            TemplateContext context = buildContext();
+
+            List<TemplateValidationError> expectedErrors = new List<TemplateValidationError> { new TemplateValidationError("(Line: 2, Col: 3): Fatal template exception"),
+            new TemplateValidationError("(Line: 2, Col: 3): Inner Exception") };
+            List<string> expectedTracewriterErrors = new List<string> { "(Line: 2, Col: 3):" };
+
+            Exception e = new Exception("Fatal template exception", new Exception("Inner Exception"));
+
+            context.Error(1, 2, 3, e);
+
+            List<TemplateValidationError> templateValidationErrors = toList(context.Errors.GetEnumerator());
+            ListTraceWriter listTraceWriter = (ListTraceWriter)context.TraceWriter;
+            List<string> tracewriterErrors = listTraceWriter.GetErrors();
+
+            Assert.Equal(2, templateValidationErrors.Count);
+            Assert.True(areEqual(expectedErrors, templateValidationErrors));
+            Assert.True(expectedTracewriterErrors.SequenceEqual(tracewriterErrors));
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Common")]
+        public void VerifyErrorWithLineNumbersAndMessage()
+        {
+            TemplateContext context = buildContext();
+
+            List<TemplateValidationError> expectedErrors = new List<TemplateValidationError> { new TemplateValidationError("(Line: 2, Col: 3): Fatal template exception") };
+            List<string> expectedTracewriterErrors = new List<string> { "(Line: 2, Col: 3): Fatal template exception" };
+
+            context.Error(1, 2, 3, "Fatal template exception");
+
+            List<TemplateValidationError> templateValidationErrors = toList(context.Errors.GetEnumerator());
+            ListTraceWriter listTraceWriter = (ListTraceWriter)context.TraceWriter;
+            List<string> tracewriterErrors = listTraceWriter.GetErrors();
+
+            Assert.Single(templateValidationErrors);
+            Assert.True(areEqual(expectedErrors, templateValidationErrors));
+            Assert.True(expectedTracewriterErrors.SequenceEqual(tracewriterErrors));
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Common")]
+        public void VerifyErrorWithNullLineNumbersAndMessage()
+        {
+            TemplateContext context = buildContext();
+
+            List<TemplateValidationError> expectedErrors = new List<TemplateValidationError> { new TemplateValidationError("Fatal template exception") };
+            List<string> expectedTracewriterErrors = new List<string> { "Fatal template exception" };
+
+            context.Error(null, null, null, "Fatal template exception");
+
+            List<TemplateValidationError> templateValidationErrors = toList(context.Errors.GetEnumerator());
+            ListTraceWriter listTraceWriter = (ListTraceWriter)context.TraceWriter;
+            List<string> tracewriterErrors = listTraceWriter.GetErrors();
+
+            Assert.Single(templateValidationErrors);
+            Assert.True(areEqual(expectedErrors, templateValidationErrors));
+            Assert.True(expectedTracewriterErrors.SequenceEqual(tracewriterErrors));
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Common")]
+        public void VerifyErrorWithLineNumbersAndException()
+        {
+            TemplateContext context = buildContext();
+
+            List<TemplateValidationError> expectedErrors = new List<TemplateValidationError> { new TemplateValidationError("(Line: 2, Col: 3): Fatal template exception") };
+            List<string> expectedTracewriterErrors = new List<string> { "(Line: 2, Col: 3):" };
+
+            context.Error(1, 2, 3, new Exception("Fatal template exception"));
+
+            List<TemplateValidationError> templateValidationErrors = toList(context.Errors.GetEnumerator());
+            ListTraceWriter listTraceWriter = (ListTraceWriter)context.TraceWriter;
+            List<string> tracewriterErrors = listTraceWriter.GetErrors();
+
+            Assert.Single(templateValidationErrors);
+            Assert.True(areEqual(expectedErrors, templateValidationErrors));
+            Assert.True(expectedTracewriterErrors.SequenceEqual(tracewriterErrors));
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Common")]
+        public void VerifyErrorWithNullLineNumbersAndException()
+        {
+            TemplateContext context = buildContext();
+
+            List<TemplateValidationError> expectedErrors = new List<TemplateValidationError> { new TemplateValidationError("System.Exception: Fatal template exception") };
+            List<string> expectedTracewriterErrors = new List<string> { "" };
+
+            context.Error(null, null, null, new Exception("Fatal template exception"));
+
+            List<TemplateValidationError> templateValidationErrors = toList(context.Errors.GetEnumerator());
+            ListTraceWriter listTraceWriter = (ListTraceWriter)context.TraceWriter;
+            List<string> tracewriterErrors = listTraceWriter.GetErrors();
+
+            Assert.Single(templateValidationErrors);
+            Assert.True(areEqual(expectedErrors, templateValidationErrors));
+            Assert.True(expectedTracewriterErrors.SequenceEqual(tracewriterErrors));
         }
 
         private TemplateContext buildContext()
@@ -39,7 +216,7 @@ namespace GitHub.DistributedTask.ObjectTemplating.Tests
                 maxEvents: 1000000,
                 maxBytes: 10 * 1024 * 1024),
                 Schema = null,
-                TraceWriter = new EmptyTraceWriter(),
+                TraceWriter = new ListTraceWriter(),
             };
         }
 
@@ -53,5 +230,46 @@ namespace GitHub.DistributedTask.ObjectTemplating.Tests
             }
             return result;
         }
+
+        private bool areEqual(List<TemplateValidationError> l1, List<TemplateValidationError> l2)
+        {
+            if (l1.Count != l2.Count) return false;
+
+            var twoLists = l1.Zip(l2, (l1Error, l2Error) => new { Elem1 = l1Error, Elem2 = l2Error });
+
+            foreach (var elem in twoLists)
+            {
+                if (elem.Elem1.Message != elem.Elem2.Message) return false;
+                if (elem.Elem1.Code != elem.Elem2.Code) return false;
+            }
+            return true;
+        }
+
+        internal sealed class ListTraceWriter : ITraceWriter
+        {
+
+            private List<string> errors = new();
+            private List<string> infoMessages = new();
+            private List<string> verboseMessages = new();
+            public void Error(string format, params object[] args)
+            {
+                errors.Add(string.Format(System.Globalization.CultureInfo.CurrentCulture, $"{format}", args));
+            }
+
+            public void Info(string format, params object[] args)
+            {
+                throw new NotImplementedException();
+            }
+
+            public void Verbose(string format, params object[] args)
+            {
+                throw new NotImplementedException();
+            }
+
+            public List<string> GetErrors()
+            {
+                return errors;
+            }
+        }
     }
 }